Computer User Interfaces

User interface is one of the most important parts of any electronic device. When the user interact with a computer system the first thing the user notice that how easily the user can interact with computer not how good or quickly the computer system does it.
The Human, the user, is, after all, the one whom computer system are designed to assist. The requirements of the user should therefore be our first priority (Alan et al, 2004 : 12).
Wilbert (2007: 4) defines the user interface

“ The user interface is the part of a computer and its software that people can see, hear, touch, talk to, or otherwise understand or direct. The user interface has essentially two components: input and output. Input is how a person communicates his or her needs or desires to the computer. Some common input components are the keyboard, mouse, trackball, one’s finger (for touch-sensitive screens or pads), and one’s voice (for spoken instructions). Output is how the computer conveys the results of its computations and requirements to the user. ”

There are many types of User-interface use now days. Each computer system has different types of User interface because of different users with different requirements. There are mainly five types of user interfaces or interaction styles according to Wilbert (2007: 3-4 )
1. Command Line
2. Menu Selection
3. Form Fill-in
4. Direct Manipulation
5. Anthropomorphic
Wilbert (2007: 3-4) describes these different interactions styles as follows
Command Line
“ The command-line interface is the oldest and original user interaction style. It requires the user to press a function key or type a command into a designated entry area on a screen.” Menu Selection
“ A menu is a set of options or choices from which a user must choose. On screens, the user selects a choice with a pointing device or keystroke. ”

Form Fill-in
“ The form fill-in style is very useful for collecting information. Today’s typical form structured screen contains a series of controls or fields into which the user either types information or selects an option, or options, from a listing of choices. ”

Direct Manipulation
“ A direct manipulation interface, as found in graphical systems, enables the user to directly interact with elements presented on the screen. These elements (called objects) replace the keyed entry of commands and menus. ”

Anthropomorphic
“ An anthropomorphic interface tries to interact with people the same way people interact with each other. Anthropomorphic interfaces include spoken natural language dialogues, hand gestures, facial expressions, and eye movements. ”

Combining different type’s user interactions styles, computer system designer made a new interface called Graphical User Interface (GUI) TYLE ADVANTAGES DISADVANTAGES
Wilbert (2007: 3) describes the Introduction of Graphical User Interface (GUI) into modern computer system

“ Greatly improved technology in the late twentieth century eliminated a host of barriers to good interface design and unleashed a variety of new display and interaction techniques wrapped into a package called the graphical user interface or, as it is commonly called, GUI (pronounced “gooey”) ”
Graphical User Interface (GUI) is most commonly used user interface now days because it meets all requirements that a good user interface should have using interacting technique called WIMP ( Windows, Icons, Menu and Pointing Device ). When the hardware got better, and computers were able to support graphics, GUI was the interface that got popular. GUI was easier to understand and learn because the WIMP ( Windows, Icons, Menu and Pointing Device ) interacting technique made it very user friendly. It also made complexity of the OS from the user which made computers more attractive and more people started to use computers because the user didn 't have to learn complex and long commands.
Niall murphy (2001) discusses the usability for Graphical User Interfaces at: http://reader.eblib.com/
“ With a non-graphical display, one layout of buttons and displays has to be designed and evaluated. With a graphical user interface (GUI) there is no limit to the number of possible layouts. Making each one user friendly, while remaining consistent with the others, is a big challenge. If you do it well, the pay off is an interface that may look simple to the novice, but contains enough sophistication to satisfy the expert user. The interface should always display just the required information, keeping any superfluous information hidden unless specifically requested. ”

GUI was not always the best option because in some computer system the hardware is not that powerful which can cope with the graphical requirement of the GUI and also some low-level functions of the OS were not easy to access. So this is why now most Operating System (OS) developer that used GUI still kept Command line interface (CLI) as part of the OS to facilitate advanced level access to computer system. As GUI is improving the need for better hardware is also increasing which is kind of a problem for OS developer but still GUI is much better than any other interface because as our first priority is always users so keeping that in mind GUI is the best option for any computer system which interacts directly with the user.

References
Alan Dix, Janet Finalay, George D.Abowd, Russel Beale. (2004) 3rd ed. Essex: Prentice Hall.

Galitz, Wilbert O. (2007) The Essential Guide to User Interface Design : An Introduction to GUI Design Principles and Techniques [Online]. Available at: http://reader.eblib.com/ Accessed [17th Oct 20011].

Niall murphy (2/26/2001 5:23 PM EST) Usability for Graphical User Interfaces. Available at: http://www.eetimes.com/design/embedded/4023286/Usability-for-Graphical-User-Interfaces. [Accessed 17th Oct 2011]

Wimp (Windows, Icons, Menus, and Pointing Devices) Available at:http://www.bookrags.com/research/wimp-windows-icons-menus-and-pointi-wcs/. [Accessed 17th Oct 2011]

References: Alan Dix, Janet Finalay, George D.Abowd, Russel Beale. (2004) 3rd ed. Essex: Prentice Hall. Galitz, Wilbert O. (2007) The Essential Guide to User Interface Design : An Introduction to GUI Design Principles and Techniques [Online]. Available at: http://reader.eblib.com/ Accessed [17th Oct 20011]. Niall murphy (2/26/2001 5:23 PM EST) Usability for Graphical User Interfaces. Available at: http://www.eetimes.com/design/embedded/4023286/Usability-for-Graphical-User-Interfaces. [Accessed 17th Oct 2011] Wimp (Windows, Icons, Menus, and Pointing Devices) Available at:http://www.bookrags.com/research/wimp-windows-icons-menus-and-pointi-wcs/. [Accessed 17th Oct 2011]