[BioC] different results because of an upgrade

[Ingrid H.G. Østensen]

Hi

I did an analysis for some scientist in April using limma and knn.impute.
I did the same analysis on the same data set and the same commands
yesterday but I got a different result. More genes were classified as
differential expressed and some of the genes that were differential
expressed earlier are not any more.

I think that the reason for this might be that R and the Bioconductor
packages has been updated since the last time I run these commands on this
data set. If this is the reason for the different results are the most
trustworthy, and how do I explain this to the scientist without them
loosing their faith in R/Bioconductor?

If the changes in R and Bioconductor can not cause these changes in the
results, what might be the reason?

Regards,
Ingrid



-- 
Ingrid H.G. Østensen
Bioinformatics user support (NMC)
Department of Tumour Biology
The Norwegian Radiumhospital
0310 Oslo

E -mail: ingrid at microarray.no
Phone:  +47 22 93 54 11
Fax:  +47 22 52 24 21