Reading a research article part II: parametric and nonparametric statistics.

Researchers often try to use a randomization technique in an attempt to reduce bias and ensure that treatment and control groups are as similar as possible. This article has provided an overview of how researchers might use parametric and nonparametric statistics when analyzing data and looking for differences between groups. Researchers must consider the types of data and choose the tests that are appropriate for the variable types to draw appropriate conclusions. The next article in this series will address comparison of more than two groups and repeated measures and other design issues.