R help - Jun 2012 - Kruskal Wallis Post hoc

Hi, I have searched and found a response to a question similar to mine but
when I tried the code, R says it's not an actual function so I thought
I'd
ask here.

http://r.789695.n4.nabble.com/file/n4633035/Cookies.csv Cookies.csv 

I have attached the data I am using.  I am trying to look at two things: how
moisture content changes over time, and how it changes along the length of a
log (bolt).  My data is not normal and doesn't become normal after ArcSin or
Log transformations.  Because the 'Days' has 4 levels, I performed a
Kruskal-Wallis (kruskal.test) and got significant results.  Same for
comparing 'Cookie'. 

Neither of these have only 2 levels so significance here doesn't really
explain it in depth....but everything I'm finding for post hoc with a KW
says Mann Whitney.  But when I try this (wilcox.test) in R it doesn't work -
bc it should only have 2 levels.

Can I simply run a tukeyHSD to see differences between levels?

--
View this message in context:
http://r.789695.n4.nabble.com/Kruskal-Wallis-Post-hoc-tp4633035.html
Sent from the R help mailing list archive at Nabble.com.

Look at kruskalmc in package pgirmess and package multcomView for plotting
the results.

----------------------------------------------
David L Carlson
Associate Professor of Anthropology
Texas A&M University
College Station, TX 77843-4352


> -----Original Message-----
> From: r-help-bounces at r-project.org [mailto:r-help-bounces at r-
> project.org] On Behalf Of jhartsho
> Sent: Monday, June 11, 2012 2:27 PM
> To: r-help at r-project.org
> Subject: [R] Kruskal Wallis Post hoc
> 
> Hi, I have searched and found a response to a question similar to mine
> but
> when I tried the code, R says it's not an actual function so I thought
> I'd
> ask here.
> 
> http://r.789695.n4.nabble.com/file/n4633035/Cookies.csv Cookies.csv
> 
> I have attached the data I am using.  I am trying to look at two
> things: how
> moisture content changes over time, and how it changes along the length
> of a
> log (bolt).  My data is not normal and doesn't become normal after
> ArcSin or
> Log transformations.  Because the 'Days' has 4 levels, I performed
a
> Kruskal-Wallis (kruskal.test) and got significant results.  Same for
> comparing 'Cookie'.
> 
> Neither of these have only 2 levels so significance here doesn't really
> explain it in depth....but everything I'm finding for post hoc with a
> KW
> says Mann Whitney.  But when I try this (wilcox.test) in R it doesn't
> work -
> bc it should only have 2 levels.
> 
> Can I simply run a tukeyHSD to see differences between levels?
> 
> --
> View this message in context: http://r.789695.n4.nabble.com/Kruskal-
> Wallis-Post-hoc-tp4633035.html
> Sent from the R help mailing list archive at Nabble.com.
> 
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