RESEARCH · METHODS · EVIDENCE
Compare means with t-tests
Browse statistics lessons
- Statistics for research
- Center and spread
- Distributions and standard errors
- Statistical inference
- P-values and interpretation
- Critical values and test direction
- Compare means with t-tests
- Read t-test output
- Compare several means with ANOVA
- Read an ANOVA table
- Analyze categorical counts
- Read chi-square output
- Describe an association
- Read correlation results
- Interpret a regression model
- Choose a statistical method
- Statistics resources
Use an independent-samples method for separate groups and a paired method for matched observations or repeated measurements. Welch’s two-sample t-test does not require equal group variances. Independence, influential observations, and the distribution relevant to the test still matter.
Report group sample sizes, the estimated mean difference, confidence interval, test statistic, degrees of freedom, and p-value. Choosing a test requires understanding how the observations were collected.
References: NIST two-sample t-test