IGCSE ICT 0417 Notes
Contents:
1. Types and Components of a Computer system
2
2. Input and Output Devices
11
3. Storage Devices and Media
20
4. Networks and the effects of using them
24
5. The Effects of using IT
34
6. ICT Applications
37
7. The Systems Life Cycle
51
8. Safety and security
58
9. Audience
63
10. Communication
65
11. File Management
70
12. Images
73
Practical Notes for Paper 1
75
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1. Types and Components of a Computer system
1.1 Hardware and Software:
Hardware - Physical components of a computer system
Internal Hardware Devices:
Internal Hardware Device
Description
Processor/CPU
‘Brain’ of the computer.
Controls actions and carries
out calculations and
processing of data.
Motherboard
Main printed circuit board that
connects various components
in a computer system
Random Access Memory
(RAM)
A form of computer memory
that is volatile and stores
data temporarily. When the
power button is switched off,
all data is lost. It stores the
data that is part of the
operating system currently
in use and can be altered.
Read-Only Memory (ROM)
A form of computer memory
that is non-volatile and
stores data permanently.
When the power button is
switched off, data is still
stored. It stores the
‘boot-strap’ instructions to
start a computer and cannot
be altered
Picture
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1. Types and Components of a Computer system
Video Cards
An expansion card that
allows the computer to send
graphical information to a
video display device
Sound Cards
An expansion component
used in computers to send
and receive audio
Internal Hard Disk Drives
The secondary storage
device located inside a
computer system
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1. Types and Components of a Computer system
External Hardware Devices:
External Hardware Device
Description
Monitor
Display images generated by
the computer
Keyboard
Used to input text
commands into a computer
Mice
Used to control a point on
the screen.
Printer
Used to output copies of
information stored on a
computer.
External storage devices
Memory sticks connect to a
computer and are used to
store and transfer data.
Picture
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1. Types and Components of a Computer system
Software - Programs that control the operation of the computer or the processing of
electronic data.
- Application Software - Programs that allows the user to carry out specific tasks
- System Software - Programs that control and manage the computer's hardware and
runs the application softwares
Application Software:
● Word processing
○ Prepare essays, reports...
● Spreadsheet
○ Create to organise and
manipulate numerical data
● Database management system
○ Insert and organise data
using field and records
● Control software
○ Compares sensor readings
and decide on an output
● Measurement software
○ Sensors take readings which
are processed by a computer
● Applets and apps
○ Runs of mobile phones
● Photo editing software
○ Edit digital images
● Video editing software
○ Edit and format videos
● Graphics manipulation software
○ Create and edit bitmap and
vector graphics.
System software:
● Compilers
○ Translates a program written
in a specific language so that
it can be understood by the
computer
● Linkers
○ Combines object files into a
single program
● Device drivers
○ Allows hardware devices to
run on the computer.
● Operating Systems
○ Manages computer functions
● Utilities
○ Maintain computer’s
resources and performance
by running specific tasks
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1. Types and Components of a Computer system
1.2 The Main Components of a computer system:
Central Processing Unit:
● Hardware that contains the internal storage/control unit
● Carries out instructions of a computer program
● Performs basic arithmetic calculations/logical
operations/input and output operations
Internal Memory: RAM and ROM
Random Access Memory (RAM)
Read Only Memory (ROM)
Stores information temporarily
Stores information permanently
Volatile - when power button switched off, all
data is lost
Non-volatile - when power button switched
off, all data is still stored
Stores files of the operating system
currently in use
Stores ‘boot-strap’ information needed to
setup a computer
Read and write (altered)
Read only
Input devices: Any device which allows us to get information from the outside world into a
computer so that it can be stored and processed in a digital form
Output devices: Any device which can take the data stored inside a computer in a digital
form and turn it into another format which we can process
Peripheral devices: Non-essential hardware devices that can connect to a system
externally. The system can function without them.
Secondary/Backing Storage: Used to store and backup data that is not instantly needed
by the computer. It permanently stores data and programs for a long time.
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1. Types and Components of a Computer system
1.3 Operating Systems:
Operating System: A software program that manages the general operation of a computer
system.
Command Line Interface (CLI):
● Text-based user interface used to view and
manage computer files
● Enables the user to interact with the computer by
typing a series of text commands
Graphical User Interface (GUI):
● Enables the user to interact with the computer by
using pictures, graphics and icons
● Main features are (WIMP): Windows, Icons,
Menus, Pointers
Command Line Interface (CLI)
Graphical User Interface (GUI)
Advantages
Disadvantages
Advantages
●
●
●
●
●
●
●
User directly
communicates
with computer
Wider range of
commands
Needs little
computer power
●
●
User must
remember
complex
commands
Need to type in
commands
accurately
Commands
difficult to be
edited once typed
●
Quicker
Easier
Less chance of
errors
User does not
need to
remember the
commands
Disadvantages
●
●
Smaller range of
commands
Require more
computer power
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1. Types and Components of a Computer system
1.4 Types of Computers:
Type
Uses
Advantages
Desktop
Computer that is
(standalone) not connected to a
network and is
used by one
person each time.
Self-sufficient
Personal/
work use
●
●
Desktop
(networked)
Computers that are
joined together on
a network and are
used to share
information. Used
by multiple users.
Share
resources
and files
Laptop
Portable computers
(standalone) that can be used
everywhere by one
person
Personal/
work use
Laptop
(networked)
Portable computers
that are connected
to a network used
to share
information
Tablet
(includes
wireless &
3/4G)
Smartphone
Description
Disadvantages
Personal use
●
Damage control - if something goes
wrong, only the standalone is
●
affected
●
Does not affect other computer
users
Restricted to a
single computer
Harder to monitor
Loose cables
Convenient resource sharing - can
access work from any computer
Software easily updated
Increases storage capacity
Fewer printers/scanners needed
All computers access the internet
through one connection
●
Increased risk of
security issues
from hackers
Increased risk of
computer viruses
and malware
Long print queues
●
●
●
●
Smaller and lighter
Rechargeable battery
Personal use
Portable
●
●
Share
resources
and files
●
●
●
Fewer printers/scanners needed
Convenient resource sharing
Software easily updated
●
A portable
computer that is a
touch screen
primary input
device. Have SIM
cards to access
3G&4G technology
Multimedia,
internet
access,
and using
application
software
●
●
●
●
●
Smaller and lighter
Portable
Touchscreen
Built-in cameras
Longer battery life (than mobile
phones)
Wireless, 3G/4G, Bluetooth
connection
●
A mobile phone
with highly
advanced features
and are
multifunctional
devices.
Make
phone calls
and text
messages,
multimedia,
internet
access
●
●
Most portable
More likely to have mobile phone
with you
Easier to use mobile phone on the
move
Smaller in size so can fit in pocket
●
●
●
●
●
●
●
●
●
●
●
●
●
●
●
●
●
●
●
●
Limited battery life
Smaller
keyboards
Prone to theft
Hotter
Increased risk of
security issues
from hackers
Increased risk of
computer viruses
and malware
Less storage
space
Slower
performance
Touchscreen hard
to use for detailed
tasks.
Small screen
Limited storage
Prone to theft
Short battery life
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1. Types and Components of a Computer system
1.5 Impact of emerging technologies:
Artificial Intelligence:
Computer science focused on creating computers that stimulate human intelligence
Areas being developed:
● Game Playing
● Expert Systems
● Language
● Robotics
Impacts on daily life:
● Increased leisure time
● Increased personal safety
● Improved medical care
● Safer transport
Biometrics:
Where parts of a person’s body is used for identification methods as a means of security
Areas being developed:
● Fingerprints
● Face, Eye and Voice recognition
Impacts on daily life:
● Better airport/building security
● More secure mobile phones
● Reduced car theft
Robots:
Used to perform a wide range of specific tasks, usually in the manufacture industry
Areas being developed:
● Dangerous jobs
● Exploring extreme environments
● Repetitive manufacturing jobs
● Moving heavy objects
Impacts on daily life:
● Increased personal time
● More efficient manufacturing
● Loss of jobs
● Safer working environment
Quantum Cryptography:
Encryption that allows messages and data to be sent with complete privacy using photons
Impact on daily life:
● Secure voting
● Secure bank transfers
● Secure personal information
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1. Types and Components of a Computer system
Vision Enhancement:
Uses video technology that is projected to the user using lens
Computer Assisted Translation (CAT):
Where a human translator uses computer software to help in the translation process
Areas being developed:
● Spell checkers
● Translation memory software
● Language search engine
Impacts on daily life:
● More accurate documents
● More multilingual society
● Quicker and more efficient translations
3D and Holographic Imaging:
Technique where images appear to be three-dimensional
Impacts on daily life:
● Improved security
● Better movie experiences
● Greater data storage
Virtual Reality:
Computers create an artificial environment that users can interact with as if it was real
Purposes:
● Allow architect to walk around buildings
● Training soldiers in combat
● Training surgeons
Impacts on daily life:
● Improved medical surgeons
● Larger and stronger buildings
● More effective treatment of phobias
● Training in dangerous situation
● More realistic situation
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2. Input and Output Devices
2.1 Input devices and their uses:
Device
Uses
Advantages
Disadvantages
Keyboard
Input data into
applications and
typing commands
into a computer
system
●
●
●
Used to input
numbers into a
computer system,
however, some
can enter simple
text and symbols.
●
Control a pointer
on the screen to
click on icons,
selecting windows
or positioning the
pointer
●
Numeric Keypad
Mouse
Touchpad
●
●
●
●
●
Used as a pointing ●
device on laptops
●
Trackerball
Used by users
who have limited
movement in their
wrist
Fast data entry
Easy to use
●
●
Faster to enter
numbers
Small, so can
easily fit on
smaller devices
●
Faster to select
icons
Easy to use
Small and do not
take up much
space
●
●
●
●
Painful for people
with wrist and hand
problems
Large
Slow data entry
compared to
automatic data entry.
Keys can be too
small
Difficult to enter text
Painful for people
with wrist and hand
problems
Can pick up dirt
which will affect the
accuracy
Need flat surface
Easier than
●
QWERTY
●
keyboard
Built into laptops portable
●
Difficult to control
Painful for people
with wrist and hand
problems
More difficult to use
than mouse
Easier to use
compared to
mouse
More accurate
positioning of
pointer
More expensive
Not familiar to many
users
●
●
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2. Input and Output Devices
Remote Control
Used to control
other devices
using infra-red
signals
●
Used in computer
games and
simulators to
control a pointer
on a screen
●
Driving Wheel
Used by gamers
in racing/driving
computer games
and in simulators
Touch Screen
Joystick
Scanner
Digital Cameras
Can be used from ●
a distance
Operate in unsafe
environments
●
Difficult for people
with limited hand
movement
Remote control
signals can be
blocked by walls
Easier to control
than a keyboard
Easy to learn
Used by disabled
people
●
●
Harder to use
compared to mouse
Painful for people
with hand/wrist
issues
Difficult to enter text
●
Better driving
experience
●
More expensive
Allow users to
input commands
into a computer by
touching
buttons/icons on a
screen
●
Fast and easy to
use
No training
needed
●
Limited number of
options
Expensive
Screen can become
dirty
Options can be
accidentally selected
Used to enter
information on
paper into a
computer
●
●
Used to take
photographs and
videos.
●
●
●
●
●
●
●
●
●
●
●
●
Easy to use
Digital data can
be backed up
Photos can be
edited
●
●
Higher resolution ●
images
No need to
develop films
●
Memory cards
can store
thousands of data
copies
Scanned images are
lower quality
Scanned images
take up a lot of disk
space
Camera user must
have good computer
skills
Not all digital
cameras produce
good quality images
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2. Input and Output Devices
Microphones
Graphics Tablet
Video Camera
Webcam
Used to input
analogue sounds
into a computer.
Used in voice
recognition
softwares.
●
Recorded audio
can be
automatically
typed into word
processing
softwares
Cheap
●
Used by artists
and designers to
create and store
digital graphics in
a computer
●
Easy to draw
images with
stylus
Accurate method
of drawing
●
Very expensive
compared to mouse
Used to record
video footage
●
●
Can record in HD
Footage can be
edited on a
computer
●
HD movies takes up
storage
Costly
Directly connected
to a computer and
can capture digital
images and
videos.
●
Allows long
distance video
calls
Video conference
business
meetings and job
interviews can be
conducted
Parent can keep
an eye on
children
Security
purposes
●
●
●
●
●
●
●
●
●
●
Sound files take up a
lot of space
Speaking words into
word processors is
not accurate
Background noises
can interfere
Poor image/video
quality
Fixed position cannot move around
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2. Input and Output Devices
Sensors: a device that automatically inputs data into a computer system where the data is
constantly changing and can be measured
An Analogue to Digital Converter (ADC) is used to convert analogue data into digital for the
computer to read.
Sensor
Used in:
Temperature
Greenhouses to measure temperature
Pressure
Burglar alarms
Light
Burglar alarms, automatic doors etc..
Sound
Burglar alarms, voice recognition
Humidity/Moisture
Automatic greenhouses, Environmental
monitoring
Movement
Detect movement that could trigger an alarm
pH
Chemical manufacturing
Advantages:
Disadvantages:
●
●
●
●
Readings taken are more accurate
Monitor information constantly
Respond to information immediately
No need for humans to operate
●
Faulty sensors can give incorrect
results
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2. Input and Output Devices
2.2 Direct data entry and associated devices:
Device
Uses
Advantages
Disadvantages
Magnetic Stripe Reader
Used to read data found on
magnetic stripes found on
the back of cards
●
●
●
●
Uses:
● ATM - cards
● EFTPOS
● Door keys
●
Entering data is fast
No data entry errors
Strips are robust and
are no easily affected by
water
Data held cannot be
read by eye - security
●
●
●
●
Chip and Pin reader
Radio Frequency
Identification Readers
(RFID)
Used to make payments
electronically at EFTPOS
terminals.
●
Uses:
● Supermarkets
● Restaurants
● Cafes
●
Reads information stored
on tags using radio waves.
RFID tags can be attached
to animals/objects/people.
●
Uses:
● Track movement
● Identify Pets
● Airports - track
luggage
● Manage stocks
(supermarkets)
●
●
●
●
●
●
●
More secure than
magnetic stripe readers
Information harder to
clone
Can hold more data
than magnetic stripe
readers
Portable
●
Hold more data than
barcodes
Data can be read from
long distances
Tags can be read
without direct line of
sight
Faster to read
Writeable
Can be made very small
●
●
●
●
Magnetic stripe can
only hold a small
amount of data
Cards need to be in
contact with reader
Stripe can get
damaged
Magnetic stripes can
be easily duplicated
Easily lost
Possible to forget your
PIN
People can look over
your shoulders as you
enter the PIN
If thieves access
handheld scanner, can
steal information
More expensive
Tags can interfere with
each other
RFID Tags made of:
● Microchip - stores
and processes
information
● Antenna - receive
and transmit data
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2. Input and Output Devices
Magnetic Ink Character
Recognition/Reader
(MICR)
Used to read characters
printed in special magnetic
ink and convert it into a
form in which the computer
can understand.
Uses:
● Cheques
● Passport numbers
Optical Mark
Recognition/Reader
(OMR)
Used to read marks that
are made in pen or pencil.
The position of the mark is
stored in the computer’s
memory.
●
●
Processed quickly
Greater security difficult to forge
Characters cannot be
changed once printed
Less errors
Information can still be
read if characters is
written over
●
●
More expensive
Limited number of
different characters
can be read
●
●
●
Fast
Accurate
Save money
●
If incorrectly filled,
cannot be read
properly
Can only read shaded
areas - no text
●
●
●
Fast
Cheap
Avoids typing errors
●
●
●
●
●
Uses:
● Read multiple
choice
examinations
● Lottery tickets
Optical Character
Recognition/Reader
(OCR)
Used to scan text from
hardcopies and transfers
them into an editable form
which can be edited in
word processors
●
Difficult to read messy
handwriting
Not 100% accurate
Uses:
● Processing of
passports
● Digitizing books
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2. Input and Output Devices
2.3 Output devices and their uses:
Device
Uses
Advantages
Disadvantages
CRT Monitor (Cathode
Ray Tube)
Old, heavy and bulky
monitors that allow users to
instantly see outputs from the
computer.
●
Can be used with light
pens
Larger range of colours
than TFT monitors good resolution
Cheaper
●
●
●
●
●
TFT/LCD Monitor
●
Large and bulky
Create a lot of heat
Screen glare and
screen flicker
Need more power
than TFT
Thin film transistor monitor
allows the user to instantly
see outputs from the
computer.
●
●
●
●
●
Lightweight
Thin
Produce less glare
Use less power
Produce less heat than
CRT
●
●
IPS/LCD Monitor
Used by creative
professionals.
●
●
Wide viewing angles
Better colour
reproduction
●
More expensive
LED Monitor
Used as the display output for
flat screens. LED monitors
use an LED panel as their
light source.
●
●
Energy efficient
Produces better light
●
●
Expensive
Colour can shift
due to age and
temperature
Touch screen (as an
output device)
Users use their fingers or a
stylus to interact with the
computer.
●
No need for additional
buttons
Easy to use
●
Screen can
become dirty due
to fingerprints
Difficult to input
many commands
and information
●
●
●
Lower resolution
Lower picture
quality
Cannot be used
with light pens
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2. Input and Output Devices
Multimedia Projector
Laser Printer
Project images on the
computer monitor onto a very
large screen. Used for
training presentations and
large advertising
●
Produce high quality hard
copy outputs and can print
large amounts at a fast rate.
●
●
Used when high quality
printouts and high volume is
needed (e.g. school, office)
Inkjet Printer
Produce high quality outputs
by spraying ink on paper.
Used when few single paged
printouts are needed (e.g.
photographs)
Dot Matrix Printer
Often called an ‘Impact
printer’ where pins are
pressed against an inked
ribbon which produces an
imprint on paper.
●
●
●
●
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●
●
●
●
●
●
●
Larger audience can
view
Enhance viewer’s
experience
●
Fast printing rate
Toner cartridges last a
long time
Can handle high
volumes of printing
Quiet
Reliable
●
High quality output
Cheaper to buy
Smaller - takes up less
space
Do not produce ozone
Quiet
●
●
More resistant to a dirty
and dusty environment
Cheap to buy and
maintain
Can print carbon copies
●
●
●
Noisy
Slow to print
Poor print quality
Can print larger
printouts
High printout quality
●
●
Slow printout time
Expensive to buy
and maintain
●
●
●
●
●
●
Lower image
quality
Expensive
Environmental
unfriendly
Use more power
than inkjets
More expensive to
buy
Larger in size
Slow printing rates
Ink cartridges don’t
last long
Expensive to run
Printouts easily
smudge
Used to print shop receipts,
carbon copies etc..
Wide Format Printer
Generally used when large
format printing is required.
Used for printing banners,
billboards, posters etc...
●
●
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2. Input and Output Devices
3D Printer
Speakers
Printer that allows us to print
three-dimensional solid
objects by printing in layers.
●
Used in the medical, car
industries and
computer-aided design (CAD)
applications.
●
Speakers are used to output
sounds. They can be
connected directly to a
computer or built into the
monitor.
●
●
●
Produces prototypes
quickly
Can find design flaws
early
Environmental friendly
●
●
Everyone in the room
can hear the sound
Help blind people use
computers
●
Cheap
Speed Variation
●
●
●
●
Limited in size
People can print
dangerous items
Copyright issues
Expensive
Sound can disturb
people
High quality
speakers are
expensive
Used to listen to music, watch
movies, play games etc...
Motors
Used in automatic washing
machines, DVD players.
●
●
●
Not suitable in
clean
environments
High maintenance
Buzzers
Used in microwave ovens and ●
alarm systems
Small - doesn’t take up
space
●
Irritating sound
Heaters
Used in central heating
systems and automatic
greenhouses
●
●
Heats up quickly
Some are portable
●
Can only heat up
one area
Lights/lamps
Used in security lights and
greenhouses
●
●
Easy to install
Can be used as a
signal
●
●
●
Fragile
High heat
output
Easily dimmed
Actuators: Part of the control process and the digital signals sent from the computers to
actuators affect and control the world.
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3. Storage Devices and Media
3.1 Storage Devices and Media:
Writing data: Storing data (saving)
Reading data: Getting data (opening)
Backing data: process of making copies of files to a different medium
in case of a problem with the main secondary storage device.
Sequential Access (Serial Access)
Direct Access (Random Access)
Stores files one by one in a sequence
Stores files so they can be instantly accessed
Data must be searched through one by one until the
required information is found
No searching
Very slow
Faster
Examples: cassette tape, magnetic tape...
Examples: DVD, CD-ROM, Blu-ray…
Data storage capacity:
● Measured in bytes
● 1000B = 1kB (kilobyte)
● 1,000,000B = 1MB (megabyte)
● 1,000,000,000B = 1GB (gigabyte)
● 1,000,000,000,000B = 1TB (tetrabyte)
Storage devices:
Uses:
Advantages:
Disadvantages:
Magnetic Backing Storage Media
Fixed Hard Disk and
Drives
Main backing storage used to
store operating systems, software
applications and online databases
●
●
●
High storage capacities
Fast data transfer rate
Fast data access time
(direct access)
●
●
Portable and
Removable Hard
Disk Drive
Device that connects externally to
the computer using a USB port and
is used to store personal backup
data and transfer files between
devices.
●
●
●
●
Portable
High storage capacities
Fast data transfer rate
Fast data access time
(direct access)
●
●
●
Hard drives can
malfunction
due to incorrect
shutdown
procedures.
Not portable
because ‘fixed’
into a computer
More prone to
errors
Small size - can
be misplaced
More expensive
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3. Storage Devices and Media
Magnetic Tape Drives Magnetic tape is a thin strip of
and Magnetic Tapes
magnetic coated plastic which is
wrapped onto a reel. Data is stored
in binary form and is accessed by
serial access.
●
●
●
Robust
High storage capacities
Fast data transfer rate
Used when large amounts of data
is needed to be backed up schools/businesses
●
●
●
Used to store server backups
Slow data
access rate
(serial access)
Another tape is
needed when
updating
Affected by
magnetic fields
- strong magnets
can corrupt data.
Optical Backing Storage Media (CD/DVD/Blu-ray): use light sources to read/write data onto a disc. Data is
read by shining the laser beam onto the surface of the disc
CD ROM/DVD ROM
Optical disks that are read-only
●
memory and data is stored as a
series of pits (1) and lands (0). Data ●
is accessed via direct access.
Holds significantly more
data than floppy disks
Less expensive
●
Slower data
access times
and data transfer
rates than hard
disks
Cheaper than RW disks
Once burned and
finalised, disc is read
only and data is
impossible to delete
●
Only recordable
once impossible to
update disc
If error occur,
must throw away
disc
Not all CD/DVD
players can read
CD R/DVD R
disks
CD-ROMS used to store music,
files, software
DVD-ROMS used to store films,
and applications which require the
prevention of deletion of the data
CD R/DVD R
‘R’ means recordable; it becomes
CD-ROM/DVD-ROM once finalised.
Data is accessed via direct
access. A laser beam produces
heated spots (1) and unheated
spots (0).
●
●
Used to backup data and music
(CD-R) and films (DVD-R).
CD RW/DVD RW
‘RW’ means rewritable - data can
be recorded many times. Data is
accessed via direct access. Spots
are used to represent data.
●
●
●
●
Can be written over many ●
times
Data can be updated
Data can be
accidentally
overwritten
Used to record TV programmes,
music and in applications which
require the updating of information.
21
LivingLegend - MsHana
3. Storage Devices and Media
DVD RAM
Data is accessed via direct access
and can be read and written at the
same time. Shiny and dull marks
are used to represent data.
●
●
●
Used in recording devices and
camcorders to store videos.
Blu-ray Discs
Data is read by blue lasers and
accessed using direct access. CD
and DVD are read by red lasers.
Used in home video consoles, and
storing high quality videos
●
●
●
●
Long life
Can be rewritten many
times
Data can be read and
written at the same time
●
High storage capacity
Fast data transfer rate
Fast data access speed
Automatically comes with
a secure encryption
system.
●
●
●
●
Relatively
expensive
Not very
compatible with
many devices
Relatively
expensive
Fewer movie
titles on Blu-ray
format
Only work in
Blu-ray drives
Solid State Backing Storage - any memory device with no moving parts and are based on electronic circuits.
Solid State Drives
(SSDs)
Used in desktops (PC) and
laptops and stores files
permanently.
Used to store music/video files,
operating systems, software
applications etc...
Flash Drives (pen
drive/memory
stick/USB stick)
Small portable external storage
devices used to transfer and
back-up data between computers.
●
●
●
●
●
●
●
●
●
Flash memory cards
Known as ‘Secure Digital cards’
(SD cards). They are small and
rectangular in shape and are a
form of Electronically Erasable
Programmable Read Only Memory
(EEPROM).
Used to store photos on digital
cameras and are used in mobile
phones.
●
●
More reliable - no
moving parts
Fast data access time
Use less power and
produce less heat
Run silently
●
Small and lightweight
Portable
Robust
Compatible with many
devices
Large storage
capacities
●
Very small - portable
and compact
Robust
●
●
●
●
●
●
Smaller storage
capacity
Expensive
Cannot
write-protect
data
Easy to lose
Incorrect
removal will
corrupt data
More expensive
per gigabyte
Lower storage
capacity than
hard disks
Smaller size easily stolen
22
LivingLegend - MsHana
4. Networks and the effects of using them
4.1 Networks:
Networks - two or more computers connected so that they can share resources
Advantages of computer networks
Disadvantages of computer networks
Resources/data can be shared
If one part of network fails, can cause whole
network to break down
Software can be easily updated
Greater risk of virus
All computers access internet through one
connection
Too few printers can develop printing
queues
Can access work from any computer
Greater risk of hackers
Router - Transfers data from one network to another using IP address to figure out the
best/fastest route possible
● Transfer data between networks (receives and sends data packets to switch with
correct IP address)
● Connects networks/computers to the internet
● Connects LANs/networks together
● Connects a LAN to a WAN
Each data packet contains:
● Header to identify data packets
● Number of data packets that make up the message
● Identity number of each packet
● The sender’s and receiver’s IP address
○ Internet Protocol address - unique identifier
set up by a network manager/ISP that consists
of 4 numbers separated by full stops. IP addresses can change but it should
match the network it is on.
○ Routers store IP addresses in a routing table, which stores the MAC address of
the device
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LivingLegend - MsHana
4. Networks and the effects of using them
Common network devices:
Device
Network interface cards
Uses
●
●
Hubs
●
●
●
Bridges
●
●
Switches
●
●
●
Modems
●
●
●
●
●
Used to connect individual computers/devices
to a network
Contains the MAC address used to identify the
computer to the network
Use to connect devices to form a LAN.
Transfers data packets received at one of its
ports and broadcast it to every computer on
the LAN
Non-intelligent - lack of data management
makes it slow, inefficient and low security
Devices that connect one LAN to another LAN
using the same protocol (communication
rules) so that they function as one LAN
Direct data packets to specific networks
Type of hub used to connect devices to form a
LAN
Switch checks the data packet received and
works out the destination address and sends
the data to the specific computer(s) only.
Uses MAC address and look up table to
locate the destination of the device
Modems means ‘modulator demodulator’
Allows computers to connect to networks
(internet)
(modulates) Convert digital computer data
into analogue signals for transmission over an
existing telephone line
(demodulates) Convert analogue signals into
digital signals to allow the computer to process
data
Contains Digital to Analogue Converter (DAC)
and Analogue to Digital Converter (ADC)
24
LivingLegend - MsHana
4. Networks and the effects of using them
WiFi:
● Allows computers to connect to each other wirelessly,
● Use radio frequencies and radio waves as the carrier of
data transmission
● Routers commonly used to provide hotspots for computers
to connect to the internet
● Devices can connect only within Wireless Access Point
(WAP)
How computers connect to WiFi:
● Laptops transmits data by radio waves to a wireless transmitter (WAP) where it
receives information from a network through connection (broadband) and converts the
radio waves into data and transmits them to destination computer
Bluetooth:
● Allows computers to connect to each other wirelessly
● Use radio frequencies and radio waves as the carrier of data
transmission
● Known as Wireless Personal Area Network (WPAN)
How computers connect to bluetooth:
● When connecting, the device picks up one of the 79 channels at
random, known as spread-spectrum frequency hopping
Bluetooth
Similarities
WiFi
Wireless communications
Use radio frequencies and radio waves as the carrier of data transmission
Use security when sending out data
Differences
Slower data transfer rate
Faster data transfer rate
Smaller range of transmission
Greater range of transmission
Uses WEP (wireless equivalent
privacy) and WPA (Wi-Fi protected
access) as a type of data
transmission security system
Uses key matching encryption as a
type of data transmission security
system
Connects less devices
Connects more devices
Cheaper
More expensive
Bluetooth devices are battery
operated - need to be recharged
Wi-Fi do NOT necessary use batteries
More useful to transfer data between More suitable for full scale networks
two devices
25
LivingLegend - MsHana
4. Networks and the effects of using them
How to set up and configure a small network:
Buy Hardware:
● Switches, hubs - to link devices together
● Network cables - to connect devices together
● Router - to connect LAN to internet (WAN)
● Network devices (printers, scanners…)
Buy Software:
● Firewall - to protect network from hacking
● Servers - manage network security & store files
● Email account
● Web browser
Organisation:
● Setting up an account with an internet service provider (ISP)
○ ISP is a company that gives you access to the internet
● Configuring the hardware and software so they work correctly together
● Acquire network licence
● Setting up privileges - so each user can only access own area or common shared area
● Install network cards
Internet: Worldwide public network of networks
Uses: Browse world wide web (www)
Send and receive emails
Transfer/share files
Video conferencing
E-commerce/social media/blogging
Intranet: Private network that uses the same protocols as the internet, but usually confined to
a small organisation and is not available to the general public.
Uses: Viewing internal web pages
Sending internal emails between workers
Sharing of internal documents
Internet
Intranet
Term ‘internet’ comes from international
network
Term ‘intranet’ comes from internal restricted
access network
Used to provide information covering a
wider range of topics
Used to give local information relevant to
organisation
Harder to block certain websites
Easier to block certain websites
Can be access if have ISP account
Requires password and ID
Public access - can be accessed
anywhere
Private access - can only be accessed from
access points/certain computers
Harder for protection against viruses
Have firewall so gives some protection against
hackers
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LivingLegend - MsHana
4. Networks and the effects of using them
Why intranet?
● Safer - less chance of virus/hacking
● Can prevent external links
● Company can ensure that the information is all relevant
● Can send messages within company easily
● Better bandwidth
Local Area Networks (LANs):
● A private Local Area Network that covers a small area/one building and belongs to an
organisation/business
● Example: School network
Advantages:
Disadvantages:
Resources shared easily
Viruses spread quickly
Ease of communication between users
Printing queues
Faster transmission of data
Initial cost of setting LAN up is high - need to
buy cables, equipment etc...
Network administrator can control and
monitor
Slow internet connections
Wide Area Networks (WANs):
● A Wide Area Network that covers a large geographical area/worldwide and consists
of connected LANs.
● Example: Internet
Advantages:
Disadvantages:
Can be connected across wide areas
Greater security issues
Share files over large areas
Easy to accidentally download viruses from
WAN
Slower data transfer rate
Difficult to monitor
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LivingLegend - MsHana
4. Networks and the effects of using them
Wireless Local Area Network (WLANs):
● Wireless Local Area Network that uses wireless technology to transmit data. It uses
Wireless Access Points (WAPs) that are connected to a wired network at fixed
locations.
Advantages:
Disadvantages:
Physically safer - no loose cables
Security issue - anyone with wireless
enabled device can access the network
Cheaper - don't need to buy cables
Wireless signals are unreliable - can suffer
from interference with other radio signals
Computers and devices can access
resources from anywhere within the range of
the access points
Slower data transfer rate than LAN
Adding new computers and devices is easy
Accessing the internet using different devices:
Advantages
Laptop computers
●
●
●
Desktop computers ●
●
●
●
●
Tablets
●
●
More portable than desktops
but less portable than tablets
and smartphones
Keyboard/touchpad easier to
use than mobile phones
Safer - won't trip over loose
cables
Disadvantages
●
●
●
●
Screen size not as large as
desktops
Slower access speeds
than desktops - processors
not that powerful
Have to be in range of
network point
Limited Battery life - needs
recharging
More powerful processors
Full-sized keyboard and
mouse
Larger screen size
Wired system - more stable
internet connection
Better heat dispersion rate
●
Not portable
Portable
Larger screen than
smartphones
●
Larger and less portable
than smartphones
Use Wi-Fi - less reliable
internet connection
Smaller screen
On-screen keyboard harder
to use
●
●
●
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LivingLegend - MsHana
4. Networks and the effects of using them
Smartphones
●
●
●
●
Most portable
More likely to have mobile
phone with you
Easier to use mobile phone on
the move
Access internet from greater
places
●
●
●
●
●
Keyboard on mobile phone
is difficult to type
Smaller display
May not be able to access
certain sites
Some sites do not have full
facilities for mobile phones
Use Wi-Fi - less reliable
internet connection
4.2 network issues and communication:
Security issues surrounding the use of computer networks:
● Hacking
● Phishing
● Pharming
● Viruses
● Data can be deleted, edited, corrupted or replicated.
Should the internet be policed?
Yes
●
●
●
●
●
No
Prevent illegal material being posted
Prevent porngraphy for minors
Ensure copyright laws are enforced
Prevent children/vulnerable people
from being exposed to undesirable
websites
Help stop incorrect information from
being posted onto websites
●
●
●
●
Unsuitable materials easily available
in many other ways
Expensive to ‘police’ all websites
Difficult to enforce rules and
regulations on a global scale
Go against freedom of information
Methods for avoiding password interception:
● Running anti-spyware software
● Change passwords regularly
● Passwords should not be easy to guess or break
○ Strong passwords (e.g. Sy12@%TY965k=*) contain:
■ At least one capital letter
■ At least one number
■ At least one special character
○ Weak passwords - easy to guess (e.g. qwerty) contains::
■ Few characters
■ All letters OR All numbers
■ Relates to users
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LivingLegend - MsHana
4. Networks and the effects of using them
Authentication Techniques:
Technique
Description
Biometrics
●
●
●
●
Relies on certain unique characteristics of human beings
Examples: Retina scans, Face scans, Iris scans
Nearly impossible to forge
More expensive
Retina Scans
●
●
●
Use retina scanners to detect retina pattern
Very accurate
Wearing contact lens can stop retina scans from working
Iris Scans
●
●
Use digital camera to record image of iris
High quality images of ‘iris’ can fool the system
Magnetic Stripe
●
●
Magnetic stripe made of tiny magnetic particles on plastic film
Read by swiping through card reader
ID cards
●
Some use holographic image (hologram) to make forgery
more difficult
Passports
●
Contains RFID tags, photograph and a holographic image
Other Physical Tokens
●
Using physical objects for authentication
Virus - A program that copies itself automatically and can cause damage to data or cause
the computer to run slowly
Viruses Can:
● Delete/corrupt data
● Fill up disk space
● System files can be corrupted if on hard disk
How the computer is infected with a virus:
● Open spam email and downloaded attachments
● Running software without being checked by up to date anti-virus
● Sharing a portable medium
Methods to avoid Viruses:
● Antivirus Software:
○ Check software or files before they are run
○ Compares virus coding with database
○ Asks user’s permission to delete files with potential viruses
○ Quarantines infected files and clean them
○ Full system checks carried out once per week
● Only open email attachments from trusted sources
● Keep anti-virus software up to date
● Do not use unknown storage medias to transfer data
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LivingLegend - MsHana
4. Networks and the effects of using them
Encryption: Process of scrambling and encoding data so that the data is not
understandable. It protects sensitive data from being understood if it falls into the wrong
hands. It requires an encryption key to encrypt and a decryption key to decrypt.
Uses of Encryption:
● Protect sensitive data
● Prevents hackers from understanding the data
● Secures data being transferred from computer to computer
● Online banking
Principles of a typical Data Protection Act:
1. Data must be fairly and lawfully processed
2. Data can only be processed for the stated purpose
3. Data must be adequate, relevant and not excessive
4. Data must be accurate
5. Data must not be kept longer than necessary
6. Data must be processed in accordance with the data subject’s rights
7. Data must be kept secure
8. Data must not be transferred to another country unless they also have adequate
protection.
Network communication:
Facsimile communication:
Physical Faxing:
● Does not require use of network
● Document is scanned and the modem converts data into sound
so sent across the telephone line.
● Document is printed at the receiving end
● Requires the number of the recipient to be dialled before the
document is copied and then sent electronically
Electronic Faxing:
● Requires network (e.g. internet)
Email communication:
● Useful for sending attachments (e.g. documents, videos, music etc…)
● Can be sent and received from any device connected to the internet
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LivingLegend - MsHana
4. Networks and the effects of using them
Advantages
Traditional
Faxes
●
●
Disadvantages
Signatures on faxes are accepted
legally
Physical copy
●
●
●
●
Email
●
●
●
●
●
●
●
More secure than faxes (password
protected)
Reduced costs
Better quality document
Document received can be modified
Can be sent and received from any
devices that is connected to an
internet
Easier to send to multiple recipients
People are more likely to have access
to email accounts than fax machines.
●
●
More likely to be intercepted
Poor print quality
If telephone line is busy, can
have a delay in sending the fax
Slow process if several
documents need to be sent
Unwanted emails (spam)
Viruses can be downloaded
Video-conferencing:
● Method of visual and audio communication between people at separate locations
● Substitute for face to face conferences
● Carried out in real time
● Hardware used:
○ Webcams - input faces of participants
○ Large monitors - output faces of participants
○ Microphones - input voices of participants
○ Speakers - output voices of participants
● Software used:
○ Webcam and microphone software drivers
○ Echo cancellation software
Advantages
●
●
●
Possible to hold conferences at
short notice
Not travelling physically so
reduces costs (transport,
hotel)
People in own buildings - can
access important documents
Disadvantages
●
●
●
●
●
●
●
Time lag and lip sync problems
Jerking images due to poor internet
connection
Expensive to set up
Problems with different time zones
People need to be trained to use the system
Whole system relies on internet connection
May not be able to communicate effectively
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LivingLegend - MsHana
4. Networks and the effects of using them
Audio-conferencing:
● Refers to meetings held between people using audio (sound) equipment (e.g phone,
computer)
● Can be done over telephone network (phone conference)
● Uses Voice Over Internet Protocol (VOIP) to allow communication using voice, instant
messaging and video.
● Organiser is given a unique PIN to be shared to participants where they dial the
conference phone number and enter the PIN to join.
Web-conferencing:
● Uses internet to permit conferencing to take place
● Carried out in real time
● Uses:
○ Business meetings
○ Presentations
○ Online education or training
● Equipment:
○ Computer
○ Stable internet connection
● Links to video conferencing and audio conferencing through use of webcams,
microphones and speakers.
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LivingLegend - MsHana
5. The Effects of using IT
5.1 The effects of IT on employment:
Positive Effects of IT on employment
●
●
Increase in employment
○ Website designers
○ Computer programmers
○ Delivery drivers in retail stores
○ Network managers
Introduction of robots in manufacturing
industry creates a safer working
environment
Negative Effects of IT on employment
●
●
●
●
Advantages of using robots over humans
●
●
●
●
●
●
●
●
●
Higher productivity
Don’t go on strikes
Safer/cleaner environment
Can work in hazardous environments
Don’t get bored by repetitive tasks
More consistent results - more
accurate
Can lift heavy loads
Do not require wages so cheaper in
long run
Can work without breaks
Reduction of employment in offices as
workers’ jobs have been replaced by
computers (robots):
○ Payroll workers
○ Typing pools
○ Car production workers
Office work is being reduced due to word
processors, spreadsheets and
databases.
Robots replace jobs in manufacturing
industry
More high street jobs closing down
because of more online shops.
Disadvantages of using robots over humans
●
●
●
●
●
●
Unemployment
Expensive start up costs
Maintenance/repair costs are expensive
Need to be programmed
Reprogramming takes time and is
expensive
Increased redundancy payments
5.2 effects of IT on working patterns within organisations:
Use of technology led to increased numbers of workers changing working patterns:
● Part-time working
● Flexible hours
● Job sharing
● Compressed hours
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LivingLegend - MsHana
5. The Effects of using IT
Working Pattern
Description
Part-time working
●
Work fewer hours per week than full-time staff
Flexible hours
●
●
Any working schedule outside the traditional working pattern.
Ability to choose the start and finish times but must complete a
day’s worth of work
Job sharing
●
Full-time job is divided between two part-time workers
Compressed hours
●
An employee works full hours for the whole week but works fewer
days.
5.3 Microprocessor-controlled devices in the home:
Positive effects of microprocessors
●
●
●
●
●
●
●
●
Increased leisure time
Do not need to be in house when food
is cooking/clothes are washing
Microprocessor-controlled devices do
most of housework
Do not need to do things manually
Greater social interaction/family time
More time to go out
Microprocessor-controlled burglar
alarms provides a sense of security
Smart fridges can lead to healthier
lifestyle
Negative effects of microprocessors
●
●
●
●
●
●
Lack of exercise
Unhealthy lifestyle due to reliance
on labour-saving devices (e.g.
ready-made meals)
Laziness
Manual household skills lost
Danger of devices that use internet as
can have security issues
If the internet crashes, the device
cannot operate.
5.4 potential health problems related to the prolonged use of IT equipment:
Health RIsk
Ways to eliminate/minimise risk
Repetitive Strain Injury (RSI):
● Damage to fingers/wrists caused by
continuous use of keyboard or
repetitively clicking mouse buttons
●
●
●
●
●
Ensure correct posture
Use wrist rest
Take regular breaks
Use ergonomic keyboards
Stretching exercises
Back problems:
● Caused by sitting in front a computer
screen for a long time/all day
●
●
●
●
Use fully adjustable chairs
Use foot rests
Use screens that can be tilted
Taking breaks
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LivingLegend - MsHana
5. The Effects of using IT
Eye problems:
● Caused by continuous staring at a
computer screen for a long time or
having incorrect lighting in a room.
●
●
●
●
●
●
●
Ensure there is no screen flicker
Change to LCD screens instead of
CRT monitors.
Take regular breaks
Use anti-glare screens
Test eyes on regular basis
Use blue-screen technology
Make sure screen is at eye level
Headaches:
● Caused by incorrect lighting, screen
reflections, flickering screens etc...
●
●
●
Use anti-glare screen
Have regular breaks
Have eyes tested regularly
36
LivingLegend - MsHana
6. ICT Applications
6.1 communication applications
Communication applications:
● Newsletters
● Websites
● Multimedia presentations
● Music Scores
● Cartoon
● Flyers and posters
Uses of smartphones for communication:
● Text messaging
● Phone calls
● Accessing the internet
Internet Telephony: Type of communication technology that allows users to have a telephone
conversation via the internet
● Example: Voice Over Internet Protocol (VoIP)
○ Technology that enables people to use the Internet to make telephone calls
○ Sends voice data in packets using IP
○ Hardware needed: Microphone, speakers, headphones
Publicity and corporate image publications:
● Business cards
● Letterheads
● Flyers and brochures
6.2 Data handling applications:
Data handling application
Description/uses
Surveys
●
Information collected can be held in databases to
analyse and query it easily
Address Lists
●
Information (name, contact address, phone no.) are held
in address lists
Clubs and Society
records
●
Information (contact details, names, membership no.)
are held on databases
School reports
●
Held on databases so it can be accessed by parents
and teachers and printed reports can be made.
School Libraries
●
Information (available books for borrowing, members’
data) are held in databases.
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LivingLegend - MsHana
6. ICT Applications
6.3 Measurement Applications:
Measurement: monitoring of physical variables WITHOUT the microprocessor taking action
Examples of Measurement Applications:
● Scientific Experiments
○ Measure temperature using a data-logging system
● Weather Stations
○ Use a variety of sensors to measure: rainfall, temperature, wind speed, wind
direction, air pressure and humidity
○ Used by weather forecasters to predict the weather
Analogue Data
●
●
●
●
Data is constantly varying and has
no discrete values
Data collected from sensors is
analogue
Digital Data
●
●
Discrete data which is made up from
the binary values 0 and 1
Computers can only understand
digital data
Data from sensors is analogue data so they are sent to an Analogue to Digital
Converter (ADC) to turn the data into digital format as microprocessors and
computers only understand digital data.
When controlling devices, data from the computer needs to be converted into analogue
form using a Digital to Analogue Converted (DAC).
Use of microprocessors and computers:
● Pollution monitoring
○ Sensor (e.g. light, temp, pH, O2, CO2) placed in 2 different locations so can
compare the level of pollution
○ Data from sensor is converted to a digital form using an ADC
○ Data is sent to the computer which receives it and automatically produced
graphs
○ Data from sensor compared to pre-set value
○ Computer is connected to a mobile phone network and transmits data to
monitoring stations.
● Intensive care units in hospitals
○ Sensors read key vital signs: pulse rate, heart rate, temperature, blood
pressure, rate of respiration, glucose concentration
○ Data from sensor is converted to a digital form using and ADC
○ Data is stored in the computer’s memory
○ Computer compares data from sensors with values stored in its memory
○ An alarm is activated when the data is outside the limits of acceptability
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LivingLegend - MsHana
6. ICT Applications
Using computers in measurement
Advantages
●
●
●
●
●
●
●
●
More frequent readings
Wont forget to obtain readings
Faster response time
Employees can carry out other tasks using that time
Can give data 24/7
More accurate readings
Safer as process of measuring using humans could
be dangerous
Fewer staff needed = lower costs.
Disadvantages
●
●
●
●
Cannot respond to
unusual
circumstances
Expensive to set up
initially
Students may rely too
much on computers
IF malfunction,
computer cannot be
used
6.4 Microprocessors in Control Applications:
Microprocessor: an electronic circuit or chip that can process data, perform calculations
and act upon the results by issuing instructions.
● Found in CPUs of all computers and devices
Control: when the microprocessor takes action depending on sensor readings
Role of Microprocessor in Control Applications:
● Sensor readings are compared to pre-set value entered by the user
● If sensor reading is too high or too low, signals are sent to an actuator to change the
physical conditions
General Procedure:
● Microprocessor is programmed with pre-set values. It continually monitors the (name the
sensor in the exam) sensors, which sends data readings to an ADC, which sends a
digital signal to the computer. The reading will be compared to the pre-set value and if it
is too high or too low, a signal will be sent to the DAC and output devices called
actuators and suitable procedures (name them in the exam) will be carried out. This
process will continue to repeat until suitable conditions are obtained.
Computer control in Applications:
● Turtle graphics
● Automatic Washing Machines
● Automatic cookers
● Computer controlled central heating systems
● Burglar alarms
● Computer controlled glasshouses
39
LivingLegend - MsHana
6. ICT Applications
Sensors:
Sensor type
Possible Applications
Temperature
●
●
●
●
●
Central heating systems
Chemical processes
Glasshouses
Washing Machines
Automatic cookers
Moisture
●
Glasshouses
Oxygen/Carbon
Dioxide
●
●
Glasshouses
Environment monitoring
Light
●
●
●
Glasshouses
Automatic doors
Photography
Infra-red
●
●
Intruder alarms
Counting items
Pressure
●
Intruder alarms
Acoustic
●
●
Sound
Check for blockages in pipes
Motion
●
Detect movement
pH
●
●
●
Pollution monitoring
Glasshouses
Chemical processes
6.5 Modelling Applications
Uses:
●
●
●
●
Stimulate scenarios to work out the possible outcomes
Predict outcomes based on the inputs
Training (ex. Surgeons, pilots)
Design (ex. Architects produce 3D model of building)
Examples of modelling applications:
● Spreadsheets - personal finance
● Pilot simulation
● Weather forecast models
● Building simulation
● Traffic control
● Car driving simulations
● Large scale chemical experiments
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6. ICT Applications
Advantages
●
●
●
●
●
Disadvantages
Cheaper as the real thing doesn't
need to be built
Safer to run a computer model as real
life situations may be hazardous
Saves time - smaller time scale
Can introduce a greater variety of
situations (e.g. extreme weather)
Save materials
●
●
●
●
Accuracy - cannot perfectly mimic
real life situation
High Initial cost
Programming error
Workers need to be trained to use the
system
6.6 Applications in Manufacturing Industries:
Robots in Manufacture and production line control:
● Used in manufacturing industries to:
○ Lift heavy objects
○ Assemble parts together
○ Paint/spray items
○ Manufacturing of microchips
● Robots are programmed to carry out the task
● Robots are equipped with sensors to detect
changes in the environment
● Good at repetitive tasks
Computer controlled systems (Robots):
Advantages
●
●
●
●
●
●
●
●
●
Higher productivity
Don’t go on strikes
Safer/cleaner environment
Can work in hazardous environments
Don’t get bored by repetitive tasks
More consistent results - more
accurate
Can lift heavy loads
Do not require wages so cheaper in
long run
Can work without breaks
Disadvantages
●
●
●
●
●
●
Unemployment
Expensive start up costs
Maintenance/repair costs are
expensive
Need to be programmed
Reprogramming takes time and is
expensive
Increased redundancy payments
6.7 School Management Systems:
School Management Tasks:
● Manage learner registration and attendance
● Record learner performance
● Organising Examinations
● Creating timetables
● Managing teaching cover/substitution
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6. ICT Applications
Managing learner registration and attendance:
● Can use an ID card containing a magnetic stripe on the back of the card and swipe
through a magnetic card reader when entering and leaving school to identify the
student name, time and date.
● System records time of arrival and sends data to administration database
● If student arrives after a certain time, student flagged as late
● Letters are sent automatically to parents if late
Recording learner performance:
● Use spreadsheets to monitor the student’s performance
● Can import data into a report to summarise the student’s performance
Timetables used for:
● Organising examinations
● Creating student and staff timetables
● Managing teacher cover/substitutions
6.8 Booking Systems:
Areas where booking systems are used:
● Travel industry
● Theatres
● Cinemas
Online processing involved in booking tickets:
● Customers clicks on type of ticket they would like to buy
● Date, time, and required number of seats is entered
● A seating display of the theatre is shown and the user selects the seat(s) they want
and clicks CONFIRM
● Database is searched to check the availability of the selected seat(s)
○ If seat is available, total price and seat numbers are shown
■ If customer is happy, they will select CONFIRMED and the seats are no
temporarily set at NO LONGER AVAILABLE
■ Customers enter their personal information
■ Payment method is selected and payment is made
■ Final details shown and email is sent to customer (e-ticket)
■ Database updated and seats are no longer available
○ If seat not available, customer has to choose another option
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6. ICT Applications
Online Booking Systems:
Advantages
●
●
●
●
●
●
Disadvantages
Prevent double-booking
Customer gets immediate
feedback on where seat is
available/taken
Can make bookings
anytime/24/7
Customer’s email address
allows the booking customer to
advertise special offers to them
E-tickets reduces chance of
ticket being lost
Data is updated immediately
●
●
●
●
●
●
●
Expensive set up and maintenance
Need access to a computer and a reliable
internet connection
If websites poorly designed, can be
difficult to book
Doesn’t allow customers to build a
personal relationship with the travel
agent.
Requires a credit/debit card to make
payments online
Requires an email address
Easier to make mistakes when booking
6.9 Banking Applications:
6.9 Banking Applications past paper questions
EFT (Electronic Fund Transfer): System that allows money transfer instructions (from
banks/businesses) to be sent directly to a bank’s computer system.
Uses of EFT:
● Large businesses pay the employee’s
salaries
Automatic Teller Machine (ATMs):
Used for:
● Withdrawing cash
● Depositing cash or cheques
● Checking account balance
● Money transfers
Customer inserts bank card into ATM
Bank card read by magnetic stripe reader
Card is checked if valid
Customer is asked which currency/language they require
Customer is asked to enter PIN using the numeric keypad
ATM compares typed PIN with stored PIN in the chip.
a. If same, transaction proceeds,
b. If the PIN is incorrect, the customer is asked to reenter the PIN. If three failed
attempts customer’s card is withheld and transaction is rejected
7. Customer is asked which service they require and they select an option (to take cash)
8. Customer enters amount to withdraw
9. Amount checked against card limit
10. Customer asked if they want a receipt
11. Card is returned and money is dispersed
1.
2.
3.
4.
5.
6.
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6. ICT Applications
Credit/debit card transactions:
Debit Card
What is it? How does it
work?
What information is
contained in the card?
What is the difference
between them
Debit cards draw money
directly from your checking
account when you make the
purchase.
●
●
●
●
●
●
Credit Card
A credit card allows you to
borrow money against the
card’s credit limit
Card number
Cardholder name
Expiration date
Magnetic stripe
Hologram
Signature
Debit cards do not have interest but credit cards charge
interest.
Processing involved in credit/debit card transactions:
1. PIN is entered using keypad
2. Card is checked to see if it’s valid (expiry date, correct owner, etc)
3. PIN is read from chip on card and compared to the one that’s been keyed in
a. If they match then transaction may continue
b. If incorrect a maximum of three attempts before the transaction is terminated
4. Restaurant’s bank contacts customer’s bank
a. Check is made if they have enough funds
b. If card not valid/ not enough funds then transaction
is cancelled
5. If everything is OK then transaction is authorised
6. Price of meal/item is then deducted from customer’s
account
7. Same amount is added to restaurant’s bank account
8. A receipt is produced as evidence of purchase
Clearing of cheques:
1. Check sent to clearing centre where checks are
sorted and cheque data is created
2. Amount is read using OCR
3. Cheque data is written in special magnetic ink
and passed through the MICR reader where the
cheque number/amount/bank code is read
4. Cheques sorted by sort code
5. Check data electronically sent to payer’s bank
6. Payers bank checks for fraud and checks if there are sufficient funds
7. If funds are available, money is sent to receiver’s bank where it is deposited in the
receiver’s bank account
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6. ICT Applications
Contactless Cards:
● Use RFID Technology
● Have a small chip that emits radio waves so when the card is held near a terminal,
the terminal picks up the waves and processes the transaction
Phone Banking
1. The person calls the bank
2. Enter their account number using the phone’s number keys
3. Enter PIN
4. Hear various options and they pick one option
Uses: check balance, pay bills, transfer money using EFT, get financial advice
Advantages
●
●
Disadvantages
No need for computer
Can speak to actual person
●
●
System is difficult to use
Slower and longer queues
Internet Banking:
● Customers use a computer to connect to a bank’s secure encrypted website where
they login
● Uses: check balance, pay bills, transfer money using EFT, apply for loans
Advantages
●
●
●
●
Disadvantages
More convenient because 24/7
Save travel time and transport cost
Data can be downloaded and
analysed
People find it embarrassing to ask for
a loan face to face
●
●
●
●
Requires computer and internet
access
Some people prefer face to face
conversations
If an account is hacked (password
and username stolen), money can be
stolen.
Easier to make errors with online
banking
6.10 Computers in Medicine:
Contents of information systems in Medicine:
● Patient records
● Pharmacy records
● Monitoring and expert systems for diagnosis
Medical aids that 3D printers produce:
● Surgical and diagnostic aids
● Development of prosthetics and medical products
● Tissue engineering
● Artificial blood vessels
● Design of medical tools and equipment
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6. ICT Applications
6.11 Computers in Libraries:
Files used in libraries:
● Barcode on the books being borrowed
● Barcodes of the borrower’s library card
Processing involved in the issue of books:
1. Barcode of book is scanned by barcode scanner
2. System automatically calculates the due back date
3. Borrower’s library card’s barcode is scanned
4. Searches book code in books table until matching record is found
5. Flag the book as ‘borrowed’
6. Book file is linked to the borrower’s file and both files are updated to record which books
are borrowed and when it is dued back
7. Date of book due back is saved in the borrower’s file and a reminder is sent if the due
date is exceeded
Automatic processing involved in issuing reminders for overdue books:
1. Computer reads record from book file
2. Corresponding record read from borrower’s file
3. Compares due date with current date
4. The borrower’s details are found and letter/email automatically sent out
5. Next record in book file read
6. Repeats until whole file have been checked
6.12 Expert Systems:
Applications that use expert systems:
● Mineral Prospecting
● Car Engine fault diagnosis
● Medical diagnosis
● Chess games
Components of an expert system:
● Interactive user interface
● Inference engine
● Rules base
● Knowledge base (uses knowledge from experts)
How an expert system is used to suggest diagnoses:
1. An interactive user screen generates often multiple choice/yes or no questions
2. System asks questions related to diagnosis
3. Operator types in answers to questions
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6. ICT Applications
4. System asks questions based on previous response input by the operator
5. Inference engine compares answers to questions with facts stored in knowledge base
using the rules base
6. System suggests possible diagnosis
7. Explanation system will explain how the expert system arrived at its conclusion
8. Expert system shows predictions and conclusions
Advantages of using expert systems
●
●
●
●
●
●
Disadvantages of using expert systems
Provide more consistent answers
Give number of different possibilities
Reduced cost of finding a solution
because less need for specialists
Can be used online/24/7
Collective wisdom of more than one
expert
Do not forget to ask a question
●
●
●
●
Machines lack common sense
Expensive to maintain
Expensive to set up
If knowledge base contains errors,
incorrect decisions may be made
6.13 Computers in the Retail Industry:
Point of Sale (POS):
● Place where you pay for purchases
Includes:
● Barcode scanner
● EFTPOS
● System to update the stock-level of the good
● Producing receipts
How the stock file is updated automatically at POS terminals:
1. Barcode of each item is scanned using a barcode scanner
2. Barcode searched for on the stock file until match is found
3. Price and product description is sent to EPOS
4. Stock level in the record is reduced by 1
a. If stock level is less than or equal to reorder minimum level of stock, computer
automatically orders a batch of items from the supplier
b. Once order purchased, item is flagged on file to prevent reordering
c. When new goods arrive, the barcodes will be used to update the stock files
and item will be unflagged
5. Repeated until all items have been scanned
6. Customers are given a bill with prices of their purchase.
Electronic Fund Transfer at Point-of-Sale (EFTPOS)
1. Customer gives bank card to the cashier
2. Cashier runs the card through a card reader (+ customer enters a PIN)
3. Reader checks if amount to be paid is less than contactless limit
4. Card is checked if it is valid
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6. ICT Applications
5.
6.
7.
8.
9.
a. If valid, transaction continues
b. If not valid, transaction is terminated
PIN is read from chip on card and compared to one typed in
An authorisation code is sent to cashier
Cashier confirms the purchase and sends an EFT message to the bank
Bank subtracts money from customer’s account and adds money to the store
account
Cashier returns the card and receipt to the customer.
Internet shopping: Buy things online using a computer connected to the internet and some
form of electronic payment
Advantages of internet shopping
●
●
●
●
●
●
Reducing travel costs
Wastes less time as no need to travel
Users have access to worldwide
markets - greater variety of products
that may be cheaper
Disabled/elderly can access any shop at
home
Can be done 24/7
Shops save money as less staff needed
Disadvantages of internet shopping
●
●
●
●
●
●
Lack of socialisation
Health risks due to lack of exercise
Security issues (phishing, hacking,
pharming etc…)
Accidentally using fraudulent shopping
websites has a risk of security issues
Can only see a picture of goods (colour
may differ)
High street shops closing down
6.14 Recognition Systems:
Recognition systems
How they work
Magnetic Ink
Character
Recognition (MICR)
●
Optical Mark
Recognition (OMR)
●
●
●
●
System that reads characters printed in a special ink
(containing iron particles)
Characters converted into a form the computer can
understand
Device that read marks written in pen or pencil
Shines beam of light - light reflected to sensors and areas
shaded in reflect less light
Position of the mark is stored in the computer’s memory
Optical Character
Recognition (OCR)
●
Used to scan text from hardcopies and transfers them into
an editable form which can be edited in word processors
Radio Frequency
Identification Device
(RFID)
●
●
●
Uses radio waves to read and capture info stored on a tag
Tag read from a distance
RFID made from two components:
○ Microchip that stores and processes information
○ Antenna to receive and transmit data/info
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6. ICT Applications
Number Plate Recognition Systems:
1. Sensor detects vehicle and sends a signal to a microprocessor to instruct the camera
to capture image of front side of vehicle
2. Algorithm used to isolate number plate from image
3. Brightness and contrast of image is adjusted to make the number easier to read
4. Each character read and decoded using OCR
5. Number plate and time stored in database
6. Number plate compared with ones stored in database
7. Car is identified
Processing of cheques:
● MICR used to read information stored on bottom of cheques (e.g. account number,
name, date, bank account number)
Uses of OMR Media:
● School registers
● Multiple-choice examination papers
Uses of RFID technology:
● Tracking stock
● Passports
● Automobiles
● Contactless payments
6.15 Monitoring and tracking systems:
How a workforce or member of public can be monitored/logged:
● Ankle monitor uses RFID by inserting microchip into device strapped to ankle
● GPS monitoring
● CCTV cameras
Cookies: Small look-up table containing pairs of values that stores the user’s browsing
preferences and creates an anonymous user profile.
Key-logging: Software used to monitor each key press on a user’s computer (may be used by
hackers to obtain personal details)
How worker/employee call monitors can be used?
● Employee call monitoring allows managers to listen in to employee’s telephone calls to
improve the employee’s performance, used as training tool and monitor calls for
companies who are concerned with security
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6. ICT Applications
6.16 Satellite Systems:
Satellite systems
Uses
Global Positioning Systems (GPS)
Used to find exact location of a transport using
satellite navigation systems
Used in cars and lorries to calculate routes
Geographical Information
systems (GIS)
Computer system that allows potential locations to be
analysed based on specific querries
How does GPS display location:
1. At least three satellites are used to transmit radio signals to earth
2. Software in smartwatch/phone/any device interpret signals
3. Triangulation takes place
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7. The Systems Life Cycle
Purpose of system analysts:
● Review an existing system and suggest a number of improvements to design a new
system that can carry out the same tasks better.
Main Stages: (ADDIDE)
1. Analysis
2. Design
3. Development and Testing
4. Implementation
5. Documentation
6. Evaluation
7.1 Analysis:
Analysis stage: where the current system is looked at in detail in order to figure the changes
needed to make the system better
● Research and collect data about current system
● Identify the inputs, processing and outputs of the current system
● Identify problems with current system
● Identify user and information requirements for the new system
● Identify suitable hardware and software for the new system
● Produce a cost-benefit analysis
Methods of researching an existing system:
Method
Description
Observations
Systems analyst
sits and watches
somebody using
the current system.
Interviews
Questionnaires
One to one
question and
answer session
between analyst
and employee.
Distributing
questionnaires to
the users/
employees to find
out about their
views on the
current system.
Advantages
●
●
●
●
●
●
●
●
●
●
●
Disadvantages
Analyst obtains reliable data
Better overall view of the
system
Cheap
●
People can be
uncomfortable being
watched and may work
differently (Hawthorne
effect)
User is more open and honest
about answers
Questions can be modified and
extended
Can observe facial expression
and body language
●
Time consuming to
complete all interviews
Expensive as time needed
Not anonymous
Can give answer that they
think the interviewers want
Faster to complete all
questionnaires
Cheaper than interview
Individuals can remain
anonymous so more trustful
More people can answer
questionnaire than interview
Can fill it in in their own time
●
●
●
●
●
●
●
●
Not popular with users
Too inflexible so no follow
up questions
Users tend to exaggerate
responses if anonymous
As anonymous, may not
take it seriously
Cannot expand answers
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7. The Systems Life Cycle
Examination of
existing
documents
Look at paperwork
and files to allow
analysts to analyse
the operating
instructions,
training manuals
etc...
●
●
Information can be obtained
that is not available for other
methods
Can see the scale of the
problem easily
●
●
Time consuming to go
through all the documents
Expensive as time needed
Recording and analysing information about the current system:
Describe the need to identify:
● Inputs, outputs and processing of the current system
○ New system need to deal with similar inputs and outputs and processes
● Problems with the current system
○ To improve it in the new system to run more smoothly and efficiently
● User and information requirements for the new system
○ Need to make a list of requirements for the new system so the new system can
be designed to meet these requirements
System Specification:
● Hardware:
○ Number of computers
○ Input and output devices
● Software:
○ Custom made or off-the-shelf software
7.2 Design:
Design stage: Where the system is planned thoroughly to make sure that the developers
know how each screen should look and how the system should look
● Design the data capture forms
● Design the screen layouts
● Design outputs in the form of screen displays and printed reports
● Produce system flowcharts
● Design validation rules
● Design file structures
● Choice of hardware/software
● Deciding on test strategies
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7. The Systems Life Cycle
Data Capture forms:
● Either paper-based or
electronic-based
● Allow data to be input to the system
Paper Based
●
●
●
●
System outputs:
● On-screen reports
● Printed report
Electronic Based
Heading and instructions
Use text boxes/tick
boxes/character boxes
Sufficient space to write answers
Clear fonts and colours
●
●
●
●
●
●
●
Use text boxes
Use on-screen help when completing the form
Use drop down/combo boxes
Automatic validation of data
Control buttons
Double entry boxes
Clear font and colours
Data Validation Routines:
Validation method
Description
Length check
Check if input data contains the required number of characters
Type check
Checks that the data doesn’t contain invalid characters
Format check
Makes sure that data is in a specific format
Presence check
Checks that data has been entered
Check digit
This is an extra digit added to a number which is calculated from
the digits.
Can identify three types of errors:
● Two digits transposed (e.g. 13597 instead of 13579)
● Incorrect digit entered twice (e.g. 13559 insead of 13579)
● Digit missed out (e.g. 1359 insead of 13579)
Data Verification Routines:
Verification methods
Visual verification
visual comparison of data entered with a data source
Double data entry
entering data twice by 2 different people and the computer
compares the two sets of data
File structure:
When building a database, the following needs to be considered:
● Field Length
● Field Name
● Data type
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7. The Systems Life Cycle
7.3 Development and Testing:
Testing Designs:
Data/File Structures:
● Determine how data is stored in a system
● Made of tables, fields, field properties and records
Validation Routines:
● Created by entering validation rules
● Tested by:
○ Enter correct data
○ Purposefully enter wrong data
Input Methods:
● Create well designed data-entry forms with form controls
● Tested by:
○ Checking whether data can be entered
Output methods:
● On-screen outputs and printed outputs
● Tested by:
○ Ensure that printed outputs can be printed
○ Checking whether the information is clear and correct
Testing Strategies:
●
●
Individual modules should be tested after created
Once the development of each module is completed, the whole system needs to be
tested as even though each module may work individually, when put together there
might be data clashes or incompatibility.
Type of data
Definition
Example
Normal
Data that is appropriate/reasonable and has
an expected outcome
Month can be any whole
number between 1 and 12.
Abnormal
Data outside the limits of acceptability or
wrong type of data that should be rejected or
cause an error message
Month cannot be negative
number, non-integer values,
numbers greater than 12.
Live
Data with known outcomes. It has been
used in the previous system/existing system.
-
Extreme
Data that is at the limits of acceptability
Extreme values for month are
1 and 12
●
Necessary to improve the system and make changes after testing.
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7. The Systems Life Cycle
7.4 Implementation:
●
●
●
Train staff
Transfer files from existing system to new system
Changeover:
○ Direct Changeover
○ Parallel Running
○ Pilot Running
○ Phased Implementation
Method of
implementation
Description
Suitable for
which
situation
Advantages
Disadvantages
Direct
Changeover
New system
introduced
immediately
Small
organisation
that can
afford to lose
data OR
need quick
changeover
●
●
Cheaper
Saves time
implementing new
system
Advantages are
intermediate
Less likely to have
malfunctions as new
system is fully tested
●
Disastrous if
new system fails
More expensive
than direct
changeover
More time
consuming than
direct changeover
Parallel
Running
Pilot Running
Phased
Implementation
●
●
Old and new systems
run side by side for a
time before new
system takes over
Organisation ●
that cannot
afford to lose
data and
●
cost is not an
issue.
If new system fails,
old system is still
available
Can gradually train
staff
●
New system
introduced to one
branch/office and its
performance is
assessed before
introduced to other
areas of the company
Organisation
where there
are clearly
definite
separate
processes
●
Only affects certain
branch if system
goes wrong
Faster and cheaper
than parallel
running
●
Only one part of the
new system is
introduced and once
works satisfactorily, the
next part is introduced
and so on until the old
system is fully
replaced.
Organisation
where there
are several
branches
doing same
work
●
If new system fails,
most of old system is
still available
Can see if part of
new system works
before proceeding
Can gradually train
staff
●
●
●
●
●
●
●
More expensive
than direct
changeover
More time
consuming than
direct changeover
More expensive
than direct
changeover
More time
consuming than
direct changeover
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7. The Systems Life Cycle
7.5 Documentation:
Technical Documentation:
● Needed to help programmers/analysts to:
○ Make improvements to the system
○ Make repairs to the system
○ Maintain the system
● Components:
○ Purpose of the system/program
○ Limitations of the system
○ Hardware and software requirements
○ Sample runs/test runs
○ Input format
○ Output format
○ Program listing
○ Program language
○ Program flowcharts/algorithms
○ System flowcharts
○ File structure
○ List of variables
○ Validation routines
User Documentation:
● Needed to:
○ Help users to learn how to use the software/system
○ Help users to overcome problems
● Components:
○ Purpose of the system
○ Limitations of the system
○ Hardware and software requirements
○ Sample runs
○ Input format
○ Output format
○ How to load/run/install software
○ How to save a file
○ How to print data
○ How to add records
○ How to delete/edit records
○ Error messages
○ Error handling
○ Troubleshooting guide/helpline
○ Frequently asked questions
○ Glossary of terms
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7. The Systems Life Cycle
7.6 Evaluation:
How should the solution be evaluated on?
● The efficiency of the solution
● The ease of use of the solution
● The appropriateness of the solution
Evaluation strategies:
● Compare solution with original task requirements
● Identify any limitations and necessary improvements to the system
● Evaluate the user’s responses to the results of testing the system
● Analyse feedback from users
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8. Safety and Security
8.1 Physical Safety:
Common physical
safety issues
Causes
Methods of prevention
Electrocution
Spilling drinks near
computers
Use an RCB (residual current breaker)
Check insulation on wires regularly
Don't allow drinks near computers
Fire
Sockets being overloaded
Equipment overheating
Ensure good ventilation
Don't overload sockets
Don't cover equipment vents
Have carbon dioxide extinguisher nearby
Tripping wires
Trailing cables
Use cable ducts
Neatly tuck wires away
Use wireless connections when possible
Heavy equipment
falling
Heavy equipments falling
off the edge of a desk
Use strong and large desks
Place hardware at the centre of the table
Strategies to minimise potential safety risks:
● Check state of wires regularly
● Put drinks away from the computer
● Tidy wires neatly
● Don't cover computer with fabric/paper
● Don’t overload a socket
8.2 eSafety:
Personal Data: Any data concerning a living person who can be identified either from the data
itself or from the data in conjunction with other information
Why should personal data be confidential and protected?
● Prevent identity theft
● Prevent theft of money
● Prevent from harm from online predators
Examples of personal data: (*Sensitive personal data)
● Name
● Home address
● School Name
● Ethnic origin
● Medical details
● Criminal records
● Date of birth
● Banking details
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8. Safety and security
How to avoid disclosing personal data:
● Do not give out personal information to strangers online
● Do not send people photos of yourself
● Maintain privacy settings
● Online visit secure websites
● Use websites recommended by teachers
● Use learner-friendly search engines
● Be vigilant when using social networking sites
Using social networking sites/instant messaging/internet chat rooms:
● Know how to block/report unwanted users
● Never arrange to meet anyone alone
● Always telling an adult first and meeting in a public place
● Avoid misuse of images
● Always use appropriate language
● Respect people’s confidentiality
Measures taken when playing online games:
● Using nickname and never real name
Why is E-safety needed?
● Protect against identity theft, online predators, cyber attacks, cyber bullying…
Using emails:
● Only email people you know
● Think before opening email from an unknown person
● Never email school’s name or picture of learner in school uniform
8.3 security of data:
Hacking: act of gaining illegal unauthorized access to a computer system with the intention
of causing harm.
Effects of Hacking:
● Identify theft - misuse of personal data
● Data can be deleted, changed, corrupted, and used for fraudulent purposes
Measures to protect data from hackers
● Use firewall
● Use biometric data to enter the network
● Use strong passwords and ID that are frequently changed
● Use intrusion detection software
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8. Safety and Security
User id and Passwords: Method of authentication that helps improve security
Methods of minimizing the risk of passwords being misused if intercepted:
● Encrypting the password
● Use twin-factor authentication
● Changing passwords regularly
Biometric data: unique identification that relies on certain unique characteristics of human
beings - used to improve security
Digital certificate: A pair of files stored on the user’s computer that allows
people/organisation/computers to exchange secure information over the internet
Pair of files include:
● Public key - known by anyone
● Private key - known by the computer user
Digital certificates include:
● Sender’s email address
● Name of digital certificate owner
● Serial number
● Expiry date
● Digital signature for certificate authority
Secure Socket Layer (SSL): a type of protocol that allows data to be sent and received
securely over the internet
Features of a webpage that identify it as a secure server:
● Website URL contains https
● Small padlock in the status bar
Phishing: A fraudster sends out legitimate-looking emails to target users that appear to come
from a trusted source (authentic). They are lured to click on a fake website and enter their
personal details.
Methods of preventing Phishing:
● Filter out phishing emails
● Users should be cautious when opening emails or attachments
● Dont click on executable attachments ending in .exe, .bat, .com etc...
Pharming: A malicious code installed on a user’s computer or on a web server and the code
will redirect the user to a fake website without their knowledge that looks authentic but
belongs to the fraudster It is used to obtain the user’s personal details.
Methods of preventing Pharming:
● Use up-to-date anti-spyware software
● Keep DNS serve up to date
● Use up-to-date firewall services
● Users should be cautious and look out for clues they are redirected to a fake website.
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8. Safety and security
Smishing: SMS phishing where creators use SMS systems on mobile phones to send out
fake messages that often contain an URL or telephone number embedded in the text.
Methods of preventing Smishing:
● Double check message for spelling/grammatical errors
● Check link to see if it is legitimate
● Never reply to messages from unknown senders
● Users should be cautious when receiving suspicious messages
Vishing: voice mail phishing that uses a voice mail message to trick the user into calling the
telephone number contained in the message.
Malicious use of technology (phishing, pharming, smishing) to collect personal data can lead to
identity theft
How to recognise if someone is attempting to obtain personal data:
● Conveys a sense of urgency
● If it is too good to be true, it is probably fake
How to report if suspecting someone has obtained your personal information:
● Contact the bank immediately
Moderated forms
Unmoderated forms
Online discussion forum in which all the
posts are checked by an administrator
before posted. It prevents spam and filters
inappropriate/rude/offensive posts
Not policed and not moderated by an
administrator, e.g. the internet
Spam Emails: Electronic junk emails/unsolicited emails sent to everyone on mailing lists and
may lead to denial of services where the network slows down because of being flooded with
spam. It can also fill up the receiver’s mailbox.
Why should spam emails be protected:
● May contain viruses
● May contain spyware
● Spam fills inbox and stops other emails
Spam Prevention Techniques:
● Use up-to-date spam filter
● Block images in HTML messages as these are used in web beacons
● Do not sign up to commercial mailing lists
● Do not reply to suspicious emails
● Unsubscribe from mailing list not explicitly subscribed in the first place
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8. Safety and Security
Encryption: Process of scrambling and encoding data so that the data is not
understandable. It protects sensitive data from being understood if it falls into the wrong
hands. It requires an encryption key to encrypt and a decryption key to decrypt.
Computer virus: A piece of program code that replicates itself automatically and can fill up
hard disk space and cause damage to data or cause the computer to run slowly
Viruses Can:
● Delete/corrupt data
● Fill up disk space
● System files can be corrupted if on hard disk
Effects of infecting a computer with a virus from a downloaded file:
● Cause the computer to ‘crash’ and become unresponsive
● Software can delete files/data on the computer
● Software may corrupt operating system files
Preventative actions to avoid computer viruses from downloaded files:
● Install up-to-date anti-virus software
● Don't download softwares from unknown sources
● Don't download email attachments from unknown senders
How to be subject to online credit card fraud:
● Hackers gaining access through spyware, phishing, pharming where user is tricked into
giving personal and financial details
● Breaking of passwords
● User visiting a fake website and entering personal and financial details.
● Using internet access without password control
● Logging into an account or website in a public place
Cloud: An online storage medium used to backup files and can be accessed anywhere with
internet connection
Issues related to cloud security:
● People transferring confidential data to a cloud service provider have risk of data being
hacked → lead to loss or corruption of data
● Celebrity data had been hacked and images had been shared online
Firewall: Can be software or hardware and it sits between the user’s computer and an
external network and filters information coming in and out of the user's computer.
Tasks carried out by a firewall:
● Monitors and controls ‘traffic’ between user’s computer and public network (internet)
● Checks where incoming/outgoing data meets the criteria
● Gives user security warning when data fails the criteria
● Log all incoming/outgoing traffic
● Keep list of all undesirable IP addresses
● Prevent access to undesirable sites
● Prevent viruses or hackers entering the user’s computer network
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9. Audience
9.1 Audience Appreciation:
Factors that should be considered when planning and creating an ICT solution:
● The age of the target group
● Experiences of the audience
● Expectations of the audience
● Knowledge of the audience
Factors that should be considered when writing a presentation:
● Language used
● Multimedia/colours used
● Length of presentation
● Interactive presentation
● Examples used
9.2 legal, moral, ethical and cultural appreciation:
ICT 9.2 Moral, ethical, legal
Why is copyright legislation is needed:
● Protect software
● Gives the author legal protection
Principles of copyright relating to computer software (e.g. software piracy)
● It is illegal to:
○ Make a software copy to sell and give away
○ Use the software on a network on multiple computers
○ Use coding from copyright software in your own software and then selling it
without permission
○ Rent out the software without permission
○ Use the name of the copyrighted software on another software
Methods used by software producers to prevent software copyright from being broken
● When software installed, the user needs to enter a unique product key
● User needs to click OK/I AGREE to license agreement
● Original software packaging has a hologram
● Software only runs when there is CD-ROM, DVD-ROM, or Memory stick in the drive
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9. Audience
What does it mean?
How is it applicable to ICT?
Legal
Ensuring that copyright laws are
followed
Not using any coding/branding
from existing software
Morality
Distinguishing between right and wrong
Setting up a fake website
Ethics
Breaking a code of conduct
Leaking information to the rival
software publisher
Culture
Ensuring that people are not offended
when the software is released to
another country with different cultures
Certain colors/designs
Computer games may mock
religious beliefs
Should the internet be policed?
Yes
●
●
●
●
●
No
Prevent illegal material being posted
Prevent porngraphy for minors
Ensure copyright laws are enforced
Prevent children/vulnerable people
from being exposed to undesirable
websites
Help stop incorrect information from
being posted onto websites
●
●
●
●
Unsuitable materials easily available
in many other ways
Expensive to ‘police’ all websites
Difficult to enforce rules and
regulations on a global scale
Go against freedom of information
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10. Communication
10.1 communication with other ICT users using email:
Constraints that affect the use of email:
Laws within a country
●
●
●
●
Emails with false/misleading subject lines should not be sent
Must have a clear way of unsubscribing
Must have a clear privacy policy
Don't allow organisations to harvest email addresses
Acceptable language
●
●
●
●
Cannot use obscene images
Cannot use abusive language
Cannot use racist language
Uses of illegal materials
Copyright
●
Emails & attachments from companies and organisations
usually contain a copyright statement
●
Respect each other’s view and display common courtesy
Local guidelines set
by an employer
The need for security
Netiquette
Rules involve:
● Checking for spelling/grammatical errors as it sets a good
impression
● Do not be abusive as this may upset people
● Do not plagiarize and follow copyright laws
● Avoid humour as some people may not understand
● Do not use capital letters to highlight comments as this can
be seen as shouting
● Don't send spam
● Respect other people’s privacy and do not discuss public
info that may embarrass
Password protection
●
Using strong passwords and change it regularly
Spam Emails: Electronic junk emails/unsolicited emails sent to everyone on mailing lists and
may lead to denial of services where the network slows down because of being flooded with
spam. It can also fill up the receiver’s mailbox.
Why must spam be prevented:
● Annoying
● Use up valuable bandwidth on the internet and slows it down
● Potential of virus attached
● Clogs up a user’s inbox
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10. Communication
Methods to prevent spam:
● Use up-to-date spam filter
● Block images in HTML messages as these are used in web beacons
● Do not sign up to commercial mailing lists
● Do not reply to suspicious emails
● Unsubscribe from mailing list not explicitly subscribed in the first place
Why are email groups used:
● Easier to send multiple emails
● Group people together for marketing purposes
● Use email groups to set up meetings to ensure that everyone is invited → prevents
forgetting
10.2 effective use of the internet:
Internet: Worldwide network of networks
Intranet: Private network that uses the same protocols as the internet, but usually confined to a
small organisation and is not available to the general public.
World wide web: part of the internet which users can access through a web browser as a
means of researching information on the internet
Cloud Storage: An online storage medium used to backup files and can be accessed anywhere
with internet connection
Internet Terms
Definition
HyperText Transfer
Protocol (HTTP)
Set of rules that must be obeyed when transferring files over the internet
HyperText Transfer
Protocol secure
variant (HTTPS)
Set of rules that must be obeyed when transferring files over the internet
Uniform Resource
Locator (URL)
A web browser that allows the user to display a webpage
Hyperlink
Allows users to navigate between web pages
Internet Service
Provider (ISP)
Company that provides internet services to users
File Transfer
Protocol (FTP)
Network protocol when transferring files from one computer to another
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10. Communication
Structure of web address:
1. Protocol (usually http or https)
2. Domain host (www)
3. Domain name (name of website)
4. Domain type (.com, .org, .gov) OR A country code (.uk, .us)
Use of a web browser:
● Allows a user to display a webpage on their computer screen
● They interpret or translate the HTML from websites and shows the result of the
translation
Uses of a search engine:
● Useful if you don’t know the URL of the website or to find information but don’t know
where to look
● They use words entered in the search
Blog: Personal internet journals where the writer will type their personal opinions on some topic
and provide links to relevant websites
Features of a blog:
● Public/anyone can see it
● Personal journal/online diary
● Owners’ observations/opinions on a topic
● Can have links to other sites
● Viewers can post comments/authors reply to comments
● Frequently updated by owner
Wiki: Software/website that allows users to add/modify/delete content and edit web pages using
any web browser. It normally uses a simplified mark-up language and is created collaboratively
with multiple users.
Features of a wiki:
● Anyone can edit, delete or modify
● Many authors
● Shows/keeps track of all entries
● Allows large documents to be seen by many people
Differences between Blogs and Wikis:
Blogs
●
●
●
●
Wikis
Single author
Usually in reverse chronological order
Personal (contains someone’s
opinion)
Can only add comments to blogs but
cannot edit them
●
●
●
●
Many authors
Has structure determined by content
and users
Usually objective
Can be edited
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10. Communication
Social Networking: Building online communities of users who share the same interests and
activities - enables people to share photos/videos/send messages and is done by creating a
public profile.
Features of social networking sites:
● Each member provided with free web space
● Each member can build their own private and public profiles
● Can upload content (photos/videos…)
● It is possible to ‘write on each other’s wall’
● Free instant messaging and video chatting
● Can email other members
● Can create pages to post photos,articles…
● Can invite people to become friends
● Can control who can access their private data
Advantages and disadvantages of social networking
Advantages
●
●
●
●
●
Increase number of worldwide friends
Real time information sharing
Easier to advertise to large groups of
people
Similar interests contact each other
Speed of news increases
Disadvantages
●
●
●
●
●
●
●
●
Reduce face to face communication
Cyber-bullying increases
Risks of frauds increases
Risks of identity theft increases
Time wasting increases
Need the internet
Need a computer/device
Addiction
Why is the internet so popular:
● Huge amount of information available
● Fast speed of accessing information
● Information is likely to be up to date
● Pages on the internet has multimedia elements
Why is an internet search to find relevant information not always fast:
● Danger of information overload
● Certain websites are always on the top but some may not contain valuable
information
Why is it not always easy to find reliable information on the internet:
● No guarantee that the information is accurate or unbiased
● Materials posted on websites are not needed to be checked by others to ensure they are
factually correct
● Some websites are out-of-date
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10. Communication
How to evaluate the reliability of information found on the internet:
● Some commercial websites are biased
● If a website has excessive advertising, it may be unreliable
● Websites ending with .gov and .ac are often more reliable
● Comparing information with other sources/books
● See if responsible bodies have endorsed the website
● If a website has testimonials, this indicates reliability
● Check the date of the website → may be out-of-date
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11. File Management
11.1 Manage Files Effectively:
File Type
Uses
css
cascading style sheet
Stylesheet that is attached to webpages (normally
html) to define the colours/fonts etc.
csv
comma separated values
Generic file format that takes data in the form of
tables and saves it in a text format that separates
data items by commas. Can be used with
spreadsheets/databases.
gif
graphics interchange format
Stores still/moving images and stores small file
sizes efficiently
htm
hyper text markup language
Text-based language that displays information as a
web page.
jpg
joint photographic expert group
Uses for lossy compression for digital
images/used for complex images
pdf
portable document format
A document that has been converted to an image to
protect the file from being edited. It displays text and
graphics in the same fixed layout and reduces file
size (compressed). It allows for digital signature
png
portable network graphics
Lossless data compression without decreasing the
image quality. Mostly used for internet images.
rtf
rich text format
Saves some of the formatting within the text and
does not allow graphs/comments
txt
text
The file is not formatted and can be opened in any
word processor (generic file format)
zip
zip
Container that can contain almost any file type in a
compressed format. It is used to reduce the no. of
bytes needed to store/save/transfer the file.
Generic File Type - file types that can be opened on any platform/application software - some
formatting will be lost but the info will be the same
● Common generic file types:
○ Comma Separated Values (.csv): Takes data in the form of tables and saves it
in a text format that separates data items by commas.
○ Text (.txt): The file is not formatted and can be opened in any word processor
○ Rich Text Format (.rtf): text file that saves some of the formatting within the
text
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11. File Management
Non Generic File Type - files that are not always possible to be opened on all platforms
● E.g. File types by Microsoft Office - (.xlsx), (.docx), (.accdb)
Why are generic file types needed?
● Allow users to save files so that they can open the files on any platform/software (e.g.
mobile phone to PC)
● Create a standard so other software can understand the contents
Image Files
Audio Files
Website Authoring
Compressed File
GIF
MP3
CSS
RAR
HTML
Zip
JPG
PDF
PNG
MPEG
Compression - reducing file size
● Why?
○ Save storage space
○ Allows quicker transmission of files
■ Smaller file = fewer packets = faster transmission
● Largest files are often image/video files → need to be compressed but also ensure that
the video/image quality is good
Practical: Compressing Images using photoshop:
Option 1: Change image size
Option 2: Decrease image quality
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11. File Management
Practical: Compressing Folders:
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12. Images
12 Images:
●
Need to reduce image resolution to increase transmission speed
Practical: Resizing/Rotating an image w/wo locking aspect ratio
Practical: Reflect//Rotate/Crop an image
Practical: Adjust the color depth of the image using Photoshop
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11. File Management
Practical: Adjust the brightness/contrast of an image in Photoshop
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Practical Notes for Paper 1
Practical Notes for Paper 1 - Theory:
13. Layout:
Explain why headers and footers are needed:
● Make sure each page have elements like: Page numbers, Book/document/chapter,
Logo, Titles, Filename placed consistently
● When put in header/footer, it will appear on every page so it saves time rather than
typing them on every single page.
14. Styles:
Corporate branding/house style:
● A specific style that is adopted for work you produce that ranges from company logos
and recognised colour schemes, fonts, font sizes
Why are consistent styles required?
● Make sure that all the documents and other materials from the organisation have
consistency
● Save time planning, setting up, formatting documents
● Support brand recognition
15. Proofing:
Why are automated suggestions given by spell checkers not always correct?
● The language/dialect used in checking the spelling could be different, e.g.English (US)
● Names/proper nouns might be highlighted as an error
● Similar sounding words need to be checked, i.e. where, were, wear
● The spell checker may not understand the word if it is very badly misspelt
● The word may not exist in the spell checker dictionary
Verification: Way of preventing errors when data is copied from one medium to another
Verification methods
Visual verification
visual comparison of data entered with a data source
Double data entry
entering data twice by 2 different people and the computer
compares the two sets of data
If word used ‘verification’ is used in question, call method ‘visual checking’ If word not used in
question, call it ‘visual verification’.
Need for Validation and verification:
● Reduce errors in data entry
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Practical Notes for Paper 1
17. Document Production:
Widow: A paragraph-ending line that falls
at the beginning of the following page or
column, thus separated from the rest of the
text. (They have a past but no future.)
Orphan: A paragraph-opening line that
appears by itself at the bottom of a page or
column, thus separated from the rest of the
text. (They have no past but a future.)
Why is it necessary to use page, section, column breaks
● Want to apply different formatting in the same page without disrupting the formatting of
the whole page.
● Don't want headers on some sections and want it on other sections
● To enable page orientation to change between 2 pages.
● Avoid widows and orphans
Why are mail merge documents created?
● Produce more professional documents
● Fewer errors in typing details
● Process is faster than typing in each person’s detail individually
● Easier to personalise the document
18. Data Manipulation:
Flat file database - Stores all data in one table only, which is organised by rows and columns
Relational database - Stores data in multiple tables. The tables are linked and there is a
primary key and a foreign key in the linked table.
How to create a relational database from two files?
1. Open database package
2. Select database tools
3. Import the files into separate tables
4. Primary key identified
5. Foreign key identified
6. Click relationships
7. Primary key dragged to foreign key
8. Save the database
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Practical Notes for Paper 1
Primary key - Field that holds unique data. It is a unique identifier.
Foreign key - Regular field in one table which is being used as the primary key field in another
table. Used to provide the link (relationship) between the tables.
Advantages and disadvantages of using relational database rather than flat-file database:
Advantages
●
●
●
●
●
Disadvantages
Duplicated data is reduced
Database space not wasted because
there are no unnecessary duplicated
data
Quicker to enter data as there are no
duplicates
Quicker to update data
Easier to produce reports
●
More complex to set up than a flat-file
database
20. Data Analysis:
Formula
Always start with equal sign and uses mathematical operators
of including functions
Function
Has a predefined name to perform a particular calculation (e.g.
SUM/AVERAGE)
Absolute reference
A reference that is "locked" so that rows and columns won't
change when replicated. Uses dollar symbols like $A$3.
Relative reference
When a formula with relative cell references in copied to
another cell, the reference changes based on a relative
position of rows and columns
Ranges
A collection of cells
Named range
A collection of cells given a name
Nested formulae/functions
Having one formula or function inside another one
Why should a named range be used?
● Used if the range of cells is used many times
● Easier to remember a name than cell references
● Only has to type in the name rather than cell references so reduces typing errors
● If the range of cells replicated, the named range still refer to the same group of cells
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Practical Notes for Paper 1
Excel Formulas:
Mathematical Operators:
Addition
+
Subtraction
-
Multiplication
*
Division
/
Indices
^
Functions:
SUM
=SUM(A1:A4)
AVERAGE
=AVERAGE(A1:A4)
MAX
=MAX(A1:A4)
MIN
=MIN(A1:A4)
INT
=INT(A1)
takes whole number part and ignore digits
after decimal point
ROUND
=ROUND(A1, 0)
ROUND (cell, no. of decimal places)
COUNT
=COUNT(A1:A4)
Counts the number of numeric values
COUNTA
=COUNTA(A1:A4)
Counts the number of numeric or text
values
COUNTIF
=COUNTIF($A$1:$A$4,”Yes”)
COUNTIF (range, criteria)
IF
=IF(A1>5,”Yes”,”No”)
IF(criteria, value true, value false)
SUMIF
=SUMIF($A$1:$A$4, Yes,
F4:F10)
SUMIF(range, criteria, sumrange)
HLOOKUP
=HLOOKUP(B6,
$B$2:$H$3,2,FALSE)
HLOOKUP(lookupvalue, table, row
number, appropriate/exact match)
VLOOKUP
=VLOOKUP(B3,$A$2:$B$8,2,FA
LSE)
VLOOKUP(lookupvalue, table, column
number, appropriate/exact match)
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Practical Notes for Paper 1
21. Website Authoring:
Structure of a webpage:
<head>
● Title of the webpage
● Default target window
● Meta Data
● Styles
● Scripts
● Character set
<body>
● Style instructions
● Table content
● Paragraph
● Hyperlinks
● Headings
● Images
Three web development layers:
1. Content Layer - enter the content and create the structure of a webpage
2. Presentation Layer - display and format elements within a web page. It is defined by
cascading style sheets.
3. Behaviour Layer - enter scripting language to elements within a web page
Function of a hyperlink:
● Move your position within a page
● Open another page
● Send an email
Relative file path: only show the name or file path destination of the file. It does not need a
domain name and can only be used to find files on the current site
Absolute file path: gives the full web address/full path. It always has the domain name and can
be used to find files on a different website.
Cascading style sheets: a text based language that is created and added to web pages to
define the font styles, colour, background etc…
Because stylesheets are linked to all web pages within a website, a relative file path must be
used
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Practical Notes for Paper 1
Style
Class
Limited number of styles
Styles are pre-defined
Styles are defined in the head section
Styles are used once
Class definition name starts with a full stop
Used for adding/changing style within CSS
Subtypes within an element
Classes are user-defined
Classes are styles saved for future use.
Upload and publishing the content of a website using ftp:
● Register for domain name
● Use File Transfer Protocol to upload files to the web hosting space
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