There are three treatment groups: control mice, diseased mice (EAE) with optic neuritis, and treated diseased mice (EAE + treatment).

We have explained the goals of this study in another tutorial on the display of data, 1 and they are summarized here. For brevity, we refer to the measured response as retinal thickness. Non-parametric tests are used for inference when the sample data are not normally distributed or the sample is too small to assess its true distribution and will be covered in a separate tutorial.įor this tutorial on parametric statistical inference, optical coherence tomography thickness measurements of the inner retinal layers recorded in eyes of control mice and mice with optic neuritis produced by experimental autoimmune encephalitis (EAE) serve as illustration. Parametric tests refer to those that make assumptions about the distribution of the data, most commonly assuming that observations follow normal (Gaussian) distributions or that observations can be mathematically transformed to a normal distribution (e.g., log transformation).

This tutorial deals with statistical parametric tests for inference, such as comparing the means of two or more groups.

Graphpad prism tutorial multiple groups