FREE INTERACTIVE TOOLS
Statistical Tools
Three free interactive tools to support every stage of your research — from choosing the right test to calculating your sample size and reporting effect sizes.
Designed for students, researchers, and educators in psychology, education, health and social sciences.
Free Interactive Tools
STATS SELECTION TOOL
Which statistical test should I use?
Answer a few questions about your research question, variables, and data — get an instant recommendation for the most appropriate statistical test.
SAMPLE SIZE CALCULATOR
How many participants
do I need?
Calculate the sample size required for your planned analysis — with power analysis built in and an APA-style reporting paragraph ready to use.
EFFECT SIZE CALCULATOR
What is my effect size?
Convert between effect size measures, extract an effect size from reported statistics, or calculate one from your group data. Useful for planning and reporting.
FIRST TIME HERE?
How the tools work together
Most research projects use the tools in this order — but you can use any tool independently at any time.
1
STATS SELECTION TOOL
Choose your test
Start here if you are unsure which statistical test suits your research question and data. The tool guides you through plain-English questions and recommends the most appropriate approach for your situation.
2
SAMPLE SIZE CALCULATOR
Plan your sample
Once you know which test you plan to use, calculate how many participants your study needs. You will need an estimate of effect size — use the Effect Size Calculator if you need help with this step.
3
EFFECT SIZE CALCULATOR
Work with effect sizes
Use this tool when you need to find, convert, or report an effect size — whether you are planning a study, reviewing published research, or writing up your results.
New to statistics?
Before using the Stats Selection Tool it helps to understand a few key concepts about your data — what type of variables you have, what you are trying to find out, and some basic checks to run before choosing a test. The Before You Start page covers all of this clearly and concisely.