<oops, this got sent as reply to Andrew only>
Andrew Robinson wrote:
In your data, subject is nested within sequence. Was that your
intention?
Presumably yes. This looks like a standard cross-over design.
I fail to see what the interaction between subject and sequence might
mean, so I also have no idea what SPSS might have done. (The list does
not allow .doc attachments).
Since this is a balanced design, you can get almost the right analysis by
m <- lm(Max ~ sequence + subject + period +
+ drug, data=Data)
anova(m)
Analysis of Variance Table
Response: Max
Df Sum Sq Mean Sq F value Pr(>F)
sequence 1 585 585 0.0160 0.9014
subject 12 634325 52860 1.4469 0.2660
period 1 63175 63175 1.7293 0.2131
drug 1 58149 58149 1.5917 0.2311
Residuals 12 438395 36533
in which you have to know that sequence is aliased with the drug:period
interaction, AND that it needs to be compared with the intersubject
variation. I.e. the F test is wrong and should be replaced with F=
585/52860 = 0.011on 1 and 12 df.
However, a better way is
summary(aov(Max ~ period*drug + Error(subject), data=Data))
Error: subject
Df Sum Sq Mean Sq F value Pr(>F)
period:drug 1 585 585 0.0111 0.918
Residuals 12 634325 52860
Error: Within
Df Sum Sq Mean Sq F value Pr(>F)
period 1 63175 63175 1.7293 0.2131
drug 1 58149 58149 1.5917 0.2311
Residuals 12 438395 36533
--
O__ ---- Peter Dalgaard Øster Farimagsgade 5, Entr.B
c/ /'_ --- Dept. of Biostatistics PO Box 2099, 1014 Cph. K
(*) \(*) -- University of Copenhagen Denmark Ph: (+45) 35327918
~~~~~~~~~~ - ([EMAIL PROTECTED]) FAX: (+45) 35327907
______________________________________________
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.
