Use z-scores in Repeated Measures ANCOVA?

Hi everyone,
My dissertation has participants answer three questions at four different timepoints in a video. For each timepoint, I have averaged the three questions for an average response per timepoint (4 scores). I also have a dichotomous between subjects variable, and two continuous covariates. My question is, do I need to standardize (z-scores) all the continuous variables within the analysis? Or can I just use the raw scores for each variable?

Thanks for your help.


TS Contributor
Hi rkprice,

Standardization depends on your particular data and objectives. There's no need to do it unless you have a specific reason within your data/research.I'd say the decision is based mostly on what you can interpret easier.