StatReasonANOVA & Group Comparisons
A two-sample t-test compares two groups. These tools compare three or more groups at once, without inflating your false-positive rate by running many pairwise t-tests instead. Every engine here reports cell sizes, group means and standard deviations, the omnibus test statistic, degrees of freedom, p-value, and an effect size together.
These tools calculate group sample sizes, the observed variance ratio, and residuals directly from your data, but a significant omnibus test does not by itself identify which specific groups differ, and whether your design is genuinely independent or repeated measures is left for you to specify correctly.
Engines in this category
- One-Way ANOVA Calculator
Compare means across three or more independent groups at once.
- Welch ANOVA Calculator
Compare group means without assuming equal variance across groups.
- Eta Squared Calculator
Quantify the proportion of variation explained by group membership.
- Omega Squared Calculator
Provide a less biased ANOVA effect-size estimate than eta squared.
- Bonferroni Multiple Comparisons Calculator
Adjust a declared family of p-values or alpha for multiple comparisons.
- Repeated Measures ANOVA Calculator
Compare three or more related measurements on the same subjects.
- Two-Way ANOVA Calculator
Estimate two factor effects and their interaction in a balanced design.
- ANCOVA Calculator
Compare adjusted group means after controlling for a covariate.
- Tukey HSD Calculator
Make family-wise adjusted all-pair comparisons after a one-way ANOVA.
- Games-Howell Test
Make pairwise comparisons after group variances are found unequal.