GCSE ICT
User Interfaces
Learning Intentions:
• To understand the concept of a
Windows operating system and have a
basic understanding of GUI.
Success Criteria:
• To be able to identify the three types
of operating systems and their
advantages and disadvantages.
Interacting with machines
• People need a way of interacting with machines if
they are to be useful.
• Think of a vending machine - you want a drink, but
how do you get the machine to give it to you?
• Well, you will have to read the display and follow the
instructions, put your money in the slot, press the
right buttons and eventually your drink will pop out
(hopefully!).
• You got the machine to give you a drink by
interacting with it via its 'user interface'.
• Think about all of the other machines that you
interact with on a daily basis. You have to do certain
things and make choices to get them to work.
• We will be looking at different types of user
interface in this lesson.
User Interfaces
The human computer interface is what allows the
user to communicate with the computer and is
often called simply the user interface.
The three main types of user interface are;
•Command-driven
•Menu-driven
•Graphical or GUI.
Command-driven user interfaces
A Command Line Interface allows the user to interact
directly with the computer system by typing in commands
(instructions) into a screen which looks similar to the one
below:
Command – driven User Interfaces
•
You cannot just type in any kind of instruction of course, because the
computer will only react to a definite set of words.
•
These command are very specific, for example in DOS you could type in:
copy c:\item.txt d:\
That tells the machine to copy the file 'item.txt' that resides in the
root directory of drive C: into the root directory of drive D:\
•
•
•
Before Windows was developed, this type of user interface was what
most people used to get the computer to follow instructions. Nowadays,
very few people have the knowledge to be able to use a command line
interface.
An example of this type of interface is DOS (Disk Operating System).
DOS, which stands for Disk Operating System, is a very commonly used
command-driven user interface.
Advantages of Command-driven
User Interfaces
• If the user knows the correct commands then this type of
interface can be much faster than any other type of interface.
• This type of interface needs much less memory (RAM) in order
to use it than other user interfaces.
• This type of interface does not use as much CPU processing time
as the others do.
• A low resolution, cheaper monitor can be used with this type of
user interface.
• A CLI does not require Windows to run.
Disadvantages of Command-driven
User Interfaces
•
•
•
•
•
For someone who has never used a command line interface it can be
very confusing.
Commands have to be typed in precisely, if there is a spelling error the
command will fail.
If you mis-type an instruction, it is often necessary to start all over
again.
There are a large number of commands which need to be learned - in
the case of Unix, it can be hundreds.
You can't just guess what the instruction might be and you can't just
'have a go‘.
The main disadvantage of command-driven interfaces
is that they are very difficult to use if the user is a
beginner or doesn’t know the correct commands.
Command-driven systems can be very unfriendly and
confusing for non-computer experts to use.
CyberSoft(R) PC-DOS Version 5
(c) Cyber Corp 1987-1996
C:\DOS\> copy c:\fred.txt a:\
1 file(s) copied
C:\DOS\>
The correct commands to
copy the file are typed in by
the user at the keyboard
The operating system
displays a message to
confirm that the command
has been carried out
successfully.
Menu-driven user interfaces
This type of interface lets you interact with a computer or device by
working your way through a series of screens or menus.
Think about your iPod or mobile phone, they both use a menu driven
interface. You are presented with a menu, you make a choice and then
the next menu appears on the screen. You make another choice and so
on.
Cashpoint machines (ATMs) are another good example of a menu
driven interface.
Menu driven interfaces can also be verbal rather than visual. Have you
ever made a telephone call and been asked to 'press 1 for operator,
press 2 for accounts, press 3 to report a fault' ?
Most of the software that you use have menu interfaces. You can use
many features of the software by working your way through the menu
options. Have a look at the menus in your word processor or
spreadsheet package and see how many different choices you are
given.
A well designed menu interface is simple to use, you just follow the
instructions and make your choices.
Advantages of Menu – driven
user interfaces
•
•
•
•
•
•
They are extremely easy to use, someone who has never seen the
interface before can work out what to do.
There are no commands to learn or remember.
Step-by-step options are given so that the user doesn't have to
remember anything.
Even if you don't know what to do, you can usually guess you way around
the options
Menu interfaces don't have to be visual, they can be spoken - good for
telephones or for visually impaired people.
They don't need huge amounts of processing power or memory.
Disadvantages of Menu –
driven user interfaces
•
•
•
•
•
A poorly designed menu interface may be slow to use.
It can be irritating if there are too many menu screens to work through
- users get annoyed or bored if it takes too long.
You often can't go to the exact place you want right at the start. You
have to work your way through the menu screens even if you know
where you want to get to.
The menu can take up a large part of the screen so you have to keep
flicking back and forwards between applications.
If the menu is poorly designed it might be hard to read e.g. writing is
too small for people with poor sight, colours might clash and be difficult
to read, font style might be hard to read.
Main Menu
F1
F2
F3
F4
Load new program
Run program
List files on disc
Backup options
Backup Options
F4 Pressed
F1 Restore a file
F2 Make backup copy
F3 Main Menu
ESC Quit
F2 Pressed
In this example a menudriven user interface has
been used to copy a file
called fred.txt to a
user’s floppy disk.
Make Backup Copy
Enter name of file
fred.txt
Select drive
A
C
OK
CANCEL
iPod Menu System
Graphical user interfaces
A graphical user interface is the most common type of user interface
seen today. it is a very 'friendly' way for people to interact with the
computer because it makes use of pictures, graphics and icons - hence why
it is called 'graphical'.
A GUI (pronounced gooey) is also known as a WIMP interface because it
makes use of:
• Windows - a rectangular area on the screen where the commonly used
applications run.
• Icons - a picture or symbol which is used to represent a software
application or hardware device .
• Menus - a list of options from which the user can choose what they
require.
• Pointers - a symbol such as an arrow which moves around the screen as
you move your mouse. Helps you to select objects.
Graphical User Interface
•
All modern operating systems have at least one type of GUI. For
example Microsoft Windows is a GUI, Apple Macintosh has another.
Linux has a number of Graphical User Interfaces available.
•
Many programs that run in Windows are known as WYSIWYG - this
stands for What You See Is What You Get. In the early days of wordprocessors, you typed your essay or letter on the screen, but it could
look completely different on the printer. A GUI normally tries to
ensure that whatever you create on the screen will be very similar to
what appears on the printer or world-wide-web.
Windows OS
• Available on most computers.
• Microsoft first introduced an operating
environment named Windows in
November 1985.
• Developed in response to the growing
interest in graphical user interfaces
(GUIs).
• Microsoft Windows eventually came to
dominate the world's personal computer
market.
Windows OS
Windows OS is simply a
piece of software created
to allow users and the
computer (all it’s
hardware and software)
to communicate with each
other.
To do this in a user friendly way, it uses a
Graphical User Interface…or GUI.
The UNIX GUI
The Mac GUI
The First Windows GUI!
The Later Windows GUI
A few lesser known ones:
A few lesser known ones:
Advantages of Graphical User
Interfaces
• This type of user interface is extremely easy to use, especially
for a beginner.
• It is easy to explore and find your way around the system using
a GUI.
• You do not have to learn complicated commands.
• There are usually good help facilities provided with GUIs.
• You get the benefit of WYSIWYG.
• They let you exchange data between different software
applications.
Disadvantages of Graphical User
Interfaces
• GUI take up a much larger amount of hard disk space than other
interfaces.
• GUI need significantly more memory (RAM) to run than other
interface types.
• GUI use more processing power than other types of interface.
• GUI can be slow for experienced programmers to use, they find CLI
interfaces much faster to use.
User Interface Design
It is the job of a user interface to make a program easy to
use.
A good user interface should:
- Be attractive and pleasing to the eye.
- Be easy to use.
- Ensure all screens are consistent.
- Have all options clearly shown.
- Have clear warning messages when someone makes a mistake.
- Have online help and support.