Le mercredi 03 février 2010 à 00:01 -0500, David Winsemius a écrit : > On Feb 2, 2010, at 11:38 PM, Peng Yu wrote: > > > ?contrast in the contrast package gives me the following description. > > However, I have no idea what Type II and III contrasts are. Could > > somebody explain it to me? And what does 'type' mean here? > > > > *‘type’*: set ‘type="average"’ to average the individual contrasts > > (e.g., to obtain a Type II or III contrast) > > In no particular order: > http://courses.washington.edu/b570/handouts/type3ss.pdf > http://core.ecu.edu/psyc/wuenschk/SAS/SS1234.doc > http://n4.nabble.com/a-kinder-view-of-Type-III-SS-td847282.html > > Don't expect any follow-up questions to be answered or further > citations offered. This is really more in the realm of statistics > education than an R specific question.
Nonwhistanding David Winsemius' closing remark, I'd like to add something that should be requested reading (and maybe hinted at in lm()'s help page) : http://www.stats.ox.ac.uk/pub/MASS3/Exegeses.pdf (BTW, despite is age, MASS *is* requested reading, and Bill Venables' exegeses should be part of it). HTH, -- Emmanuel Charpentier, DDS, MsC :-) ______________________________________________ R-help@r-project.org mailing list https://stat.ethz.ch/mailman/listinfo/r-help PLEASE do read the posting guide http://www.R-project.org/posting-guide.html and provide commented, minimal, self-contained, reproducible code.
