How we change what others think, feel, believe and do
Choosing parametric test
Use the table below to choose the test. See below for further details.
The test statistic in all tests is calculated as:
systematic variation / random variation
= (measured difference between sample means) / (mean difference expected by chance)
= (variability between treatments) / (variability within treatments)
The common principles of measurement are:
Single sample designs take data from a single sample to test a hypothesis about a single population.
Independent-measures designs take separate samples from each population or treatment.
Related-samples designs, including repeated-measures and matched-subjects designs.
Repeated measures designs have only one sample, with each subject being measured in all treatment conditions.
In matched-subject designs, each person in one sample is matched with a subject in each of the other samples.