SIX SIGMA GLOSSARY PROCESS IMPROVEMENT AND SIX SIGMA
 ONLINE COURSES FREE TRIAL SIX SIGMA FAQ BROCHURES LICENSES ENROLL
 GLOSSARY
 :: Online Courses :: Free Trial :: Six Sigma >> Glossary >> Calculators >> Reference Tables >> Book Reviews >> Black Belt ASQ :: FAQ :: Brochures :: Licenses :: Discounts
 Welcome to MiC Quality Six Sigma Resources Glen Netherwood MiC Quality Online Learning
 :: Home ::Six Sigma ::SIX SIGMA GLOSSARY: Friedman's Test :: CURRENT STUDENTS LOGIN

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

Friedman's Test

Friedman's Test is a nonparametric alternative to two-way analysis of variance. The hypothesis is:

H0 the means of all the samples are equal
H1 the mean of at least one of the samples is different

Consider the example where three treatments are evaluated on four different patients:

 Therapy Andrew Belinda Chris Dave Relaxed 110 140 100 130 Normal 115 150 105 135 High Intensity 117 155 100 135

The test involves:

• impose ranks on each of the columns. If values are equal, average the ranks they would have got if they were slightly different:
 Therapy Andrew Belinda Chris Dave Relaxed 1 1 1.5 1 Normal 2 2 3 2.5 High Intensity 3 3 1.5 2.5
• calculate the Fr statistic using the formula:

Where:

 I Number of samples (treatments) J Number of blocks Ri sum of the ranks in row 'i'

This gives a value for Fr of 4.65

The value of Fr has an approximately chi-square distribution with I - 1 degrees of freedom.

 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