{
  "study_id": "NCT07611422",
  "agent": "baseline",
  "run": 2,
  "p_primary_hypothesis_supported": 0.15,
  "effect_direction": "null",
  "effect_size_90pct_interval": {"low": -0.2, "high": 0.45, "metric": "Cohen's d for positive-information vs neutral-information on PSS-10 at 4 weeks (positive = less stress with positive information)"},
  "moderator_prediction": "Slightly larger expectancy effect in the cold-shower arm, because a stress-resilience rationale is more credible and salient for a novel, effortful cold exposure than for routine warm showers; interaction itself unlikely to be significant at n=120.",
  "claim_ids_used": [],
  "rationale": "A one-time verbal rationale aimed at a 4-week trait-like self-report (PSS-10, one-month recall) in healthy volunteers is the weak case for expectation effects: the primer notes suggestion effects are large for acute outcomes but small for chronic ones weeks later, and OLP effects in non-clinical samples are about 0.29. Realistic d is roughly 0.1-0.2. With ~60 per expectancy level, power to detect d=0.2 is about 15-20%. Snowball sampling, low baseline stress (floor effects), daily diaries that may prompt reflection in all arms, and pre-registered-study base rates (~44%) further discount. Some upside from self-report and single-blind demand characteristics, and possible lenient reporting via interaction terms."
}