tsunhin wong wrote:
Dear R users,

I have copied for following table from an article on "Using confidence
intervals in within-subject designs":

Subject 1sec 2sec 5sec
1 10 13 13 12.00
2 6 8 8 7.33
3 11 14 14 13.00
4 22 23 25 23.33
5 16 18 20 18.00
6 15 17 17 16.33
7 1 1 4 2.00
8 12 15 17 14.67
9 9 12 12 11.00
10 8 9 12 9.67

I rearranged the data this way:
subject<-factor(c(1,2,3,4,5,6,7,8,9,10,1,2,3,4,5,6,7,8,9,10,1,2,3,4,5,6,7,8,9,10))
condition<-factor(c(1,1,1,1,1,1,1,1,1,1,2,2,2,2,2,2,2,2,2,2,5,5,5,5,5,5,5,5,5,5))
recall<-factor(c(10,6,11,22,16,15,1,12,9,8,13,8,14,23,18,17,1,15,12,9,13,8,14,25,20,17,4,17,12,12))
example<-cbind(subject,condition,recall)

Using ANOVA (aov), I should have DF for condition = 2, DF of subjects
= 9, Interaction DF = 18
And a term for mean square of interaction. (0.61)

Your data are not factors when you get to use them, hence the 1DF. It is the cbind() that is doing you in. Try

example <- data.frame(subject,condition,recall)

However, "recall" should _not_ be a factor.

-p

But, I have something like below instead:
aov.recall <- aov(recall~condition + 
Error(subject/condition),data=as.data.frame(example))
summary(aov.recall)

Error: subject
          Df Sum Sq Mean Sq F value Pr(>F)
Residuals  1 12.898  12.898

Error: subject:condition
          Df Sum Sq Mean Sq
condition  1 34.505  34.505

Error: Within
          Df Sum Sq Mean Sq F value Pr(>F)
condition  1   3.22    3.22  0.1378 0.7135
Residuals 26 607.54   23.37

The within-subject (repeated measure) anova of R seems to be a bit
subtle for me, please point out the errors that I have made if you
can.
Thank you very much!

- John

______________________________________________
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.


--
   O__  ---- Peter Dalgaard             Ă˜ster Farimagsgade 5, Entr.B
  c/ /'_ --- Dept. of Biostatistics     PO Box 2099, 1014 Cph. K
 (*) \(*) -- University of Copenhagen   Denmark      Ph:  (+45) 35327918
~~~~~~~~~~ - (p.dalga...@biostat.ku.dk)              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.

Reply via email to