Well-designed, surprising and playful materials can prompt participants to report in more lively and surprising ways than during interviews or focus groups, where they only sit and talk about their experiences. Probe studies provide participants with research materials they actively use for a certain period, and that trigger the recording of experiences during this use (e.g. notes, drawings, photos or audio recordings). For probe studies close collabaration between researchers and designers is crucial. This is an excellent method to actively involve members of design teams in the early explorations of a concept development process.
Diaries offer an excellent opportunity to document activities and experiences that take place on unpredictable moments or in private circumstances. In these situations direct observation is not a feasible option. As the research participants are asked to record their activities and reflections in a diary as soon as possible after they occur, the diaries provide reliable data with minimal intrusion. To optimally engage participants in the process of diary keeping, we have found that an ongoing contact with the researcher and an appealing design of the diaries are of crucial importance.