Dear Statalisters,
I have the following dataset (except I have it in long format-one measurement per row) :
WireType WireNo Trial Force
A A1 1,2,3,4,5 5 measurements-1 per trial
A A2 1,2,3,4,5 5 measurements-1 per trial
A A3 1,2,3,4,5 5 measurements-1 per trial
A A4 1,2,3,4,5 5 measurements-1 per trial
A A5 1,2,3,4,5 5 measurements-1 per trial
B B1 1,2,3,4,5 5 measurements-1 per trial
B B2 1,2,3,4,5 5 measurements-1 per trial
B B3 1,2,3,4,5 5 measurements-1 per trial
B B4 1,2,3,4,5 5 measurements-1 per trial
B B5 1,2,3,4,5 5 measurements-1 per trial
C C1 1,2,3,4,5 5 measurements-1 per trial
C C2 1,2,3,4,5 5 measurements-1 per trial
C C3 1,2,3,4,5 5 measurements-1 per trial
C C4 1,2,3,4,5 5 measurements-1 per trial
C C5 1,2,3,4,5 5 measurements-1 per trial
D D1 1,2,3,4,5 5 measurements-1 per trial
D D2 1,2,3,4,5 5 measurements-1 per trial
D D3 1,2,3,4,5 5 measurements-1 per trial
D D4 1,2,3,4,5 5 measurements-1 per trial
D D5 1,2,3,4,5 5 measurements-1 per trial
I am testing the forces generated by 4 different wiretypes to see if there are significant differences.
For each wiretype (categorical A B C D) I am using 5 specimens (A1-5,..D1-5) and for each specimen I am repeating the measurement 5 times.
The outcome is force and it is a continuous variable.
This looks like a repeated measures with each trial nested in the WireNo and the WireNo nested inside WireType?
I was trying to use the xtgee command but I was not sure how to construct it:
xi:xtreg force i.xxxxx i.yyyyyy, i(zzzzz) ?
Any help would be appreciated.
Thank you very much,
Nikolaos
*
* For searches and help try:
* http://www.stata.com/help.cgi?search
* http://www.stata.com/support/statalist/faq
* http://www.ats.ucla.edu/stat/stata/
