Human Computer Interface design

Manohita Gurram

Nov 19 2002

Good interfaces should• be easy to learn,• minimize user frustration • maximize user productivity

A few basic rules for the system requirements are:

• Software must assist the user perform a task, not become a task in itself

• Software must not make the user feel stupid

• Software must not make the computer appear to be stupid

Some of the important factors to be considered in the interface design are

• Visual elements – colors, fonts, icons etc.

• Terminology• Controls• Error messages• Metaphors

Visual Elements

When properly applied, color can • enrich the user interface by improving the

aesthetic quality of the interface• guide the user's attention to points of

interest.

The improper use of color on the other hand, can seriously impair the user's ability to interact with the program.

Icons

Terminology

Program developers and users should share the same knowledge base. Programs should be designed according to the tasks of the users and each should know what the other was talking about.

The designers of Netscape Navigator however, forgot that most people using their product are not programmers

In any other application cut =>object is removed and a copy is placed in the clipboard for later use

In Microsoft Excel, "Cut" means "Leave it there until I Paste it somewhere else."

ControlsIn a graphical user interface, the controls

represent the means by which the user communicates with the application. The quality of the communication depends on two aspects of the controls:

• the appropriateness of the control for the task • the consistency of the rules under which the

control operates. Selecting the wrong tool for the job, or changing

the rules under which the tool operates, the designer will create problems for the users.

Error MessagesError messages are often invasive and rude,

halting the current activity, and demanding that you acknowledge them before you are allowed to continue.

Many error messages are ambiguous, failing to provide meaningful information, and at times are simply incorrect, potentially causing undue grief and expense to the innocent user.

This message was popped up when trying to delete files from a nearly-full hard drive in Windows 95

Netscape's Hidden Frames function generates hidden messages as well.

Metaphors

Metaphors are often employed in interface design to help users learn the application by facilitating the transfer of existing knowledge

Good Design Features

Tool tips1) Enable users to learn the interface more

rapidly by making the toolbar less intimidating2) allow the user to rapidly locate functions that

may otherwise have been buried within the menus

Given all the passwords each of us must keep track of these days, it's all too easy to forget the password for a particular account or program