Seminar: "Bi-factor and second-order copula models for item response data"
AUEB STATISTICS SEMINAR SERIES SEPTEMBER 2021
Aristidis Nikoloulopoulos, Associate Professor in Statistics, School of Computing Sciences, University of East Anglia, UK.
Bi-factor and second-order copula models for item response data
Bi-factor and second-order models based on copulas are proposed for item response data, where the items can be split into non-overlapping groups such that there is a homogeneous dependence within each group. Our general models include the Gaussian bi-factor and second-order models as special cases and can lead to more probability in the joint upper or lower tail compared with the Gaussian bi-factor and second-order models. Details on maximum likelihood estimation of parameters for the bi-factor and second-order copula models are given, as well as model selection and goodness-of-fit techniques. Our general methodology is demonstrated with an extensive simulation study and illustrated for the Toronto Alexithymia Scale.