City University Interaction Lab, CC-BY 2.0

Various methods and tools exist for testing the design of an existing or new product or service, such as usability testing (p.160) and contextual observation (p.50). It can be difficult, however, to gain a deep understanding of users’ interactions, and the reasoning that led to those interactions, purely from observing people interacting with a product or service. Methods such as interviews (p.92) and questionnaires (p.126) address this to some extent by asking people to verbalise their experiences. However, doing this retrospectively makes the accuracy and completeness of the information provided reliant on the user’s memory and ability to recall their interactions.

Continued on pages 158–159 of Design. Think. Make. Break. Repeat.