Hi, we had learnt what is a user interface in my previous article, now let us learn what are the different types of user interfaces.
User interfaces may be of three types- command line interface, graphic user interface and menu-driven interface. Each type of user interface with its merits and demerits are explained below:
Command line interface (CLI) - This type of user interfaces allows the user to interact directly with the computer by typing commands. Typing commands is not that easy because you just can’t type anything, you have to type very specific words, so that computer is able to understand.
Advantages of using command line interface are:
- It is faster than the other types of user interfaces.
- It is cheaper to use as a lesser resolution screen can be used.
- Lesser memory (RAM) is used.
- Lesser CPU processing time is needed.
- It doesn’t need Windows to run.
Disadvantages of using command line interface are:
- It can be challenging to use for people who don’t know the specific commands to operate it.
- A lot of commands have to be learned to use this interface.
- One needs to be very specific and careful when typing the commands. Even a single spelling mistake may lead to instruction failure.
Graphic user interface - A graphical user interface (GUI) is the most common type of user interface in use 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.It helps you to select objects.
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 forWhatYouSeeIsWhatYouGet. 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.
Advantages of graphic user interface are:
- This type of user interface is easy to use, especially for a beginner.
- It is easy to explore and find your way around the system using a WIMP/ GUI interface
- You do not have to learn complicated commands.
- There are usually a reasonable 'help' system included with WIMP interfaces
Disadvantages of graphic user interface are:
- GUIs take up a much larger amount of hard disk space than other interfaces.
- They need significantly more memory (RAM) to run than other interface types.
- They use more processing power than other types of interface.
- They can be slow for experienced programmers to use. These people often find CLI interfaces much faster to use.
- You get the benefits of WYSIWYG.
- They let you exchange data between different software applications
Menu-Driven Interface - 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 abc, press 2 for def, press 3 for ghi'?
Most of the software that you use has 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 interface are:
- It is 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 your 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.
- It is fairly easy for the software programmer to create the same menus in different languages.
Disadvantages of menu-driven interface are:
- 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, colors might clash and be difficult to read, font style might be hard to read.
