[Forum SIS] Prossimi seminari -DiSIA

[gottard]

DiSIA  (Dipartimento di Statistica, Informatica, Applicazioni “G. Parenti”)
Università di Firenze

- PROSSIMO SEMINARIO - 


Data:  15 novembre 2017, ore 12.00 aula 32

Davide Vidotto  (Tilburg University)  terrà il seguente seminario : 

Bayesian Multilevel Latent Class Models for the Multiple Imputation of Nested Categorical Data <http://local.disia.unifi.it/abstract-seminari.php?#134>

Multiple imputation of multilevel data (i.e., data collected from different groups) does not only require to take correlations among variables into account, but also to consider possible dependencies between units coming from the same group. While a number of imputation models have been proposed in the literature for continuous data, existing methods for multilevel categorical data, such as the JOMO imputation method, still have limitations. For instance, JOMO only considers pairwise relationships between variables, and uses default priors that can affect the quality of the imputations in case of small sample sizes. With the present work, we propose using Multilevel Latent Class models to perform multiple imputation of missing multilevel categorical data. The model is flexible enough to retrieve original (complex) associations of the variables at hand while respecting the data hierarchy. The model is implemented under a Bayesian framework and estimated via Gibbs sampling, a natural choice for multiple imputation applications. After formally introducing the model, we will show the results of a simulation study in which model performance is assessed, and compared with the listwise deletion and JOMO methods. Results indicate that the Bayesian Multilevel Latent Class model is able to recover unbiased and efficient parameter estimates of the analysis model considered in our study.

Referente: C. Rampichini




Tutti gli interessati sono cordialmente invitati a partecipare.



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Anna Gottard
Dipartimento di Statistica Informatica Applicazioni
Università di Firenze
V.le Morgagni 59, Firenze

gottard a disia.unifi.it
http://local.disia.unifi.it/gottard/
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