Primary Reference Source
Loucopoulos P and V Karakostas (1995) System Requirements Engineering. McGraw Hill International.
Observational methods involve an investigator viewing users as they work and taking notes on the activity which takes place. Observation may be either direct, where the investigator is actually present during the task, or indirect, where the task is viewed by some other means such as through use of a video camera.
Typical Application Areas
Useful early in specification for obtaining qualitative data. This method is an alternative (non-involving) version of Contextual Inquiry. It is useful for studying currently executed tasks and processes. It has been …show more content…
For this approach to be successful it is crucial that thorough pilot testing be conducted by the investigator before introducing users into the lab. This pilot testing has a number of steps:
1.The description of the tasks 2.A simple test procedure with written instructions 3.A predefined format to identify problems 4.A debriefing interview guide 5.A procedure to rank problems 6.An estimation of the proportion of problems identified (optional step)
If pilot testing is underestimated then results may be of little value. This planning will identify usability goals. Roles may then be distributed within the design team, and planning for the test can be administered. The number of subjects needed is then estimated, and a written procedure is made, with at least one pilot test being performed. Useful results can be obtained with three or four users; some data gathering techniques may need larger user sample sizes in order to minimize bias.
Using the test material, realistic scenarios will be recorded, along with demonstrations and instructions. After the session, data may then be collected from the subjects using interviews and questionnaires. Once trials are run, data is analyzed, metrics (if any) are calculated, and problem severity is prioritized in an implications report.