Statistics for Researchers,
Not Statisticians
Clear, jargon-free guides to help you choose, run, interpret, and report statistical tests for your thesis, dissertation, or research project.
What do you need help with?
Choose a Test
Answer a few questions about your data and get a test recommendation.
Learn a Concept
Plain-language tutorials on effect size, power analysis, t-tests, ANOVA, and more.
Calculate
Free calculators for effect size, power analysis, sample size, and reliability.
Report Results
APA-formatted templates and examples for reporting your statistical results.
Read the Blog
Practical guides on common statistical challenges in research.
Download Cheat Sheets
Free PDF reference cards for statistical tests, APA reporting, and more.
Popular Concepts
View all →Chi-Square Test of Independence
Learn how to perform a chi-square test of independence to analyze associations between categorical variables, with formulas, examples, and Cramer's V.
beginnerCronbach's Alpha
Understand Cronbach's alpha for measuring internal consistency reliability. Learn the formula, interpretation guidelines, and what to do when alpha is low.
beginnerDescriptive Statistics
Master descriptive statistics: learn about mean, median, mode, standard deviation, variance, and range. Know when to use each measure for your research data.
beginnerEffect Size
Learn what effect size is, why it matters more than p-values alone, and how to calculate and interpret Cohen's d, Hedges' g, and eta-squared for your research.
beginnerIndependent Samples t-Test
Learn how to conduct and interpret an independent samples t-test, including assumptions, formulas, worked examples, and APA reporting guidelines.
beginnerInter-Rater Reliability
Learn how to assess inter-rater reliability using Cohen's Kappa and ICC. Understand percent agreement, chance correction, and interpretation benchmarks.
intermediateLatest from the Blog
View all →How to Choose the Right Statistical Test: A Beginner's Guide
A step-by-step guide to selecting the right statistical test for your research question, data type, and study design. Covers t-tests, ANOVA, chi-square, correlation, and regression.
Free Statistics Tools Every Graduate Student Should Bookmark
Discover the best free statistics tools for dissertation research. Includes calculators, software, and resources for power analysis, effect sizes, and more.
The Assumption of Normality: How to Test It and What to Do If It Fails
Learn how to test the normality assumption using Shapiro-Wilk, Q-Q plots, and skewness. Includes practical solutions when your data isn't normally distributed.
Ready to run your analysis?
Use the free calculator tools on Subthesis to compute effect sizes, power analysis, sample sizes, and more.