Testing Whether Group Differences Matter

Statistical analysis helps determine whether differences between an experimental group and a control group are meaningful. After data are collected, researchers check whether the results are likely to be real or just due to chance. If a difference is caused by chance, it is not considered meaningful.

After researchers collect empirical data from a predetermined sample size, they can follow up with statistical analyses to determine whether the differences they observed between groups or variables are meaningful or the result of chance alone.

For example, perhaps a researcher finds that undergraduate students who were as...