GCSE ICTUser 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 interfacesA 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:

• 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.

Command – driven User Interfaces

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 interfacesThis 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.

F1 Load new programF2 Run programF3 List files on discF4 Backup options

ESC Quit

Main Menu Backup Options

F2 Make backup copyF3 Main Menu

F1 Restore a file

F2 Pressed

Make Backup CopyEnter name of file

fred.txt

Select driveA C

OK

F4 Pressed

CANCEL

In this example a menu-driven user interface has been used to copy a file called fred.txt to a user’s floppy disk.

iPod Menu System

Graphical user interfacesA 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 word-processors, 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 OSWindows 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 DesignIt 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.