Repeated measure analysis on Likert scale

[lizzy28]

Hi all,

Is it possible to conduct repeated measure analysis on Likert scale measures?

Thank you!

Lizi

[SteveDenham]

The problem here is that there is no consensus method.  There are papers out there that point out that linear modeling techniques are very robust to the assumption of normality.  There are other papers out there that insist that since Likert scales are ordinal, rather than rational, you should not use any methods that assume normality of the residuals.  So what to do?

If you are good at interpreting multinomial data and the various odds ratios involved, then you might consider using PROC GLIMMIX with a multinomial distribution and a G side structure that handles the repeated nature of the data.

If you are willing to trust in the robustness to assumptions, and you can make a case that either a) the gap between the scores is linear or b) you can weight each score by some utility factor, then a repeated measures analysis of variance will work.

SteveDenham.

[StatDave]

See the example titled "Alternating Logistic Regression for Ordinal Multinomial Data" in the documentation of PROC GEE which models a repeated ordinal response using both an alternating logistic regression (ALR) model and an ordinal Generalized Estimating Equations (GEE) model in that procedure.

[SteveDenham]

@lizzy28 , the response by @StatDave  is spot-on for what you want to do.

SteveDenham