User-Centred Requirements Handbook |
| 3.11.1 Usability test plan | |
| User sample and characteristics | Include equal numbers of males and females in user trials 1.3.2 |
| Method of recruitment | Advertise for bank machine users through local newspapers. |
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Tasks or Scenarios Based on Form 1.7 user goals or Form 2.3 Task scenarios |
S1(1) Access bank machine and withdraw £50 in cash and collect receipt. S2(1) Access bank machine and withdraw £200 when limit £50 S3(1) Access bank machine, request £100 then stop transaction S8(4) Access bank machine and request £100. Report that incorrect amount dispensed. |
| Measures/Method of data capture |
Task achievement. - Observation Time to complete task. - Observation/stop watch Comparison with expert user - Video analysis Comments pre and post system. - Interview Ratings of ease /difficulty of task. - Survey form and prompt cards |
| Test equipment |
Panasonic 9000 video recorder. Panasonic video camera. Notepads and pens. Stopwatch. |
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Environment based on Forms: 1.4 Technical environment 1.5 Physical environment 1.6 Social and organisational environment |
Simulation of bank foyer. Bank machine set-up which user interacts with. Desk manned by member of bank staff (experimenter) who will provide support as required. |
| Introduction to subject |
Brief introduction to the new bank machine. Five minutes of guided practice exploring the basic facilities. |
| Assistance to be given | No help to be given unless the user is unable to proceed. |
Form 3.11.2 - Usability test results (Example)
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3.11.2 Usability test results Results based on user test with of 20 bank customers. |
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| Tasks | Task achievement | Mean Time and Standard deviation | Comparison with expert task time | Subjective rating of difficulty (1=easy 7=difficult) | Comments |
| S1(1) Withdraw £50 | 80% |
Mean: 4 mins SD: 25secs |
75% | 2.2 | All users carried out task fairly easily. |
| S2(1) Withdraw amount> cash limit | 90% |
Mean: 3 mins ,DT>SD: 45 secs |
60% | 4.6 | Some users not sure of level of cash limit. |
| S3(1) Access bank machine then halt transaction | 60% |
Mean: 2 mins 30 sec SD: 15 secs |
75% | 3.2 | Most users able to exit easily. Some users expected quit key to be red not yellow. |
| S8(4) Access bank machine and report incorrect money dispensed. | 80% |
Mean: 8 mins SD: 15 secs |
75% | 6 | Most users unsure how to report this problem through the machine. Most reported problem to member of bank staff. |