Task-Centered Walkthrough By Darren Andreychuk

What is a Task-Centered Walkthrough? A low-cost method of evaluating an interface early in its development Part of Task-Centered System Design

Task-Centered System Design Phase 1: Users and their tasks are identified Phase 2: Decide which users to include Decide which tasks to include Phase 3: Users and their corresponding tasks are merged with the system design -> scenario The goal is to tell a complete story

Task-Centered System Design Phase 4: Perform a task-centered walkthrough on each scenario

How The Walkthrough Works Choose a task scenario from the list of scenarios For each step in the task scenario do the following Can you build a believable story that will motivate the user’s actions? Can you rely on the user’s expected knowledge of the system to complete this step of the task? If you cannot answer yes to either of these questions then You have located a problem in the interface Note the problem and any comments, or possible solutions, that come to mind Once a problem has been identified, assume it has been fixed Proceed to the next step in the task scenario

Walkthrough Layout Scenario Title # Description of step Does the user have enough knowledge to carry out this step? Is the user motivated to do this step? Is it believable that they would do this? Comments (and possible solutions) 1. 2. .

When is the Algorithm Effective? When you place yourself in the mind of the user This must be maintained throughout each scenario When you run the walkthrough to completion Finish the walkthrough even if the design is really awful and needs to be re-done

When and Where? Task-centered walkthroughs are performed early in the design process Usually performed on throw-away paper prototypes before implementation even begins

Interface Design and Usability Engineering Articulate: who users are their key tasks Brainstorm designs Refined designs Completed designs Goals: Task centered system design Participatory design User-centered design Psychology of everyday things User involvement Representation & metaphors Graphical screen design Interface guidelines Style guides Participatory interaction Task scenario walk- through Evaluate tasks Usability testing Heuristic evaluation Field testing Methods: low fidelity prototyping methods high fidelity prototyping methods Products: User and task descriptions Throw-away paper prototypes Testable prototypes Alpha/beta systems or complete specification Greenberg, S. Overview of Task Centered Walkthrough

Benefits Good for locating bugs early in the design process Flexible Performed on throw-away paper prototypes Many problems can be located before implementation begins Flexible Can be performed by a single person or by a group of people on the design team Can involve actual users of the system earlier in the design process

Limitations Usually carried out in the same environment the system is being developed in Design team may not see the system run in the real-world If the walkthrough is performed as a group, it should progress at the same pace for all members Design teams can get stuck on a single step in a scenario because they are locked into a debate regarding a problem that they found This can disrupt the natural flow of steps in the scenario

Example: Management System The Situation Owner of Energy Lake System of Martial Arts needs a system that will assist him with the day-to-day affairs of his business Target user Owner of Energy Lake is a typical computer user Can access email, surf the web, etc. Task example Class cancelation

Example: Class Schedule Prototype

Example: Walkthrough Exercise Scenario 1: Last minute class cancelation # Description of step Does the user have enough knowledge to carry out this step? Is the user motivated to do this step? Is it believable that they would do this? Comments (and possible solutions) 1. Gary answers his phone in the studio. It is Paul phoning to cancel his class tomorrow. Yes 2. .

Task-Centered Walkthrough: Questions