Faculty of Behavioural and Social Sciences
University of Groningen
Dimensionality assessmentof polytomous items
Personality scales are popular instruments to measure individual’s traits. As important decisions on individuals are based on such measurements, scales of good quality are essential. Scale evaluation critically depends on appropriately assessing the number of traits measured, that is, the dimensionality of the items. For personality scales, which commonly consist of polytomous items, it is unclear which dimensionality assessment method should be used. A comparative study, including various methods associated with factor analysis and nonparametric item response theory, will be performed. The ultimate goal is to provide proper, well-founded guidelines for the dimensionality assessment of polytomous items in personality scales.
NWO (Netherlands Organisation for Scientific Research)
– dr M.E. Timmerman (University of Groningen)
– dr R.R. Meijer (University of Groningen)
1 September 2010 – 1 September 2014