AS Level
ICT
Revision
Guide
CONTENTS
CONTENTS ............................................................................................................................... 2
BASIC EXAMINATION TECHNIQUE ........................................................................................ 3
UNIT 1 ....................................................................................................................................... 4
Unit 1_1 Data Information and Knowledge ................................................................................................................ 4
Unit 1_2 The Value and Importance of Information ................................................................................................... 5
Unit 1_3 Quality of Information .................................................................................................................................. 6
Unit 1_4 Validation and Verification ........................................................................................................................... 7
Unit 1_5 Capabilities and Limitations of ICT .............................................................................................................. 8
Unit 1_6
1_6_1
1_6_2
1_6_3
1_6_4
Uses of ICT ................................................................................................................................... 9
Business .............................................................................................................................................. 9
Education........................................................................................................................................... 10
Healthcare ......................................................................................................................................... 10
The Home .......................................................................................................................................... 13
Unit 1_7
Presenting Information ................................................................................................................ 15
Unit 1_8
Networks ..................................................................................................................................... 17
Unit 1_9
Human Computer Interface ........................................................................................................ 20
Unit 1_10
Social Issues ............................................................................................................................... 22
Unit 1_11
Databases .................................................................................................................................. 24
2
Basic Examination Technique
Anything in the specification can be used as a question. Get a copy of the specification and
use it as a revision checklist. Specification can be obtained from www.aqa.org.uk
Answer all the questions on the paper in the right order. Fill in the question numbers on the
front page of the exam paper.
Use correct English and not "text message language."
readable. Don't use correction fluid.
Make sure your handwriting is
The best way to calm yourself down at the start of the exam is to read each question twice.
Every word in the question is there for a reason.
If the question asks you about a certain scenario, make sure that your answer is relevant to
this scenario.
All answers require more than a single word or phrase.
Use correct technical terms. Do not use trade names e.g. talk about a "Database
Management System" not "Access". Talk about a "Spreadsheet Package" and not "Excel".
Look at the mark allocation for each question.
When asked for an example, use ICT examples.
It might be a good idea to start every answer on a different piece of paper.
Think about what the examiners are asking you to do:
Name
List
Define
Outline
Describe
Explain
Suggest
State
Give the name of something
Give several names
What is meant by
A brief summary of the main points
Give a description (requires several
sentences)
You have to show your understanding
of something
There are several possible correct
answers and you have to make a
suggestion and explain why your
answer is a good one
List but give reasons
3
Unit 1
Unit 1_1 Data Information and Knowledge
Data are strings of raw facts and figures that have no meaning
e.g. manu3nor5qpr2arn3
Information is processed data that has been given meaning
e.g.
Manchester United
Queens Park Rangers
3
2
v
v
2 Norwich City
3 Arsenal
Knowledge is information that has had rules applied to it and is used to aid decision making
e.g.
Manchester United’s and Arsenal’s wins mean that they will now face each other in the
FA cup semi-final
Data, Information and Knowledge have specific meaning in this subject and it is a common
mistake to use them interchangeably!
e.g.
Explain, with examples, two ways that make information valuable to an organisation. [4]
“Organisations need data to make sure that they make the correct decisions.
An example of this is data that is on time.”
This candidate has answered the question using the term Data and therefore gains now
marks!
Coding / Encoding
Shortening data so that it is represented by a code e.g.
LCD32LG54ER (an 32 inch LCD TV, made by LG) – it is NOT deliberately hiding or
disguising data (that’s encryption)
Why Encode
Quicker data entry
Less storage space
Less likely to make data entry errors
Easier to validate
Disadvantages
Loses meaning
Loses precision
Can lead to value judgements
4
Unit 1_2 The Value and Importance of Information
Managers need Information because:
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Decision making
Strategic planning
Day to day managing (monitoring progress)
Directing
Controlling
Forecasting
Competitive advantage
Targeting resources
What makes Information Expensive?
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Employing someone to create data collection forms
Setting up questionnaires
On-line forms
Travelling costs
Collation costs
Costs to collect from other systems
Buying in the data (information)
Data Entry
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Human resources
Time costs
Hardware costs
Processing
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Keeping systems up-to-date
Backups
Maintenance
Technical staff
Hardware
Software
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Unit 1_3 Quality of Information
What makes Information Valuable?
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Up-to-date
Relevant
Accurate
Complete
Timely
Correct format
How to find Information
Internal sources
Observation
Result of an action
Questionnaire
Work Study
Interview
External
Online Sources
CD-ROMs
Non-ICT Sources
Bought-in
Media
Government Statistics
Demographics
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Unit 1_4 Validation and Verification
VERIFICATION means checking to see if something is correct e.g. that the customers title is
“Mr”
VALIDATION means checking to see if it is reasonable e.g. that Sam did really get 106 out of
100 in a Maths test.
When you fill in a form on a web site they want your real e-mail address. There is usually a
validation check on the e-mail address, which means that anyone@anything.com will usually
be accepted. However, some clever companies then send an e-mail to the address given to
VERIFY its accuracy. The double entry method is a common form of verification e.g. typing in
a password twice. The last form is to proof read data.
You need to be able to name and describe different validation checks (i.e. you must know what
each one does):
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Presence check
Range check
Format check
Uniqueness check
Look-up list
Length check
Type check
Check digit check
What are the problems with inaccurate data?
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Can lead to incorrect decisions being made
Loss of trust
Unprofessional image
Loss of goodwill
Prosecution
How do errors occur?
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Processing errors
Transmission errors
Transcription errors
Transposition errors
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Unit 1_5 Capabilities and Limitations of ICT
Benefits
 Increased speed of processing
 Vast storage capacity
 Ability to search data in different ways
 Instant response
 Accurate and consistent results
 Communication
 Improved company image
 Work 24/7
 Ability to search and combine
 Improved security (Backups)
Disadvantages
 Job losses
 Faults in software
 GIGO
 Information overload
 Computer crime
 Lack of hard and software standards
 The Nature of Software
 Changes in circumstances during development
 Organisations constantly changing
 Speed of Implementation
 Compatibility
 Insufficient testing
 Poor communication with user
 Abilities of user
 Poor-post implementation procedures
 Maintenance Procedures
 Cost
 Hardware
 Support
Why do IT projects fail?
 Latest technology
 Focused on cost alone
 Human resources ignored
 Users aren’t involved in design phase
 Users given unrealistic outcomes
 Managers not IT literate
 Focus on technology not people
 Lack of consultation
 Underestimation of cost
 Underestimate of time
 Over ambitious
8
Unit 1_6
Uses of ICT
1_6_1
Business
 Telephone and Internet banking
 Allows 24/7 access
 Transfer funds, pay bills, access statements
 ATMs
 Allow people to access cash 24/7 with a PIN (Personal Identification Number). Now
you can access funds even abroad!
 Debit cards (switch)
 Using the Chip and PIN you can pay for things without having to have access to cash.
 Cheques
 Using MICR
 Direct Debit
 Allow people to be paid automatically, or even pay theory bills without thinking about it!
Downsides
 Identity theft
 No need for identity to have goods
 Fraud
 Theft of PIN and Magnetic strip (via ATMS and at retail outlets, Petrol Stations)
 (TK Max)
E-Commerce – Benefits to Organisation
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No need for high street presence saving costs
From personnel and shop.
Much wider audience
Just in time delivery
Storage of customers’ details is a valuable marketing tool.
No need for high street presence saving costs
From personnel and shop.
Much wider audience
Just in time delivery
Storage of customers’ details is a valuable marketing tool.
E-Commerce – Benefits to Consumer
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Allows 24/7 access
Shop from anywhere I world from home
No need to leave home
Can have good delivered (to a friend)
Specialist items easier to source
Goods are often cheaper
Comparison is easy
Downsides
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Fraud
You can’t feel or see the goods
May have to wait for delivery
Substitutes can be made
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Manufacture
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Project management software
Expert systems
CAD/CAM (more in a minute)
Robots
Order entry and processing systems
Computer Aided Design
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Can produce 3-D models
Cheap to make adjustments
Used for calculations
Can be used for walk-through
Models can be viewed fro any angle
Drawings can be enlarged indefinitely (vector graphics)
Computer Aided Manufacture
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1_6_2
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1_6_3
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Much quicker than humans
Much more accurate that humans
Can work 24/7
Reproduces the same thing every time
Can be used in hostile environments
Don’t need to be paid
Education
Increased use of DB/SS/WP/DTP
Interactive teaching aids
The internet
Distance learning
Interactive boards
Special facilities for students with disabilities.
MIS
Electronic registration
Cashless catering
Mini Laptops
E-Learning
CAL (Computer Assisted Learning)
CBT (Computer based Training)
Authoring Software
Healthcare
Medical records stored on databases
Donor databases
Computer controlled devices (pacemakers, organs)
Monitoring devices
Expert systems
Remote operations
Key hole surgery
10
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Computer modelling for drugs
Booking online
Electronic Patient record keeping (EPR)
 Many staff may need access to a patients records at the same time
 Huge number of paper based records are now stored electronically
 Clarity – handwritten notes can be difficult to read
 Loss of records is reduced
 Misplaced records is reduced
 Mobile access to records (PDAs etc)
 Data consistency
 Backups
 No need to transport paper based files
Blood tracking
 Used when a patient donates blood
 Taken from donor, grouped into blood type
 Stored at the National Blood Transfusion Service – given a coded label
 Matched blood sent to hospital
 ID badge scanned and used when needed
 Patients wristband is scanned and matched with bloods ID
Sensors
There are two major types of sensors, analogue and digital. Analogue are able to measure
gradiations between two figures and digital are only able to measure specific values
(DON’T say whole numbers!)
Data measures by sensors
Temperature
Blood pressure
Central venous pressure
Pulse
Blood gases
Blood sugar
Brain activity
Electrical activity (electrocardiogram)
Respiratory rate
Advantages of sensors
Measurements never missed
Real-time monitoring
Medical staff are freed up
Reduction of costs
Trends can be spotted
More accurate readings
Scanning devices
Magnetic resonance image (MRI)
Uses the natural electromagnetic nature of bodies to produce scans of the insides opf patients,
without doing harm, unlike x-rays. Used for heart and blood vessels, examining joints,
checking organ function
11
Computerised axial tomography (CAT)
Uses x-rays at differing angles in order to produce a much more detailed image than an
ordinary x-ray.
Advantages of scanners
High cure rate
You don’t have to cut someone up
Helps the planning of operations
Faster diagnosis
Scans can be done routinely
MRI scans are safe (scary, but safe)
Disadvantages
It’s expensive
They can break down
CAT scans use x-rays and are therefore dangerous
The patient needs to be very still for MRI scans
Backups MUST be taken for critical systems such as the data taken from sensors – backups
can be onsite (RAID drives, backup servers) or offsite complete mirror systems.
UPS – an uninterrupted power supply. These can be used to make sure that computer
equipment continues even if there are power fluctuations or even power failure.
Expert Systems
An expert system is an ICT system that uses artificial intelligence to make decisions based
on data supplied in the form of questions. Meaning that the system models the
processes of consulting an expert in the field.
Expert systems contain the following elements
Knowledge base – a set of knowledge about a particular subject
Inference engine – a set of rules on which to base decisions (usually an if-then
structure)
User Interface – users ask questions and are provided with answers by the system
You can create an expert system from scratch or you can use a piece of software that will help
you to build one. This is called an EXPERT SYSTEM SHELL. The expert system shell
consists on the Inference engine and the user interface, but NOT the knowledge base. The
knowledge base needs to be supplied by the user. Some examples of software languages are
PROLOG and ASPRIN.
Some medical expert systems are MYCIN and NEOMYCIN.
Advantages
 Consistency – you always get the same answer to the same question
 Cheaper – than employing experts
 Large pool of knowledge
 Uses ALL the information that it has
Disadvantages
 No common sense
12
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Can make really daft errors – remember GIGO for example
Not able to be intuitive
Unable to tell you when it doesn’t know
The rules and knowledge MUST be correct
Artificial Intelligence
Intelligence is very difficult to define, but a definition of artificial intelligence isA reasoning process performed by computers which allows computers to draw
deductions, produce new information and modify or write new rules.
Neural networks are biological computer systems you brain!
Advantages
Good at circumstances when rules are difficult to apply or not understood
When there are plenty of examples to learn from
Structure can be identified from existing data
Disadvantages
They are only suited to certain tasks
Examples used to teach the system need to be chosen carefully, otherwise anomonlies
can arise
Neural networks can learn from their own ”experience”
Parallel processing is what we do – we are able to process many parts of data at the same
time. Most computers are unable to achieve this. They process data so fast, one bit at
a time, that for most circumstances it makes no odds. However, when a vast amount of
data is being processed, i.e. in a super computer predicting weather or a computer
buying and selling shares, then they can use parallel processing and process bits of
data simultaneously.
Ordinary ICT systems are good at:
Fast processing
Obeying a set of rules
They are not good at
Adapting to circumstances
Dealing with data in parallel – the like to deal with each circumstance one after the other
Dealing with data that may be incorrect
1_6_4
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The Home
Games
Photography
Music
MIDI
Interactive TV
Home Shopping
On-line Booking
Email
Dating
Gambling
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Mobile Phones
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Unit 1_7
Presenting Information
You should make sure that you are familiar with the common features of each type of
software.
Format
Text
Tabular
Graphics
Audio
Animations
Video
How to choose the format
Needs of user
Target audience
Complexity of the information
How to present the information (face to face, online, downloadable)
Word Processing
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Templates
Mail Merge
Indexing
Macros
Thesaurus
Spellchecker
Grammar checker
Desktop Publishing
The difference – a good rule of thumb is that a document that includes images is DTP. DTP is
used for high quality, one off documents.
Advantages
 More control over appearance
 Easier to integrate files from other packages, such as images, charts etc
 Text and graphic frames mean easier positioning
 Files that are compatible with publishing can be produced
CSS (Cascading Style Sheet) – style and formats are contained in a separate file and
therefore if a change is made it becomes a global change in the document (or
webpage)
Presentation Software
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More professional
Summaries Information
Printed versions available
Multimedia
Stored and can be edited
15
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Presented using different hardware (TV, computer, projector)
Databases (see below Unit 1_11)
Web Authoring Software
The name for software that allows users to create websites.
Key features
Text and images
Formatting
Tables, to organise the look of webpages
Hyperlinks
Anchors (a kind of internal hyperlink that goes to a point in the page)
Mailto links
Preview the website
Multimedia and animation such as Flash
Keywords
 Hyperlinks
 Formatting
 Templates
 Frames
 HTML
 CSS
 Forms (to collect data)
Cascading Style Sheets
This allows the look of a website to be controlled at one single point. Each part of the website
(the size, format, font, colour etc) is stored in one file and then when a change is made
to this file it runs throughout the whole website.
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Unit 1_8
Networks
You should be able to explain the difference between a LAN and a WAN and to give an
example of each.
The advantages of LAN networks are:
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File and printer sharing
Communication over a network
Ease of administration
The disadvantages are:
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In a server-based network, users are reliant on a server
Security problems
Cost of hardware (e.g. cabling, servers, network interface cards)
You should understand the difference between parallel and serial transmission (serial transfers
one bit at a time).
You need to understand the difference between a "server based network" and a "Peer-to-peer"
network. You need to understand the advantages and disadvantages of each.
You need to understand the different types of "Network Topology". You should understand the
differences between a RING, BUS and STAR network. You should be able to draw a diagram
of each.
Key Equipment
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Network interface card
Hub (or switch which can examine packets of data) allows several computers to
communicate with each other
Routers acts as a gateway (commonly known as broadband MODEM, but thers is NO
SUCH THING!)
Network Software
Cables (fibre optic – expensive, fast, long distance, Copper – cheaper, slower only
about 100m, comes in two flavours, unshielded and shielded (coaxial))
Wireless access points
Networks vs Standalone
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Standalone is cheaper
Less expertise needed for standalone
Less potential for viruses when standalone
Not as hardware dependant when standalone
Advantages of Networks
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File sharing
Hardware sharing
Software sharing
Lower software costs
17
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Improved security
Easier to implement usage policies
Easier backups
Improved communication
Central maintenance and support
Disadvantages
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Technical knowledge needed
When the server fails everything fails
Initial setup costs
LAN – a network on one site
WAN – a network across two or more sites
The Internet
A network of networks.
Benefits
Cheap communication
Multimedia streaming
Transfer files
Research
Sharing resources
Shopping
Video conferencing
Disadvantages
Inappropriate material
Exploitation – particularly of children
Cyber bullying
Spam
Loss of privacy
Incorrect or inaccurate information
Communications
Instant messaging
Webcam
VOIP (voice over Internet protocol)
Chat rooms
SMS
E-mail
E-Mail
Advantages
Virtually instantaneous
Quick direct communication e.g. LOL
Attachments
Cheaper than snail mail
Available from different devices
Environmental issues
Disadvantages
18
Not everyone has email
Not as formal as snail mail
Junk mail and spam
Security
File Transfer Protocol (FTP)
This sets the protocol, the rules, for transferring files across the Internet.
Extranet and Intranet
Extranets are opened to a select group of users outside the organisation such as customers or
suppliers.
Intranets are a private network of information available only to specific groups, such as
employees.
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Unit 1_9
Human Computer Interface
HCI stands for both "Human-Computer Interface" and "Human-Computer Interaction". The
two should not be confused. Human-Computer Interaction refers to more than just the
interface.
When thinking about interfaces, consider things like ATM machines, cashpoints and planes as
well as computers.
Interface styles are:
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GUI (Graphical User Interface)
Command Line Interface
Natural Language Interface
Menu driven
Form driven
GUIs are increasingly popular because they have a range of features to facilitate speed of
learning and ease of use including:
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Windows (to facilitate multi-tasking)
Menus (pop-up and pull-down)
Icons and buttons
Pointers (although keyboard shortcuts are still needed for more experienced users)
When designing a data entry form, interface design considerations could be:
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Forms should have a title
Forms should not be too cluttered
Obvious buttons for navigating records, Exit, Cancel, Help
Length of data entry boxes
Drop-down combo boxes
Radio buttons/checkboxes
Online Help/Context Sensitive Help
Things to consider when designing an interface
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Input methods
Use of colour
Consistency
Use of pictures/icons
Use of text
Sound
Consistency
Input Devices
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MICR
OCR
OMR
Keyboard
Joystick
Games devices
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Biometric devices
Microphones
Touch sensitive screens
Output Devices
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Printers
VDUs
Speakers
If applications have a "common user interface", it can increase speed of learning and,
therefore, reduces training costs. The ability to import/export data between integrated
applications is not an advantage of the interface!
Don't confuse the operating system with the user interface!
Don't confuse voice dictation systems with natural language interfaces (Interacting with
a computer system using a natural spoken or written language)!
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Unit 1_10 Social Issues
Computer Misuse Act
The three levels of offence are:
Level One: Unauthorised access (e.g. someone who breaks into a system to be nosey or just
for the hell of it).
Level Two: Unauthorised access with a further intent (e.g. someone who breaks into a
network to steal money).
Level Three: Unauthorised access to modify data (e.g. someone who breaks into a network
to plant a virus, which corrupts data).
The computer misuse act is not used as much as it should be because many businesses (e.g.
financial institutions) do not want to acknowledge that their systems are vulnerable. If it
became public knowledge that their systems had been hacked, the bad publicity could affect
their share price.
Copyright, Designs and Patents Act
When you buy a piece of software, you do not own the software itself. What you own is a
licence to use this software on one computer at a time (a single user licence).
If an organisation wants to install the software on a network, it could buy a network licence or a
site licence.
It is illegal to duplicate, download or transmit copyrighted software.
Software companies can guard against software piracy by the use of registration numbers,
dongles, or by trying to make disks or CDs "impossible" to duplicate.
Organisations should have policies to ensure that they are always fully licensed.
Health and Safety
There are several laws governing health and safety at work. Organisations can be sued by
their employees if they are guilty of not following guidelines. Consider the example of the
HSBC bank. Remember to refer to IT health and safety problems only!
Health and Safety problems can include:
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Eye-strain (breaks, brightness controls, lighting)
RSI (breaks, ergonomic keyboards, adjustable chairs, software design)
Stress (software design, training)
Neck-Strain (tilting monitors, adjustable seating)
Data Protection Act
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Why was the data protection Act introduced? (Because of privacy concerns about large
amounts of personal data being held. Because computers can store vast quantities of data
and process it very quickly. Consider the case of James Wiggins)
What sort of data does it cover? (personal data on living and identifiable individuals that will
be automatically processed)
What is the data register? Anyone wishing to hold personal data must say what data will be
held, who the data will be passed on to, how long the data will be held for, the purpose for
which the data is held, the sources from which it will be obtained).
What is the role of the Information Commissioner? (to maintain the register, to spread
information about the DPA, to encourage organisations to introduce codes of practice, to
consider complaints and to prosecute offenders).
What are the 8 principles of data protection?
Data must be . . .
1. Obtained and processed fairly and lawfully
2. Held for a lawful purpose as described in the register
3. Adequate, relevant and not excessive in relation to registered purpose
4. Accurate and up-to-date
5. Held no longer than necessary for the registered purpose
6. Used only for the registered purpose
7. Accessible to the individual concerned
8. Surrounded by proper security
What are the rights of data subjects? (the right to see information, the right to have errors
corrected, the right to complain, the right to compensation)
What are the Exemptions from the Act? (payrolls, pensions, national security, recreational,
electoral roll, tax, credit reference agencies).
Acceptable Use Policies
Every organisation should have an acceptable use policy and make sure that staff do know
what is and is not acceptable. This should cover:
 Acceptable use of hardware
 Acceptable use of software
 Appropriate use of the Internet
 Security
 Training
Malpractice – is when a user does something that contravenes the acceptable use policy of an
organisation.
Crime – is when someone breaks the law.
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Unit 1_11
Databases
What is a database?
A database is a large collection of data items and the links between them. The software
that is used to access the data is called the Database Management System (DBMS).
Keywords, queries, forms, fields, key field, record, relationships, sorting, reports.
Advantages of Databases:
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Vast storage capacity
The ability to search, sort and combine data
The ability to share information
The ability to set passwords/access levels
Terminology Associated with databases
Data Inconsistency – the same data appears differently throughout the system
Data Redundancy – the same data appears over and over again
Data Dependence – Any change in the data format or structure means that it must be
changed throughout the system.
Data Lacks Integrity – It’s just plain wrong!
Flat File v Relational Databases
Advantages
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Data Redundancy (the same data entered over and over again takes up unnecessary
space and can slow down the performance of the database)
Data Inconsistency (if the same thing is entered repeatedly, mistakes will inevitably be
made
Time spent entering data (faster if the same data does not have to be entered
repeatedly)
Ease of updating (e.g. what happens if someone changes her name?)
Much easier to search for information in a relational database
Much easier to combine data in a relational database
Data Integrity – Data is only kept in one place, so when it’s updated it updates
throughout the database
Can build an application around a relational database.
Relational databases are very adaptable
Disadvantages
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Hard to set up a relational database
More expensive
Inappropriate for simple lists
Things to remember when talking about databases:
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Data types (numerical, alphanumeric, alpha, Boolean)
Query
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Sort
Validation
Verification
Data Capture
Input – Process – Output
Data – Information – Knowledge
Key Field
Links
http://www.theteacher99.btinternet.co.uk/theteacher/ict/ictwjec1.htm
Database Security
Every organisation needs to adhere to the DPA and take reasonable precautions to protect
their data. Some of the ways in which this can be achieved are:
Physical protection
 Lock the computer in a room
 Provide security guards
 Have o a limited number of stations able to access the data
Software protection
 Access rights (read only, read/write, full control, execute)
 Password protection
 Encryption
Distributed Database
A distributed database is one in which the data is spread of several servers in one or more
networks. They are good for data protection, because they are on different servers not all of
the data should be damages if there is an emergency such as a fire and the data is more
difficult to access by hackers. Because there are several servers the speed of processing is
improved.
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