[R] Question about Tukey HSD (stat package)

[JRG]

On 14 Mar 2005 at 16:13, Peter Dalgaard wrote:

> Alice Le Bars <alice.le-bars at nantes.inserm.fr> writes:
> 
> > Dear all,
> > 
> > I would be glad if someone could tell me if Tukey HSD (function of
> > stats library) accept the NA values and could correct the unbalanced
> > design (different number of sample in each group)
> 
> I don't think the *theory* of the HSD allows this. There is some more
> or less well-founded speculation that if the imbalance is not too bad,
> then the HSD results are somewhat useful anyway, but please consider
> using the multcomp package, which is specifically designed to get
> these things right.
> 

I believe that Hayter (JASA, 1984, 12, 61--75) proves that the so-called Tukey-Kramer method is guarnateed to be conservative for 
any set of cell sizes --- under the usual ANOVA model, of course.

---JRG




> -- 
>    O__  ---- Peter Dalgaard             Blegdamsvej 3  
>   c/ /'_ --- Dept. of Biostatistics     2200 Cph. N   
>  (*) \(*) -- University of Copenhagen   Denmark      Ph: (+45) 35327918
> ~~~~~~~~~~ - (p.dalgaard at biostat.ku.dk)             FAX: (+45) 35327907
> 
> ______________________________________________
> R-help at stat.math.ethz.ch mailing list
> https://stat.ethz.ch/mailman/listinfo/r-help
> PLEASE do read the posting guide! http://www.R-project.org/posting-guide.html


John R. Gleason

Syracuse University
430 Huntington Hall                      Voice:   315-443-3107
Syracuse, NY 13244-2340  USA             FAX:     315-443-4085

PGP public key at keyservers