You can design a study with multiple phases (for example, a 1-week pre-treatment phase, a treatment phase, and a 1-week post-treatment phase) by combining participant variables, criteria, and triggering logics. This guide shows a simple setup you can reuse.
The Situation
You want a study with three distinct phases:
- Phase 1: 1 Week Pre‑Treatment
- Phase 2: During Treatment
- Phase 3: 1 Week Post‑Treatment
Each phase should display the appropriate activities at the right times, and transitions between phases should occur according to your study rules.
What to Do?
1. Define a participant variable for the study phases.
-
Add a Multiple Answer Question named Participant’s Study Phase with the following values:
- Pre
- During
- Post
-
Next, proceed to initialize participants to Pre for the pre‑treatment phase by submitting a session through Activity Session tab.
-
Make sure to note the question ID (for example,
Q27283_1), as it will be required in the next step.
2. Set the criteria.
-
Navigate to your Phase-Based activity.
-
Go to the Triggering Logics tab.
-
Select the User Triggering Logic.
-
In the criteria field:
- For Pre-treatment activities use:
Q27283_1 == 1 - For treatment activities use:
Q27283_1 == 2 - For Post-treatment activities use:
Q27283_1 == 3
- For Pre-treatment activities use:
-
Click Save.
-
Save and publish the activity.
3. Move participants between phases.
-
Update the Participant’s study phase variable via Activity session to control transitions.
- Start of Treatment: set the variable to During
- After Treatment: set the variable to Post
-
Test the setup to verify the final result.
Pro Tip
When designing multi-phase studies, clearly define the transition rules between phases and ensure participant variables are updated consistently. This helps ensure that participants see the correct activities at the appropriate time and reduces confusion during phase transitions.