Home

>

Knowing the User and his Tasks

There is no such thing as the "typical" user (Shneiderman 18-19). Problems are solved in different ways by different people. As a result, different personality types should be taken into account when designing a system, using psychological scales such as pointed out by Shneiderman (23-25).³⁹ Unfortunately, there is little documentation dealing with basic problems, e.g. the differences between female and male users (23). For example, commands such as "abort" and "kill" may have a different connotation for women.

Apart from these differences, users are often differentiated into:

• novice users,
• casual users,
• intermediate users,
• and experts (also known as "power users").

In order to meet the needs of these different groups, a system should allow a level-structured approach (Benning Der Nutzer, das unbekannte Wesen 106-107; Shneiderman 55; Microsoft 15). This approach is also called the 80 percent solution (Apple Computer Macintosh Human Interface Guidelines 35).

The user profile is strongly connected to the task profile which has to be analyzed before the design of an application can start (Shneiderman 55). Users have goals and subgoals, and they perform tasks which can be divided into middle-level task actions and further differentiated into atomic actions (see section 3.2.3). The approach of determining user tasks is called user-centered or task-centered design.

>

> _uacct = "UA-276221-6"; urchinTracker();