This paper explains how to select the correct statistical test for a research project, clinical trial, or other investigation. It is important that the appropriate statistical analysis is decided upon before starting the study, at the stage of planning itself, to get correct analysis of data. This cannot be decided arbitrarily after the study is over and data has already been collected. Many studies have been rejected due to faulty selection of statistical test. The test to be used depends upon the type of research question being asked. The other determining factors are the type of data being analyzed and the number of groups or data sets involved in the study.