Cognitive factors in user classification

Although one of the common recommendation given to interface designers is that they should know the user, user classification is difficult to achieve. Different classifications, such as experience, attitude, occupation, and cognitive style have been attempted to classify the users. Part of the difficulty in user classification stem from the facts that a) the systems are complex, and b) the range of users are diverse and varied. Even more confusing is the fact that 'how does one use the user knowledge in the design process?' This presentation will discuss the use of cognitive factors in predicting individual differences amongst users, and in developing user behavior model. A current case history will be discussed. The merits of psychometric factors, and personality factors in enumerating user differences will be addressed, as will be the need for developing better cognitive design factors.