Evaluation Method

Diary Study

A longitudinal research method in which participants record experiences, actions, contexts, or reflections over time.

Concept facts

A diary study is a research method in which participants record events, experiences, behaviors, or reflections repeatedly over a defined period.

Also known as
Diary method, experience diary, longitudinal diary, self-report diary, experience sampling study
Used in
Longitudinal UX research, service experience research, habit and routine analysis, product adoption, behavior tracking, repeated-use evaluation
Interpret with
Reporting frequency, participant burden, recall accuracy, time period, prompt design, context, missing data, and follow-up interviews

Plain-language explanation

A diary study asks participants to document experiences as they happen or shortly after they happen. The diary may be written, audio-based, photo-based, form-based, or app-based.

The method is useful when the research question involves repeated behavior, changing context, routines, waiting periods, interruptions, or experiences that are difficult to observe directly in one session.

For example, a diary study can show how people compare course options over several days, how they return to a service after receiving a message, or how they manage a recurring task.

Why it matters

Many UX and service experiences unfold over time. A single interview or usability test may miss what happens between touchpoints, after the first attempt, or during real-life interruptions.

Diary studies help capture patterns such as repeated confusion, delayed decisions, workarounds, emotional changes, follow-up actions, and changes in confidence.

They are especially useful when the experience is distributed across days, channels, devices, people, or institutional responses.

Use contexts

  • Longitudinal product research
  • Service journey research
  • Repeated-use behavior
  • Waiting and follow-up experiences
  • Habit and routine analysis
  • Multi-channel service use
  • Post-launch experience monitoring

Application guidance

Define the diary period, reporting frequency, prompt format, participant instructions, and expected data type before the study begins.

Keep participant burden manageable. Too many prompts can reduce data quality or cause dropout. Prompts should be clear and specific enough to produce useful entries without leading participants.

Use follow-up interviews or debrief sessions when possible. Diary entries often show what happened, while follow-up discussion helps explain why it happened and what it meant to the participant.

Practical example

A microfinance institution wants to understand how rural cooperative merchants use a mobile banking service across a 14-day repayment and cash-flow cycle.

A diary study asks participants to record when they check balances, manage delayed transactions, handle peer-to-peer transfers, respond to timeout errors, and seek help from agents or peers. The diary entries show that anxiety and support-seeking increase during settlement delays, leading the team to redesign transaction-state feedback and recovery messaging.

Interpretive boundaries

  • Diary studies rely on participant reporting.
  • Missing entries and delayed reporting can affect data quality.
  • The act of recording may change participant awareness or behavior.
  • Diary studies need careful prompt design and participant support.
  • Diary data should usually be interpreted with follow-up interviews or other evidence.

Applied at Userhub

Diary studies are relevant when Userhub investigates experiences that unfold over time, including learning decisions, service follow-up, product adoption, repeated tasks, and multi-touchpoint journeys.

See Userhub UX Lab for applied UX research and evaluation context.

Sources and references

  • Bolger, N., Davis, A., & Rafaeli, E. (2003). Diary methods: Capturing life as it is lived. Annual Review of Psychology, 54, 579–616. https://doi.org/10.1146/annurev.psych.54.101601.145030
  • Carter, S., & Mankoff, J. (2005). When participants do the capturing: The role of media in diary studies. Proceedings of the SIGCHI Conference on Human Factors in Computing Systems, 899–908. https://doi.org/10.1145/1054972.1055098
  • Rieman, J. (1993). The diary study: A workplace-oriented research tool to guide laboratory efforts. Proceedings of the INTERACT and CHI Conference on Human Factors in Computing Systems, 321–326. https://doi.org/10.1145/169059.169255
  • ISO. (2019). Ergonomics of human-system interaction — Part 210: Human-centred design for interactive systems (ISO Standard No. 9241-210:2019). International Organization for Standardization.

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Cite this entry

APA

Userhub. (2026). Diary Study. UX Reference. https://userhub.com.bd/reference/diary-study/