Table: Report oneway KruskalWallis...


Performs a oneway KruskalWallis analysis on the data in one column of a selected Table and reports the results in the info window. This test is sometimes refered to as a oneway analysis of variance for nonnormally distributed data.
Settings

Column with data

the label of the column who's data will be analyzed.

Factor

the label of the column with the names of the levels.
Algorithm
The analysis is done on the ranked data and consists of the following steps:

1. Rank all the N data points together, i.e. rank the data from 1 to N.

2. The test statistic is:
K = (12 / (N(N+1)) Σ_{i=1}^{g} n_{i} (meanRank_{i})^{2}  3(N+1), 

where g is the number of levels, n_{i} the number of data in ith level and meanRank_{i} the average rank of the ith level.

3. The p value is approximated by the χ^{2} (K, g  1) distribution.
© djmw, June 17, 2012