Participant Study

A practical entry point for real longitudinal follow-up.

This is the operational path for small participant studies around sleep, overnight physiology, next-day burden, and repeated daily self-report. It is designed to stay serious, lightweight, and compatible with the Butterfly Effect research stack.

Open daily check-in Open participant return Open institutional framing

What is captured

Passive signals plus daily labels

The study is not built on passive data alone. The important step is linking sleep and overnight physiology to repeated daily self-report.

  • Passive layer. Sleep timing, duration, continuity, heart-rate signal, HRV, activity, daylight, and related wearable measures when available.
  • Daily check-in. Short self-report on sleep quality, stress, anxiety, mood, fatigue, pain or tension, and a few key confounders like caffeine or alcohol.
  • Merge point. The final bundle is joined by participant identity and dates so the project can read night-to-day relationships within the same person.

Why this matters

It closes the main gap left by passive exports alone

Wearable exports are strong for pattern-tracking, but limited for symptoms and next-day burden unless daily labels exist. This study layer is what makes that linkage explicit.

  • Without daily labels. We can describe timing, short nights, or activated nights, but not defend strong symptom claims.
  • With daily labels. We can test within-person links such as short sleep to next-day stress, late nights to worse fatigue, or hyperactivation to a harder following day.
  • For the project. This gives Butterfly Effect its own longitudinal data path instead of depending only on outside cohorts.

Participant contract

The study is narrow on purpose.

  • Not diagnostic. The study does not diagnose insomnia, anxiety, depression, pain conditions, or any other disorder.
  • Longitudinal first. The unit of interpretation is repeated pattern, not one isolated night.
  • Research return. Outputs are designed to be understandable, but they remain governed research return rather than a consumer sleep app.

What participants receive

A serious return, not a wellness score.

  • Participant-facing monthly review. Clear explanation of the dominant sleep and physiology patterns in the follow-up window, with explicit limits.
  • Professional companion. Same core payload, but more structured for psychologist, clinician, or research review.
  • Evidence-backed orientation. Where relevant, the system can attach guidance tiers based on stronger vs weaker evidence rather than generic tips.

Operational tools

What participants can use right now

  • Daily participant check-in. Open the participant-facing check-in. It links the participant code to a secure study account, stores repeated check-ins in the study backend, and keeps progress visible without exposing export tools to the participant.
  • Participant experience stays focused. Export and support tools are kept out of the participant view so the daily task stays short, clear, and repeatable.
  • Study operations stay separate. CSV template, schema support, and local recovery tooling remain available for research setup, back-office use, or later merge with Apple Health history.

Privacy and operations

Pseudonymized study handling

  • Participant identity is separated. Contact details and analytical data should not live in the same operational layer.
  • Study data is linked by participant code. Daily check-ins, wearable exports, and generated reports all bind to the same governed participant identifier.
  • Scope remains academic and developmental. This infrastructure supports research, pilot studies, and methodological validation; it is not yet a clinical product.