topic Re: Transforming data for use in repeated measures ANOVA in SAS Studio

Transforming data for use in repeated measures ANOVA

xshinbrot0 — Wed, 24 Jan 2018 00:52:38 GMT

Hi there,

I am interested in figuring out how to transform my data set so I can use a repeated measures ANOVA.

Right now I have an excel spreadsheet uploaded into SAS studio. It is now organized as this example, where there is a subject, a group trial, and time (pre, post- 1 week, post 1 month and control), with the dependent variable being the amount of learning. Now to use repeated measures I want to make sure that there is the assumption that time 1,2,3 are correlated (since its the same person). I read here that I will need to transform it so that all the dependent variables are on the same line (e.g. subject 1 would have 15, 19, 25 on one line). I don't understand how to do that in SAS. I can't just make up "ave_learn1" "ave_learn2" "ave_learn3" can I? How do I do this? Please advise.

 data Old;
      input Subject Group Time ave_learn;
   datalines;
    1 1 1 15
    1 1 2 19
    1 1 3 25
    2 1 1 21
    2 1 2 18
    2 1 3 17
    1 2 1 14
    1 2 2 12
    1 2 3 16
    2 2 1 11
    2 2 2 20

Re: Transforming data for use in repeated measures ANOVA

ballardw — Wed, 24 Jan 2018 01:01:29 GMT

Is subject 1 in group 1 and in group 2 supposed to be the same individual?

proc sort data=old;
by subject group;
run;

proc transpose data =old out=new prefix=t;
   by subject group;
   id time;
   var ave_learn;
run;

Re: Transforming data for use in repeated measures ANOVA

xshinbrot0 — Wed, 24 Jan 2018 03:13:46 GMT

The way that I have it yes, it has the subject id with three lines of code (subject=1, pre-survey time=1; subject=1 postsurvey time=2; subject=1 postsurvey time=3), Let me try that code though, thank you!