Plan My Analysis
Answer a few plain-English questions about your study and get a complete, printable analysis plan — the recommended test and why, the assumptions to check, the sample size you'll need (from the same exact power math as the calculator), and a ready-to-fill APA write-up skeleton. Hand it to your supervisor.
A plan, not a promise. This wizard picks a sensible default analysis and a sample size for the effect you specify — but real studies have wrinkles no flowchart sees. Confirm the assumptions, and decide your analysis before you collect data — ideally by preregistering it, so you can't switch tests until something turns up p < .05.
Sample sizes assume 80% power at α = .05 (the field's convention), and are computed with the exact noncentral t, F and χ² distributions — the same engine as the power calculator, where you can vary the power, α and tails.
How to use your plan
- Work through the questions until you reach a recommended test.
- Set the effect size you expect — pick a benchmark, borrow one from prior literature, or read the "no idea?" note. The sample size updates live.
- Print it (the button on the plan) — only the plan card prints, with a header and this page's URL, so it's a tidy one-pager for a supervisor or ethics application.
- Follow the links to the interactive lesson, the SPSS/JASP walkthrough, the APA formatter (pre-set to your test), and the power curve.
Prefer the quick version?
If you just want the test name, the Which Test Should I Use? chooser is the express lane. This page is its grown-up sibling — it keeps going, all the way to a sample size and a write-up. For the picture side of a thesis, see Which Chart Should I Use?