Applicable stage(s): design.
Personnel needed for the evaluation: Usability experts: 1 Software developers: 1 Users: 2	Usability issues covered: Effectiveness: Yes Efficiency: No Satisfaction: Yes
Can be conducted remotely: No	Can obtain quantitative data: No

 Overview

At the design stage, when paper prototype is available, a group of users, developers, and huaman factors engineers meet together to step through a set of tasks, discussing and evaluating the usability of a system. Group walkthroughs have the advantage of providing a diverse range of skills and perspectives to bear on usability problems. As with any inspection, the more people looking for problems, the higher the probablility of finding problems. Also, the interaction between the team during the walkthrough helps to resolve usability issues faster.

Form the Walkthrough Team

Three types of participants are included in the walkthrough: representative users, product developers, and human factor engineers. One coordinator is needed and the role is usually played by a human factors engineer. Participants, except the coordinator, are all asked to assume the role of the user during the walkthrough.

Materials

Paper prototype of the interface are to be used for the walkthrough. Hard-copy panels of screens, dialog boxes, menus, etc. will be presented in the same order in which they would appear online for each task.

Walkthrough the Tasks

For each step,

• All participants are presented with the interface design in the form of a screen panel and asked to write down separately the action they want to take. The participants need to write their actions in as much detail as possible, down to the keystroke (or other input action) level, e.g. "Press the down arrow key three times, then press 'Enter'".
• After all participants have written the actions they would take for the task, a discussion begins, in which the users speak first. Only when the users' comments are exhausted do the usability experts and the product developers offer their opinions.
• After the discussion, the coordinator will tell the participants what actions they are supposed to take according to the user interface design and present the new screen panel after the actions. Thus the walkthrough moves to the next step.

1. R. Bias "The Pluralistic Usability Walkthrough: Coordinated Empathies:, in J. Nielsen & R. Mack "Usability Inspection Methods", Chapter 3, pp.63-76, John Wiley, 1994.