The Institute for Statistics and Mathematics is pleased to invite you to this semester’s first research seminar, taking place on campus with the following two talks:

• Andreas Groll (Faculty of Statistics, TU Dortmund University)
  Fitting Regularized Partially Ordinal Regression Models With Don’t Know Option Within the GAMLSS Framework
  
  Wednesday, October 13, 2025, 17:00, Building D4, Room D4.0.136
  
  Abstract:This work deals with an extension of generalized additive models for analyzing regression data when the dependent variable is expressed by means of a partially ordered Likert scale including the "don't know" option. The proposed approach introduces a bivariate latent structure that jointly models the "don't know" decision and the subsequent ordinal response, allowing for flexible non-linear covariate effects and regularization. A central contribution is the use of regularization techniques to perform covariate selection and to distinguish informative predictors from noise in the presence of high-dimensional categorical variables. Estimation is carried out via a GAMLSS-based framework, enabling the combination of smooth terms, LASSO and LASSO group penalties, and fusion penalties. The model is evaluated through a simulation study and applied to the Italian Survey on Household Income and Wealth (SHIW), highlighting the role of geographic disparities and sociodemographic characteristics in shaping self-perceived income instability and the choice of the "don't know" option.

Please note that currently there are no Zoom streams planned for the talks in this semester.
For further information (such as related papers, linked software etc.) and the seminar schedule, please see:
www.wu.ac.at/en/statmath/research/resseminar