{
  "study_id": "NCT07611422",
  "agent": "framework",
  "run": 5,
  "p_primary_hypothesis_supported": 0.25,
  "effect_direction": "favours intervention",
  "effect_size_90pct_interval": {"low": -0.2, "high": 0.55, "metric": "Cohen's d, positive-information vs neutral-information on PSS-10 at 4 weeks (positive = less stress with positive information)"},
  "moderator_prediction": "Cold-shower participants respond more to positive information: the cold is an arousing bodily render each morning that the rationale gives meaning to, and the rationale fits a widely held belief about cold exposure; a stress-reducing rationale for warm showers is less compatible and has no impactful render to attach to.",
  "claim_ids_used": ["PM-0056", "PM-0128", "PM-0113", "PM-0107", "PM-1353", "PM-0102", "PM-0137", "PM-0218", "PM-0946", "PM-1286"],
  "rationale": "The expectancy manipulation is a single spoken rationale to alert participants: one small deposit that pays the normal tax. It does get repeated through the daily shower and diary, and PSS-10 is a self-rated felt state, so some effect is expected, probably favouring positive information. But PSS-10 measures global life stress over the past month, and ordinary days contradict it, so the effect should be small. With about 60 per expectancy arm, a d near 0.2 is underpowered. The cold-shower rationale should work better (arousing bodily render, compatible prior), but that only helps the interaction. Snowball recruitment adds noise. Significance at 4 weeks is unlikely."
}