Several comprehensive User Centred Design methodologies have been published in the last decade, but while they all focus on users, they disagree on exactly what activities should take place during the User Needs Analysis, what the end products of a User Needs Analysis should cover, how User Needs Analysis findings should be presented, and how these should be documented and communicated. This paper highlights issues in different stages of the User Needs Analysis that appear to cause considerable confusion among researchers and practitioners. It is our hope that the User-Centred Design community may begin to address these issues systematically. A case study is presented reporting a User Needs Analysis methodology and process as well as the user interface design of an application supporting communication among first responders in a major disaster. It illustrates some of the differences between the User-Centred Design and the Requirements Engineering communities and shows how and where User-Centred Design and Requirements Engineering methodologies should be integrated, or at least aligned, to avoid some of the problems practitioners face during the User Needs Analysis.

A technique that measures the impact of command selection on task time and errors is described. Users were timed while performing a drawing task, then while performing the same task with interpolated command selections. The difference between these times, consisting of both the time to select the command and to resume drawing, is the time cost of command selection. Several interface configurations were evaluated with this method including selected combinations of single mouse, two mice, voice and touch. Touch and voice input resulted in faster command selection times (approximately 1 sec) than any of the mouse conditions (approximately 3 sec).

The effect of video display unit presentation rate on reading performance was investigated. Reading material was presented at one of the following presentation-rates: 15, 30, 120, 960 cps, or “instant”. In the instant condition, the full text appeared simultaneously on the screen. In the other conditions, text appeared one character at a time starting in the upper left corner of the screen, from left to right and top to bottom. Reading comprehension was highest under the 30 cps and instant presentation conditions. Total time to perform the reading task was equivalent for all conditions except the 15 cps rate which required a longer time to complete the task. In terms of comprehension and time to perform the task, a slow rate of 15 cps, contrary to previous recommendations, is not desirable for novice computer users.