What problem does it solve?
This Skill helps you avoid underpowered or overpowered psychological studies by computing the sample size, achieved power, minimum detectable effects, and power for common statistical tests and complex designs.
Core Features & Use Cases
- A priori, post-hoc, and sensitivity power for t-tests, one-way ANOVA, correlations, and logistic regression using Python.
- Effect-size-first workflows using common measures (e.g., Cohen’s d, f, r) and conversions to power-ready inputs.
- Simulation-based power for mixed (between-within) ANOVA and mediation indirect effects, including sequential/alpha-spending planning.
Use cases:
- Design an RCT in clinical psychology by determining the per-group N needed to reach 80% power at α=0.05 for a hypothesized standardized effect.
- Estimate mediation power via Monte Carlo simulation when indirect effects are the primary target.
- Create power curves and sequential testing boundaries to support study planning and adaptive designs.
Quick Start
Use the power-analysis skill to compute the required per-group sample size for a two-sided two-sample t-test with effect_size d=0.55 at alpha=0.05 and power=0.80.