Glossary
Diary study
What is a diary study?
A diary study is a longitudinal research method where participants self-report their experiences, behaviors, and thoughts over an extended period, typically days or weeks, using structured prompts.
How it works
Participants record entries at scheduled intervals, after relevant events (event-contingent recording), or in response to prompts. Reporting near the event can reduce dependence on distant recollection, but records remain self-reports. Missing entries, reporting burden and changes caused by monitoring can affect the findings. Diary studies can examine product use, routines and experiences over time. Analysis can combine patterns across entries with qualitative themes in participants’ descriptions.
Applied example
A fitness-app team could ask new users to record when they use the app and what helps or prevents use. One participant might report opening the app during a lunch break but forgetting it on busy days. Such entries help the team investigate context; they do not establish why engagement changed on their own.
Why it matters
Diary studies add repeated, contextual accounts to short research sessions. Their quality depends on suitable prompts, participant follow-through and careful interpretation.
Kim Flaherty’s guide describes how to plan and conduct a diary study. Remember that a diary records what participants report, which may differ from a complete record of their behavior.