R help - Dec 2004 - Friedman test for replicated blocked data

Hi,

I would need to extend the Friedman test to a replicated
design. Currently the function: friedman.test(y, ...) only works for
unreplicated designs.

I found in Conover 1999 "Practical Nonparamteric statistics" an
extension of the formula to my case.

Nevertheless, other sources, like Sheskin 2000 "Parametric and
Nonparametric statistical Procedures" and Daniel 1990 "Applied
nonparametric statistics" give a different formula from that of Conover
in the unreplicated case. Since they do not provide the extension of
this formula to the replicated case I would like to know if someone
could give me a reference where I could find such extension. The formula
is indeed very simple:

F= z \sqrt{bk(k+1)/6}

where z is a quantile from the normal distribution, b the number of
blocks and k the number of treatments.

Unfortunately, the sources cited do not provide indications from where
the formula comes from.


Thank you for consideration,


Greetings,


Marco


----------------------------------
Marco Chiarandini,
Technische Universitaet Darmstadt

Hi Marco
> I would need to extend the Friedman test to a replicated
> design. Currently the function: friedman.test(y, ...) only works for
> unreplicated designs.
You'll find something about this topic in:
 
Myles Hollander & Douglas A. Wolfe (1999), _Nonparametric
statistical methods_. 2nd edition, John Wiley & Sons. Chapter 7 

In Chapter 7.9 there is an extension to the balanced replicated
design. Notice also the comments 70 and 74 about the
motivation of the test and the approximation of the test
statistic and comment 77 for an extension to the general case
(unbalanced). 
They give further references for more details, too. 

Hope this will help you

Christoph

-- 
Christoph Buser <buser at stat.math.ethz.ch>
Seminar fuer Statistik, LEO C11
ETH (Federal Inst. Technology)	8092 Zurich	 SWITZERLAND
phone: x-41-1-632-5414		fax: 632-1228
http://stat.ethz.ch/~buser/