Analyzing evaluation data: Modelling and testing for homogeneity

In the evaluation process of a given service, different issues are worth of analysis. In first instance, it is interesting to assess how the evaluation responses changes over the time and whether there is an effect of the raters' features. Secondly, when the service is made up by different items, it is important to verify if the satisfaction feelings of the users/consumers are the same with respect to all the dimensions. At this scope, the paper proposes a modelling approach for analyzing and testing ordinal/rating data. Some evidence from University services evaluation shows the usefulness of this procedure in a real case-study.