Group Task Analysis Alfred Kobsa University of California, Irvine

How do users complete their tasks? (work flow) Users’ overall goals How they currently approach the task Information needed to achieve goals Interdependencies between steps Various outcomes and reports that need to be produced Criteria used to determine quality and acceptability of these results Communication needs of users as they exchange information with others Exceptions/emergencies and how to deal with them Users’ model of the task Problems they encounter What they like best / least What changes they would like Ideas for improvement

Pros and cons of using groups (as opposed to individual interviews) Pros: Describing procedural knowledge is difficult, but group situation may help People perform tasks differently and may have different views on what the process/policy is. Bringing them together helps build consensus Courage & Baxter: six times faster than individual analysis Cons: People may feel intimidated Consensus opinion may gravitate towards company norms, even though those do not reflect reality

Downsides of Group Task Analysis (specifically in comparison with field studies) Loss of context ( ☛ bring artifacts) Missed steps far less frequent than in individual analysis, but more than when observation takes place Stated versus actual behavior (Forgetting exceptions)

Elements of work flows Triggers End points Standard steps Decision points Sequence of steps Exceptions Steps that users dislike Additional information Actors

Elements of Group Task Analysis Tasks of interest Actors: participants, moderator, videographer, observers Activity material Canvas, steps on cardboards (self-adhesive), tape, … Users’ artifacts Video camera and audio recorder