SIX SIGMA Glossary: Kruskal Wallis Test

The Kruskal-Wallis test is a distribution free (nonparametric) alternative to ANOVA. It compares several samples and tests the hypothesis:

H₀ the samples are all drawn from populations that have equal means
H₁ the mean of at least one of the populations is different

The test involves:

sort the combined results into size order and allocate ranks
form a table that contains the ranks, instead of the values
calculate the test statistic 'K using the formula:

kruskal wallace equation

Where:

R_i	sum of the ranks in row 'i'
J	number of values in row 'i'
I	number of rows
N	total number of values

'K' has an approximately χ ² distribution with degrees of freedom I - 1

MiC Quality offers online courses that can help you prepare for the American Society for Quality (ASQ) Certified Six Sigma Black Belt examination.

Try out our courses by taking the first module of the Primer in Statistics free of charge.

[SIX SIGMA GLOSSARY ALPHABETICAL INDEX] [SIX SIGMA GLOSSARY INDEX OF TOPICS]

[Top]

MiC Quality Courses

::	Six Sigma Primer
::	Primer in Statistics
::	Advanced Statistics
::	Statistical Process Control SPC
::	Advanced SPC
::	Design of Experiments
::	Advanced DOE
::	Measurement Systems Analysis MSA/ Gage R&R

	Primer in Statistics FREE First Module "Introduction to Statistics"
	Primer in Statistics FREE Reference Booklet
	FREE Excel Primer