Professor Yves Rosseel (Ghent University) will be the co-promotor of the PhD project. The research group is an international, collaborative and productive research environment with 6 professors and 25 PhD students and postdocs, from diverse backgrounds (besides psychologists, for example, statisticians, physicists and engineers). It includes top-level researchers in emotion, relationships, work, and culture, working with cutting edge data collection and statistical methods. See https://ppw. kuleuven.be/okp for more information and for relevant publications.

Project

Many important research questions in psychology seek to uncover relations among psychological constructs that are not directly observable or ‘latent’ – that is, they can only be measured indirectly via questionnaires. For example, does social pressure to be happy increase or decrease wellbeing? And how does experiencing negative affect relate to satisfaction with life? Structural equation modeling (SEM) is the state-of-the-art to model these relations. When comparing such ‘latent relations’ across many groups (e.g., countries in a cross-national study), they likely differ among the groups (e.g., they may be culturally dependent). However, it is equally likely that some of the groups share the same relations such that ‘clusters’ of groups emerge with respect to these latent relations (e.g., clusters of countries with a similar culture). This PhD-project is part of an ERC Starting Grant that aims to develop novel mixture SEM methods for finding such clusters. For doing so, differences in how the psychological constructs are measured by the questionnaire items – for example, differences in item interpretation or translation – should be unraveled from the differences in the psychological relations of interest. This becomes especially challenging when the measurement model – indicating which questionnaire items measure which psychological construct – is not known a priori (i.e., it is exploratory rather than confirmatory). This project focuses on mixture SEM methods that tackle these challenges by optimizing the comparability of the psychological constructs’ relations while, at the same time, capturing clusters of groups with equivalent relations. These novel methods will give psychologists the tools to answer their important research questions, even when comparability across many groups is difficult. The project includes substantive applications of the novel methods and the development of user-friendly, open-source software.