What needs to be finished first
A specific research question exists that requires temporal variation, longitudinal observation, or rare events and cannot be covered by a single interview.
Personas or user segments are defined, so recruitment can be targeted.
What needs to be ready before start
Diary template (digital, such as Indeemo, Dscout, or analog paper diary); event- or time-based prompt list; media capability (photo, video, voice); onboarding materials for participants; reminder mechanism (app push or calendar).
A lead researcher who designs the study, recruits participants, reviews entries, and asks follow-up questions; 5-15 participants willing to contribute daily; one study coordinator who manages reminders and incentive payouts.
Study purpose, duration (typically 1-3 weeks), effort per day (10-20 min), privacy, incentive amount, entry format; onboarding call with tool walkthrough.
2-4 weeks field phase, plus 1 week prep and closeout; 5-10 minutes per entry for participants
Prepare diary tool or template, define prompts per day or event. Recruit participants and confirm consent. Run a 3-day pilot with 1-2 people. Set reminder cadence and clarify the communication channel for questions.
The one question this method answers
What patterns, events, moods, or behavior changes become visible when participants document in a structured way over multiple days, information that a one-time interview cannot capture?
Marker: Phase
| Step | Duration | Action | Hint |
|---|---|---|---|
1Phase 1: Study design and pilot | 5-7 days | Translate the research question into prompts: daily, event-based, or snippet prompts. Select tool. Pilot with 1-2 people for 3 days to validate prompts and workflow. | Do not skip pilot phase. A frequent error is too many or too long prompts causing fatigue after day 3. The pilot reveals compliance risks before the main study. |
2Phase 2: Recruitment and onboarding | 3-7 days | Recruit participants (screen against persona criteria). Onboarding call of 30 min: tool walkthrough, expectations, privacy, incentive. Initial mini-task as a test. | Onboarding call must not be skipped. Participants who do not open the app independently in first 24 hours typically drop out early. Keep the first task low barrier. |
3Phase 3: Field phase | 1-3 weeks | Participants document by prompts. Researcher reviews entries daily or every two days, asks follow-up questions directly in the tool, motivates through dropouts, clarifies ambiguities. | Three days without researcher activity lowers participation. Follow-up questions are part of the method, not optional. Respond quickly to dropout or refill a slot. |
4Phase 4: Wrap-up interview | 30-60 min per person | After field phase, run one interview per participant: reflect on entries, close gaps, interpret patterns together, deepen contextual questions. | Wrap-up decides insight depth. Entries without an interview are often ambiguous. Schedule interview at end of field phase, not two weeks later. |
5Phase 5: Synthesis | 5-10 days | Extract themes, episodes, and mood trajectory per participant. Run affinity diagramming across participants. Derive patterns, outliers, and design implications. | Synthesis needs a second researcher. One researcher tags or reviews in parallel. Confirmation bias is especially strong with longitudinal data because there is a lot of material for selective interpretation. |
What comes out at the end
Chronological profile per participant with all entries (text, photo, voice), tags, and interpretations. Consolidated study report with themes, episodes, quotes, design implications, and outlier observations.
Per study, create a separate folder with date and research question in the header. Use participant pseudonyms; store identifiable data separately. Archive raw data; link synthesis to source quotes.
Compact working template for Diary Study with context, input, output artifacts, and next step.
Longitudinal method in which participants document experiences, tasks, or usage moments over time.
When and for what do we use this method?
Which data, observations, decisions, or materials are available?
Short notes along the runsheet.
Owner, date, and success signal.
Concrete filled scenario, fictional example
Concrete filled scenario, fictional example
Participants: 8 people, 14-day field phase. Compliance: 7/8 with more than 80% entries.
The planning tool must support the Sunday-evening rhythm rather than a weekday routine. Add historical data to improve travel-time estimates. Link the equipment list per assignment, not a static file.
Recognize symptoms and steer against them
Participants post heavily during days 1-5, then only sporadically, with gaps at the end.
Researcher engages actively with personalized follow-ups instead of automatic reminders. Pay incentives in milestones instead of only at the end. Reduce workload (1-2 prompts per day, not 5).
Entries are procedural logs ("8:00 woke up, worked at 9:00"), with no mood, no context, and no workaround information.
Use prompts that request tension or reflection: "What was surprising today?", "Where did you have an idea but not write it down?". Keep quantitative prompts to a minimum.
Wrap-up interview reveals gaps in entries that could have been clarified during the field phase.
Set daily or every-two-day review as a fixed routine. Ask follow-up questions directly at the entry in the tool. Budget review time realistically (15-30 min per day for 10 participants).
Synthesis is based only on entries, interpretations remain assumptions, participant has no validation.
Make wrap-up a required study part, not a discretionary add-on. Schedule wrap-up already during onboarding. Pay incentive only after full wrap-up.
Participants hesitate for photos or voice recordings, entries stay short, sensitive topics are omitted.
Document clearly in advance: who sees data, retention period, what pseudonyms are used. Show concrete examples of what goes into the report and what does not. Mark optional media explicitly.
One researcher synthesizes everything and themes reflect that person's assumptions.
Add a second person to synthesis, at least for cross-check. Perform affinity diagramming together. Compare codings and discuss differences explicitly.
Done signals checkable in under a minute
Go to the profile for purpose, similar methods, and sources or continue to the next method in the catalog.