I am an assistant professor of methods and statistics within the Department of Child Development and Education at the University of Amsterdam.  My areas of expertise areas of expertise span structural equation modeling (SEM), multilevel modeling (MLM), social-relations modeling (SRM), and their intersections (i.e., ML-SEM and the SR-SEM), as well as nonparametric methods, Bayesian inference, and modern missing data methods. My methodological research interests involve statistical programming for psychometric methods. I am a coauthor of the R package lavaan, which is an open-sourse R package for SEM. I also develop key software in the "lavaan ecosystem" (e.g., as primary developer of the R package semTools, maintainer of the R package simsem, and contributor to the R package blavaan). 

My current research project involves scaling-up the lavaan project by improving its quality and expanding its scope to facilitate greater community involvement with its ongoing development. I lead a consortium of 12 researchers among 8 Dutch universities, funded by NWO via Open-Science NL. 

One of my previous research projects extended SEM by integrating it with the social relations model (SRM), which was funded by the NWO's Veni and Open Competition (XS) grants.  I used Bayesian methods to model "round-robin" (or "social network") data from the perspective of generalized latent-variable modeling, enabling many advantages of SEM to be applied to models for network data:

• simultaneously estimate a causal process (i.e., "mediation models")
• account for measurement error by using multiple indicators
• handle missing data using all available information (similar to FIML) or data augmentation (similar to multiple imputation)

A result of these projects was that I developed a new R package called lavaan.srm for the integrated SR-SEM using a lavaan interface. 

Expertise and Research Fields

• Latent variable models
• Psychometrics
• Statistical programming

Expertise and Research Fields

• Latent variable models
• Psychometrics
• Statistical programming

Research Methods

• Monte Carlo simulation
• Robust and nonparametric (e.g., resampling) methods
• Bayesian estimation and inference
• Modern and planned missing-data methods

Current Research Projects 

• Infra-Structural Equation Modelling: Advancing Open Software, Education, and Application of an Indispensable Theory-Testing Framework: an open-science infrastructure grant to scale-up the lavaan project, a critical open-science infrastructure for SEM development and application.
• Evolving models for dyadic network data to represent and test complex theories: a Veni grant to integrate social relations (SRM) and structural equation (SEM) models. This has been extended with a follow-up grant: Developing and validating a generalized structural equation model for social network data (an NWO Open Competition (XS) Grant).
• Reorienting methods that utilise the latent-response interpretation for categorical outcome variables: Viewing thresholds as a measurement model
• Developing a single gold-standard method to quantify all types of reliability, for all scales of measurement, on the same metric

Research Grants & Honours

• NWO / OS-NL grant 500.040.2516
• NWO grant 016.Veni.195.457
• NWO grant 406.XS.01.078
• UvA's SoBe DSC valorization grant
• UvA's SoBe DSC workshop grant
• UvA’s Grassroots programme
• Kohnstamm Foundation’s Fund for Educational Research

Courses Taught

For the Research Master I teach 2 courses: Methods and Statistics in Education Research and Structural equation modelling in educational research
For the Youth at Risk Master, I teach 1 course: Masterclass in  Methods and Statistics

PhD Supervision

1. A comprehensive framework for estimating and interpreting interrater reliability of (inter)dependent data | PhD candidate: Debby ten Hove, MSc
2. Non-standard applications of structural equation modelling in child development and education research | PhD candidate: Laura Kolbe, MSc