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.