[Forum SIS] Seminario

[Francesca De Battisti (francesca.debattisti)]

Martedì 11 febbraio 2014 
 
Silvia Bacci (Department of Economics, Finance, and Statistics - University of Perugia) terrà il seminario dal titolo:
 
 
 
“Multidimensional latent class item response models for binary and ordinal
polytomous items: theory and application with R software”
 
 
 
presso la Facoltà di Scienze Politiche, Economiche e Sociali dell’Università degli Studi di Milano (aula seminari DEMM, II piano, via Conservatorio 7). 
 
 
 
Il seminario è programmato dalle 14.00 alle 15.15 circa. 
 
 
 
Abstract
 
A class of Item Response Theory (IRT) models for binary and ordinal polytomous items is illustrated and an R package for dealing with these models, named MultiLCIRT, is described. The models at issue extend traditional IRT models allowing for (i) multidimensionality and (ii) discreteness of latent traits, which allows for the detection of unobserved homogeneous groups (i.e., latent classes) of individuals. They also allow for different parameterizations of the conditional distribution of the response variables given the latent traits, depending on both the type of link function (i.e., local logit versus global logit) and constraints imposed on the discriminating and difficulty item parameters. Issues related to model selection are discussed in detail. A special attention is devoted to the dimensionality analysis and the aggregation of items in homogeneous groups (i.e., latent dimensions) is illustrated through a model-based hierarchical clustering procedure. Besides, the interpretation of the outputs of the estimated class of models is also discussed.
 
The topics at issue are illustrated through examples based on real data.
 
 
 
 
 
Tutti gli interessati sono invitati a partecipare.
 
 
 
 

 

 
 
 
 
 
 
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Francesca De Battisti
Dipartimento di Economia, Management e Metodi Quantitativi 
(III piano, studio n. 29)
Via Conservatorio 7
20122 - Milano
Tel: 02.50321464
Fax: 02.50321505
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