1. Task-Centered Walkthrough
By Darren Andreychuk

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

3. 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

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

5. 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

6. 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. .

7. 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

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

9. 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

10. 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

11. 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

12. 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 , surf the web, etc.
Task example
Class cancelation

13. Example: Class Schedule Prototype

14. 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. .

15. Task-Centered Walkthrough: Questions