Privacy
Cluster is designed to index anonymous results for aggregate analysis without creating accounts or collecting names.
Stored data
V1 stores an anonymous session ID, item responses, computed scores, completion time, survey version, validity flags, and optional coarse demographic buckets if added later.
Not stored
V1 does not require name, email, phone number, account login, payment details, or free-text personal history.
Research use
Anonymous responses may be used to improve scoring, run aggregate meta-analysis, and build better norms. Public result pages expose computed results only, not raw item responses.