Compare the means of two separate groups. Enter raw scores or summary statistics and get the test statistic, exact p value, Cohen's d, confidence interval, and an APA 7 formatted result.
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Get QuantaUse this test when you measured one continuous outcome (like test scores, reaction time, or a survey scale) in two different groups of people and want to know whether the group means differ. Typical examples: treatment vs control, first-generation vs continuing-generation students, two teaching methods.
If the same people were measured twice (pre and post), use the paired samples t test instead. If you have more than two groups, you need a one-way ANOVA, which you can run in Quanta.
Student's version assumes both groups have equal population variances. Welch's version does not, at almost no cost in power, which is why methodologists recommend Welch as the default. If your group SDs are similar and group sizes are equal, the two give nearly identical answers.
An APA 7 report includes the group means and standard deviations, the t statistic with degrees of freedom, the exact p value (no leading zero), the effect size, and the confidence interval for the mean difference. The calculator assembles this sentence for you; copy it and adapt the variable names to your study.