running-power-analysis

Calculate sample size, power, or minimum detectable effect for planned statistical tests.

2|Updated May 23, 2026
One-click install
npx skills add https://github.com/rocklambros/rcs --skill running-power-analysis
Or copy as Structured Prompt for Agent▼
Please help me install this Agent Skill.
Skill: running-power-analysis
Source: https://github.com/rocklambros/rcs/tree/main/skills/ml-datasci/running-power-analysis
Command: npx skills add https://github.com/rocklambros/rcs --skill running-power-analysis

SYSTEM DOCUMENTATION & REQUIREMENTS

💡 This Skill includes references (resource) components.

What problem does it solve?

This Skill helps you plan a study before data collection by turning a test choice, an expected or minimum meaningful effect, and a target alpha/power trade-off into a sample size, achieved power, or minimum detectable effect.

Core Features & Use Cases

It supports common frequentist planning workflows for t-tests, ANOVA, chi-squared tests, correlation, and regression, including grant writing, pre-registration, pilot-informed planning, and design comparisons such as paired versus independent samples. It also guards against misuse by refusing post-hoc or observed power, requiring an explicit effect-size provenance, and prompting sensitivity checks so fragile assumptions are visible before the study runs.

Quick Start

Use the running-power-analysis skill to estimate the required sample size for a planned two-arm study with 80% power, alpha 0.05, and a clinically meaningful effect based on prior evidence.

Frequently Asked Questions about running-power-analysis

High-intent search queries and answers about installing and using this skill.

FAQPage Schema
How do I calculate sample size for a t-test before data collection?▼

Calculate sample size for a t-test by providing the test family, alpha, power, and an effect size with explicit provenance. The skill uses these inputs to estimate the required n for your planned study design.

What is statistical power analysis and when do I need it for pre-registration?▼

Statistical power analysis is a prospective planning technique that turns an expected effect and target alpha into defensible sample sizes. You need it for pre-registration and grant writing to justify your study design before data collection begins.

Can I compute observed power after my study is complete?▼

No, computing observed power is explicitly refused. The skill focuses strictly on prospective planning, requiring you to define alpha, power, and effect-size scale before data collection rather than calculating post-hoc power.

How do I determine the minimum detectable effect for an ANOVA design?▼

Determine the minimum detectable effect for an ANOVA by specifying your sample size, alpha, and power. The calculation requires you to choose the test family and state your effect-size provenance to output the MDE.

What is the best way to plan sample size using pilot data?▼

The best way to plan sample size using pilot data is to derive your effect-size provenance from the pilot results, then run a sensitivity analysis. This ensures fragile assumptions are visible before the main study runs.

Why does my power analysis require a sensitivity analysis?▼

Power analysis requires a sensitivity analysis to make fragile effect-size assumptions visible before data collection. Prompting these checks ensures your sample size estimates remain defensible across varying conditions.