Instructor: Sheelagh Carpendale
CPSC 481: Foundations of Human Computer Interaction
Fall 2002
Notes Section #2

Task-Centered System Design

Task-centered system design, a variation of user centered design, is a technique that allows developers to design and evaluate interfaces based on users' real-world tasks. As part of the design, it becomes a requirements analysis (with the requirements being the tasks that need to be satisfied). As part of evaluation, the evaluator can do a walk-through of the prototype, using the tasks to generate a step by step scenario of what a user would have to do with the system. Each step in the walkthrough asks the questions: is it believable that a person would do this; and does the person have the knowledge to do it? If not, then a bug has been found.

An assignment on task-centered design and prototyping  provides students with hands-on practice in task articulation and prototype walkthrough.



Topics covered

Required Readings

Optional Readings from Baecker Grudin Buxton and Greenberg

In-class teaching tips

I develop an example of task-centered system design by using an imaginary client called "Cheap Shop", a catalog-based store. The situation is that Cheap Shop's customers now browse through paper catalogs and then place their orders by filling in a form and giving it to the clerk. Cheap Shop is considering replacing the paper forms by a computer interface. An initial design is proposed (provided in the exercise mentioned above). The task examples presented in the exercise are used to develop usage scenarios. The class then evaluates the design by a walking a user through the example tasks step by step. Of course, many deficiencies are discovered.

Major sources used to prepare lecture material