Task Scenario
A group of friends shares expenses during a meal. Each person sometimes pays the total bill. The task is to identify who paid each expense accurately and efficiently.
Norman, GOMS & KLM – Who Paid Task Analysis
| Stage | User Action | Norman | GOMS / KLM Interpretation | Analysis |
|---|---|---|---|---|
| Goal | User wants to know who paid the bill | Form Goal – User defines intention to identify payer | Goal = Identify payer | ✅ All models align; Norman focuses on cognition, GOMS defines task goal |
| Plan / Decision | User decides to check app or receipt | Form Intention – Decide how to obtain payment information | Method selection – Open record then select expense | 🟡 Norman highlights mental planning; GOMS emphasizes method choice |
| Target Identification | User visually searches for correct expense or person | Specify Action – Decide which item to select | KLM Mental operator [M] for visual search | ⚠️ Norman models perception; GOMS assumes target is already known |
| Execute | User selects the expense entry | Execute Action – Perform selection | Operator = Tap; KLM sequence M → P → K | ✅ Physical action captured clearly; time measurable using KLM |
| Perceive | User reads payer name and amount | Perceive System State – Observe displayed information | KLM Read operator [R] | Norman explicitly models perception; GOMS treats it implicitly |
| Interpret | User compares shown payer with memory or expectation | Interpret System State – Make sense of information | Mental operators – Recall and Compare | Strong overlap between Norman cognition and KLM mental actions |
| Evaluate / Feedback | User confirms who paid | Evaluate Outcome – Check if goal is achieved | Feedback not explicitly modeled | Norman addresses Gulf of Evaluation; GOMS/KLM largely ignore feedback |