Diary Studies (Longitudinal & recurring questions)
Overview
Yazi diary studies allow participants to log activities, experiences, or behaviours repeatedly over a longitudinal period — all within WhatsApp. Rather than answering a survey once, participants return to the same conversation to record entries whenever a relevant event occurs, building a rich picture of their habits and routines over days, weeks, or months.
Each entry is logged as a separate session, creating a timestamped dataset that shows patterns, changes, and trends over time.
Diary Studies on Yazi
Overview
Yazi diary studies allow participants to log activities, experiences, or behaviours repeatedly over a longitudinal period — all within WhatsApp. Rather than answering a survey once, participants return to the same conversation to record entries whenever a relevant event occurs, building a rich picture of their habits and routines over days, weeks, or months.
Each entry is logged as a separate session, creating a timestamped dataset that shows patterns, changes, and trends over time.
How It Works
Participant Experience
Participant receives a WhatsApp message inviting them to join the diary study.
They tap a button to begin.
A menu appears listing the types of activities they can log.
The participant selects the relevant activity.
A short set of questions is asked about that specific activity.
On completion, the participant is routed back to the menu.
They can log another entry immediately or return later to log again.
The conversation stays open indefinitely. Participants can come back at any time — when they next experience the behaviour you're tracking — and start a new entry from the menu. Each completed loop is logged as a separate session in your results.
Chat Pinning
Participants can pin the diary study chat to the top of their WhatsApp conversation list, keeping it permanently visible. This is particularly effective for diary studies where you need participants to remember to log entries throughout the day — the study is always the first thing they see when they open WhatsApp.
Tip: Include an instruction in your introductory message asking participants to pin the chat. This simple step significantly improves engagement and logging frequency.
Example: Social Media Usage Diary
Menu appears: "What would you like to log?"
Social media scroll
End of day reflection
Participant selects: "Social media scroll"
Questions asked:
Which social media channels were you on?
What did you do there?
How long did you spend scrolling?
Did you see any content that made you stop and engage?
On completion: Participant is routed back to the menu and can log another session or come back later.
When to Use Diary Studies
Diary studies are the right methodology when you need to capture behaviour as it happens, track patterns over time, or understand routines that unfold across days, weeks, or months.
Behaviour tracking — Daily food intake, exercise habits, medication adherence.
Experience logging — Customer service interactions, product usage moments, shopping trips.
Media capture — Screenshots of ads encountered, photos of meals, videos of routines.
Mood & wellness — Daily mood check-ins, symptom tracking, energy levels.
Travel & commuting — Transport choices, travel ad exposure, booking behaviour.
Product trials — Longitudinal feedback during a product test period.
Work routines — Creative tool usage, AI integration habits, daily workflows.
Key distinction from surveys: A survey captures a single snapshot. A diary study captures a pattern over time. If you need to understand what happened once, use a survey. If you need to understand what keeps happening, use a diary study.
The Diary Study Builder
Menu Structure
The diary study builder is similar to the survey builder, with one critical difference: the first question is a menu that serves as the participant's home screen.
The menu lists the different types of activities or events the participant can log. Each menu item routes to a different set of questions — a different journey through the diary.
For example:
Menu item 1: "Social media scroll" → routes to questions 2–5
Menu item 2: "End of day reflection" → routes to questions 6–10
Menu item 3: "Ad I saw today" → routes to questions 11–14
Each journey ends by routing the participant back to the menu, ready to log the next entry.
Defining Journeys with Routing Logic
Each menu item triggers a different question pathway using the same routing logic available in standard surveys:
Branching from the menu — Each menu option directs the participant to a specific question in the survey.
Sequential questions within a journey — Questions flow in order within each pathway.
Return to menu — The final question in each journey is marked as "survey complete," which logs the session and routes the participant back to the menu.
Nested logic within journeys — You can add further branching within a journey based on participant responses (e.g., different follow-ups depending on which social media platform they used).
This allows you to build complex diary structures with multiple distinct journeys, all accessible from a single menu.
Session Logging
Every time a participant completes a journey (reaches a question marked as "survey complete"), it is recorded as a separate session. For example:
Participant logs a social media scroll at 9am → Session 1
Participant logs another scroll at 2pm → Session 2
Participant logs an end of day reflection at 9pm → Session 3
Each session appears as a separate row in your results, timestamped and linked to the participant. Over the course of a study, a single participant may generate dozens of sessions.
Setting a Session Limit
You can define a maximum number of entries per participant. Once they reach the limit, the diary study closes for that participant. This is useful for controlling data volume, ensuring participants don't over-log trivial entries, and aligning with incentive structures tied to completion targets.
Custom Messages
Configure custom messages for key moments in the diary flow:
Session start message — Instructions or reminders shown when the participant begins a new entry.
Session complete message — A thank-you or acknowledgement after each logged entry.
Study complete message — A closing message when the participant reaches their session limit or the study period ends.
These messages help maintain participant engagement and set expectations throughout the study.
Question Types
Diary studies support all the same question types as standard surveys: Single Select, Multi-Select, Open Text, Rating Scale, Voice Note, Image Upload, Video Upload, Location, and File/Document. All builder features — text formatting, live preview, validation warnings, option randomisation, and the "Other" toggle — work identically to the survey builder. See the Surveys documentation for full details on question types.
Scheduled Reminders
While participants initiate each diary entry themselves via the menu, you can set up broadcast reminders to prompt them to log:
Time-based frequency — Send reminders daily, weekly, or at any custom interval.
Condition-based — Trigger reminders only for participants who haven't logged an entry within a specified period.
Custom messaging — Tailor reminder content to reinforce the study purpose and maintain motivation.
Reminders are configured in advance and run automatically for the duration of the study.
Diary Study Design Best Practices
Keep Each Journey Short
Each logging session should take 2–5 minutes at most. Participants are logging entries multiple times — sometimes multiple times per day. Long question sets per entry will cause fatigue and abandonment.
3–6 questions per journey is the sweet spot.
Front-load the most important question in each journey.
Use media capture (photos, voice notes) instead of lengthy open-text questions for richer data with less typing effort.
Design the Menu for Clarity
The menu is the participant's primary interface with the study. It should be:
Exhaustive — Cover all the activities or events you want captured.
Mutually exclusive — Each menu item should represent a clearly distinct activity so participants don't hesitate about which to choose.
Simply worded — Use participant language, not research terminology.
Limited to 3–6 items — Too many options creates decision fatigue.
Consider the Logging Trigger
Think about when and why participants will log entries, as this shapes your study design:
Event-based logging (e.g., "Log every time you see a travel ad") — The participant initiates at the time of the event. Keep questions very short so they can log in the moment.
Time-based logging (e.g., "Log your meals at breakfast, lunch, and dinner") — Use scheduled broadcast reminders to prompt entries at the right times.
End-of-day logging (e.g., "Reflect on your day before bed") — Include an "End of day" menu option with slightly longer reflection questions.
Combination logging (event logging throughout the day + end of day summary) — Use multiple menu items serving different purposes, with different question depths for each.
Plan for Partial Data
Not every participant will log every day. Not every entry will be complete. Design your study to be valuable even with gaps:
Capture the most critical data point in the first question of each journey.
Use scheduled broadcast reminders to prompt participants who haven't logged recently.
Accept that diary data is inherently messier than survey data — the richness comes from patterns across entries, not perfection in any single one.
Diary Studies vs. Multi-Day Studies
Yazi supports two approaches to longitudinal research, and they serve different purposes:
Diary Studies are participant-initiated. Participants log entries when the event happens, answer the same questions each session, and have high control over when and how often they log. Diary studies are best for capturing in-the-moment behaviours and experiences.
Multi-Day Studies are researcher-initiated. Questions are sent at predefined intervals (Day 1, Day 3, Day 7), with different questions on different days and low participant control over timing. Multi-day studies are best for structured longitudinal tracking with evolving questions.
You can combine both approaches: use a diary study for ongoing event logging, and layer scheduled broadcast messages on top for specific daily tasks or check-ins.
Common Diary Study Structures
Simple Recurring Log
A single menu item with 3–5 questions per entry and unlimited entries over the study period. Works well for daily mood tracking, medication adherence, or any single behaviour you want to track repeatedly.
Multi-Activity Log
3–5 menu items, each with its own question pathway. Participants choose which activity to log each time. Works well for studies like creative tool usage diaries (AI tools, design software, writing tools) or multi-channel shopping behaviour.
Activity Log + Daily Reflection
Menu items for in-the-moment logging throughout the day, plus an additional "End of day" menu item with broader reflection questions. Works well for studies like social media usage (log each session during the day) combined with an end of day summary (overall screen time, how they felt about their usage).
Product Trial Diary
Structured around product usage occasions, with media capture (photos/videos of the product in use) as core data. Often combined with scheduled broadcast reminders to prompt regular logging. Works well for new product trials tracked over multiple weeks — for example, a new skincare product trial over 4 weeks.
Multi-Language Support
Diary studies support the same multi-language functionality as surveys and AI interviews. Write all questions and menu items in your primary language, auto-translate into target languages with manual editing, and participants select their preferred language at the start. All entries are captured in the original language and translated back. The menu, all journey questions, and custom messages are all translated.
Known Limitations
Menu display — The menu renders as a WhatsApp list (scrollable via burger menu button). Keep menu items concise so they're scannable at a glance.
Session data structure — Each session creates a new row in your results. For participants who log many entries, this can generate large datasets. Plan your analysis approach accordingly.
Sandbox Testing
Build and test your full diary study in the sandbox before going live:
Test each menu journey end to end.
Verify that session logging works correctly (each completed journey should create a new entry).
Confirm routing returns participants to the menu after each journey.
Test the experience of logging multiple entries in a row.
All content carries over when you launch with your dedicated number.
Setup & Launch Timeline
Menu and journey configuration: 1–3 hours depending on complexity
Routing logic setup: 30–60 minutes
Testing all journeys: 1–2 rounds recommended
Total time to launch: 2–4 days
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