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.
How It Works
Participant Experience
Participant receives a WhatsApp message inviting them to take part.
They complete Activity 1 (e.g., a baseline survey).
After a defined delay (or immediately), they receive Activity 2 (e.g., a diary study).
After another delay, they receive Activity 3 (e.g., an AI interview).
On completion of the final activity, they receive a closing message.
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.
Setting Up a Multi-Day Study
Creating the Study
Click New Research.
Select Multi-Day Sequential Study.
Specify the number of days or activities in the study.
Choose the methodology for each activity: Survey, Diary Study, or AI Interview.
Configure each activity using the respective builder. See the Surveys, AI Interviews, and Diary Studies documentation for details on each builder.
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.
Immediate (no delay) — The next activity begins as soon as the participant completes the current one. Use this for activities that should flow back-to-back in a single session.
Hours — Short gaps for reflection or real-world experience between activities.
Days — Standard longitudinal spacing (e.g., Day 1, Day 3, Day 7).
Weeks — Extended studies tracking change over longer periods.
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
Survey → Diary Study → AI Interview Start with a survey to capture baseline data and classify participants. Use a diary study in the middle to track behaviours and collect media over time. Close with an AI interview to probe on patterns observed, explore motivations, and capture reflections.
AI Interview → Survey → AI Interview Open with an AI interview to explore initial attitudes and expectations. Follow with a survey to quantify specific behaviours after a trial period. Close with another AI interview to reflect on changes and overall experience.
Survey → Diary Study → Survey Open with a survey for pre-event attitudes and expectations. Use a diary study during the event for experience logging. Close with a survey for post-event recall and satisfaction measurement.
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.
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.
Known Limitations
Participant must complete current activity to progress — If a participant abandons an activity mid-way, the next activity will not trigger. Use reminders to re-engage incomplete participants.
Delay timing is from completion — The delay clock starts when the participant finishes an activity, not from a fixed calendar date. This means participants may be at different stages at any given 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.
Setup & Launch Timeline
Study structure and methodology selection: 30 minutes
Individual activity configuration: 1–3 hours per activity
Transition and delay settings: 15 minutes
Multi-language setup (if applicable): 30–60 minutes
End-to-end testing: 1–2 rounds recommended
Total time to launch: 3–5 days
Last updated