User differences in interface design

TL;DR: The information systems profession has come to appreciate the importance of interactive interfaces that are tailored to distinct user characteristics, and software designers now recognize several dimensions in specifying user types for any information system, although they are still exploring the nature and interaction of those dimensions.

Abstract: The information systems profession has come to appreciate the importance of interactive interfaces that are tailored to distinct user characteristics. One measure of that progress is reflected in the content of recruitment ads for systems professionals. Only in recent years have employers requested \"user interface designers\" with expertise in the \"personalization of features in order to support a wide variety of user classes (casual to sophisticated) and the use ofanalogies to users' existing environment. \"I The implied single dimension of users-\"casual to sophisticated\"-is no doubt an ad writer's simplification of a more complex model. Software designers now recognize several dimensions in specifying user types for any information system, although they are still exploring the nature and interaction of those dimensions. Figure 1, a deliberately simplified model of human-computer interaction, shows the progression from user task to cognitive model of information system objects and facilities to selection of functions and commands. Physical communications to the information system are then carried out, and feedback from the system (state change message, error message, new prompt, etc.) is perceived and translated into a new action. For many purposes, of course, the function/command block must be further divided, and the task block can also be refined to consider the user's mental model of the task, as distinct from the task itself. The best systems expand the user task model to resemble the task more closely or even expand its boundaries; unfortunately, system-user interaction can also restrict real task boundaries or divert the task model from the actual problem. In evaluating user characteristics, we will consider three areas: (1) differences in the nature of the task to be performed and the associated mental task model, (2) differences in the nature and extent of the user's cognitive model of the information system, and (3) differences in the nature and extent of the user's exposure to the system. Obviously, the user's exposure to the system interacts with the first two, but only additional effects that are not clearly related to the other areas are considered part of user exposure. Task analysis The crucial role of requirements analysis in software engineering has become axiomatic. The same importance should be attached to task analysis for interface engineering , where the emphasis is on the nature of the activities that the information system will support, rather than on the specific processing functions to be developed. R. B. Miller addresses this perspective …