Friday, 1 November 2013

One-way ANOVA Test Calculator with Post-Hoc Analysis

Please click to add a dataset group - need at least three

The one-way ANOVA test is a widely used parametric test that is used to determine whether three or more groups have the same means. This test relies on the assumption that all the groups have Normal distribution, and that the variances for all the groups are similar. The Null Hypothesis for this test is that all groups have the same (or quite similar) means. This blog post implements an ANOVA test calculator. Should the Null Hypothesis be rejected, a post-hoc analysis will be carried out to determine which groups' means are significantly different.

Simply click on the link near the top to add text boxes. Each text box stores a single group/dataset and needs to be filled in with comma separated numbers. Alternatively, you can choose two file entry methods:-

  1. Select multiple single column CSV files to populate the text boxes by repeatedly pressing the Choose File button - there must be one distinct (and differently named) file for each text box i.e. one file per group. Each file can have a different number of samples.
  2. Select a single multi-column CSV file by pressing the Choose File button once, where the number of columns equals the number of groups - all groups need to have the same number of samples.

There is a graph at the bottom which will display scatter plots for all the groups and the grand mean, once the calculate button is pressed.

Results pending...

Scatter plot of all the groups, and grand mean
Sample values
Group number