Multi-Day Studies in Yazi
Overview
A multi-day study links multiple research activities into a single sequential experience for the participant. Each activity can be a different methodology — a survey on Day 1, a diary study on Day 2, an AI interview on Day 3 — all connected within one WhatsApp conversation.
This allows you to design structured longitudinal research where the questions evolve over time, combining different methods at different stages to capture a complete picture.
At a Glance
Best for: Longitudinal research with multiple stages
Typical structure: 2–7 linked activities
Methodologies supported: Survey, Diary Study, and AI Interview
Best output: Connected data across multiple days or moments
Best use case: Before / during / after journeys
Use a multi-day study when your research needs to change over time. Use a diary study when you need the same recurring questions over time.
How It Works
Participant Experience
From the participant's perspective, it feels like a single ongoing study that unfolds over time — not three separate surveys. Everything happens in the same WhatsApp chat.
Example: Young Adults & Social Media Study
Day 1 — Survey: Baseline questions about social media habits, platforms used, daily screen time.
Days 2–5 — Diary Study: Participants log their social media sessions as they happen, capturing what they saw and how they felt.
Day 6 — AI Interview: The AI explores patterns from the diary entries, probing on motivations, emotional responses, and behavioural triggers.
When to Use Multi-Day Studies
Multi-day studies are the right choice when your research requires different methodologies at different stages, or when you need questions to evolve over time.
Before / during / after — Baseline survey → product trial diary → post-trial interview.
Onboarding journeys — Day 1 first impressions → Day 3 usage patterns → Day 7 overall experience.
Evolving research questions — Broad survey to categorise → diary to observe → interview to understand.
Campaign tracking — Pre-campaign attitudes → daily exposure logging → post-campaign recall.
Longitudinal health studies — Initial health assessment → daily symptom diary → follow-up interview.
Event-based research — Pre-event expectations → during-event experience diary → post-event reflection.
Key distinction from diary studies: A diary study repeats the same questions over time. A multi-day study changes the questions — and even the methodology — at each stage. Use a diary study to capture recurring behaviours. Use a multi-day study to guide participants through an evolving research journey.
Diary Studies (Longitudinal & recurring questions)Setting Up a Multi-Day Study
Creating the Study
You can mix methods freely across the sequence. For builder details, see:
Upload Brief with AI
You can use the Upload Brief with AI method to generate your multi-day study:
Upload your research brief.
Specify the number of days.
Select the methodology type for each day.
The AI generates a draft question set for each activity.
Edit and refine in the builder.
This is particularly useful for complex multi-day designs where you want a starting framework to iterate on.
Controlling the Flow Between Activities
Transition Settings
Between each activity, you control how and when the participant moves to the next stage. Click the transition button between activities to configure the delay.
Tip: Match your delay to the behaviour you're studying. If you need participants to experience something in the real world between activities (e.g., use a product, attend an event), build in enough time for that to happen naturally.
Mixing Methodologies
The power of multi-day studies is the ability to use different methodologies at different stages. Each activity in the sequence is configured independently using its own builder.
Common methodology combinations
Start with a survey to capture baseline data and segment participants. Use a diary study to capture behaviour and media over time. Finish with an AI interview to probe on patterns and motivations.
Start with an AI interview to explore expectations. Follow with a survey to quantify what happened. Finish with another AI interview to reflect on change.
Use a survey for baseline attitudes. Use a diary study during the experience. Use a final survey for post-event recall and satisfaction.
There are no restrictions on which methodology you use at each stage. You could run three surveys, three AI interviews, or any combination.
Multi-Language Support
Language settings are configured once at the study level and apply across all activities in the multi-day study:
Participants select their preferred language once at the start.
All activities — surveys, diary studies, and AI interviews — render in the chosen language.
You don't need to configure translations separately for each activity.
Results are translated back to your primary language consistently across all stages.
To set up translations, go to Study Settings and add your target languages. The translations will be applied across every activity in the study.
Multi-Day Study Design Best Practices
Activity Sequencing
Start structured, end open. Begin with a survey to capture baseline data, then use a diary or AI interview to go deeper. The structured data from early activities gives context for later qualitative exploration.
Build on previous activities. Design each activity to reference or build on what came before. If the AI interview is the final stage, it can draw on survey responses and diary patterns to ask more targeted questions.
Don't front-load effort. If Day 1 is too long or demanding, participants won't return for Day 2. Keep the opening activity short and engaging to establish momentum.
Managing Participant Drop-Off
Drop-off between activities is expected in any multi-day study. Design accordingly:
Keep the first activity the shortest and easiest.
Place your most critical research questions in the earliest activities.
Use broadcast reminders between activities to re-engage participants.
Set delays that feel natural — too short feels pushy, too long and participants forget.
Timing Considerations
Weekday vs. weekend: Consider when your participants are most available and engaged.
Time of day: Schedule activity triggers for times when participants are likely to be responsive.
Study duration: Longer studies require stronger incentive structures and more frequent reminders to maintain engagement.
Keep the first activity short. If Day 1 feels heavy, many participants will never return for Day 2.
Data Structure
Each activity in a multi-day study generates its own dataset, but all activities are linked by participant identifier. This means survey responses from Day 1, diary entries from Days 2–5, and AI interview transcripts from Day 6 are all connected to the same participant.
You can analyse each activity independently or combine data across activities for longitudinal analysis. Diary study activities generate multiple rows per participant (one per session), while surveys and AI interviews generate one row per participant.
This structure lets you analyse each stage separately or stitch them together into a participant journey.
Known Limitations
Known limitations
Participants must complete the current activity to progress — If they abandon a stage, the next one will not trigger.
Delay timing starts from completion — Participants can be at different stages at the same time.
Sandbox Testing
Build and test your full multi-day study in the sandbox before going live:
Test each activity independently to verify questions and logic.
Test the full sequential flow including transitions and delays.
Verify that methodology switches (e.g., survey → diary → AI interview) work seamlessly.
Confirm multi-language settings apply across all activities.
All content carries over when you launch with your dedicated number.
Test both the individual activities and the full end-to-end sequence. Transition timing is just as important as question logic.
Setup & Launch Timeline
Typical total time to launch: 3–5 days
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