A multidimensional pairwise comparison model for heterogeneous perceptions with an application to modelling the...

Pairwise comparison models are an important type of latent attribute measurement model with broad applications in the social and behavioural sciences. Current pairwise comparison models are typically unidimensional. The existing multidimensional pairwise comparison models tend to be difficult to interpret and they are unable to identify groups of raters that share the same rater-specific parameters. To fill this gap, we propose a new multidimensional pairwise comparison model with enhanced interpretability which explicitly models how object attributes on different dimensions are differentially perceived by raters. Moreover, we add a Dirichlet process prior on rater-specific parameters which allows us to flexibly cluster raters into groups with similar perceptual orientations. We conduct simulation studies to show that the new model is able to recover the true latent variable values from the observed binary choice data. We use the new model to analyse original survey data regarding the perceived truthfulness of statements on COVID-19 collected in the summer of 2020. By leveraging the strengths of the new model, we find that the partisanship of the speaker and the partisanship of the respondent account for the majority of the variation in perceived truthfulness, with statements made by co-partisans being viewed as more truthful.