A group is a named subset of participants who receive notifications in lockstep. When a schedule targets a group, Samply fires the notification to every member at the same moment — a yoked design. This makes groups suitable for dyadic studies (couples, peers), team research, or any protocol where within-group synchronisation is essential. Each participant belongs to at most one group.
Creating a group
Groups must be created by the researcher before scheduling. Go to your study, open the Participants tab, and click Manage groups. Enter a group name and select participants from the list — only participants not already in a group appear. Click Create group to assign all selected participants at once.
Samply generates a short ID for each group automatically. This ID is used in the %GROUP_ID% URL placeholder and in the scheduled queue. The name is visible only to researchers in the dashboard; participants never see it.
Yoked timing
All members of a group receive the same notification at the same fire time. Samply writes one queue row per group at a shared Scheduled for timestamp and delivers it to every member simultaneously. There is no per-member offset within a group send.
For personal schedules (Day N after registration), Samply uses the join date of the most recently enrolled group member as the shared anchor. This means every member shares the same Day 1 regardless of when they individually joined — intentional for cohort designs where you want the group to move through the protocol together from a single reference date. If you need each participant on their own personal timeline, target them individually rather than as a group.
Targeting groups in a schedule
In Step 2 (Participants) of the schedule form, choose Groups as the audience and select which group or groups to target. Only participants assigned to the chosen group(s) at the moment you click Schedule notifications receive sends from that schedule. Participants who join the group later are included in subsequent sends — the group membership is re-evaluated at each fire time.
Deleting a group
Click Delete on the group row in the Groups tab. This clears the group assignment from every member — participants remain in the study and continue receiving any non-group-targeted notifications. They become eligible to be added to a new group.
Deleting a group removes the group assignment from every member. Pending notifications targeted at that group will not be delivered — at fire time, participants are no longer members of the group, so they are skipped.
Passing the group to your survey tool
Add %GROUP_ID% to your notification Web Link to include each participant's group in the survey URL automatically. Samply substitutes the four-character group ID at send time. If a participant has no group, %GROUP_ID% is left unreplaced — your survey tool receives the literal string, so handle this in your survey logic if group membership is not guaranteed for all participants.
See URL placeholders for the full list of available tokens and how substitution works.
Groups vs participant codes
- Use groups when
- You want yoked, synchronised sends to a cohort, or need to route different subsets to different notification schedules. Groups are first-class citizens in the schedule form and determine who receives which notifications.
- Use participant codes when
- You need to match Samply participants to records in an external system (REDCap record IDs, institutional IDs, pre-assigned codes). Codes are per-person identifiers, not grouping mechanisms. A participant can have both a code and a group.