Welcome to my R repository

This repository will provide some examples from my daily R workloads and parts of my PhD studies. Like everyone in the field of educational psychology, I dealed with challenging statistical problems. I will report about them.

Specifying a multi-group longitudinal CFA

This example shows you how to use lavaan, knitr, semTools, kableExtra and psych to generate a multi-group longitudinal CFA. Additionally, the examples shows you how to automize the necessary table production for the results of the measurement invariances testing. It was used as a part of thesis, written with bookdown. The output table looks similar to this:

Specifying a multi-group latent growth modell

This example how latent growth models can be established with lavaan. The model specification is based on:

• Little, T. D. (2013). Longitudinal Structural Equation Modeling. New York: Guilford Press.
• Grimm, K. J., Ram, N. & Estabrook, R. (2016). Growth modeling: Structural equation and multilevel modeling approaches. Guilford Publications.
• Wu, A. D., Liu, Y., Gadermann, A. M. & Zumbo, B. D. (2010). Multiple-indicator mul- tilevel growth model: A solution to multiple methodological challenges in longitudinal studies. Social Indicators Research, 97 (2), 123–142. doi:10.1007/s11205-009-9496-8

Dealing with DIF-analysis

The following example shows, how I used pairwise for my DIF analysis. In a first step, I recoded my Likert scales with car. The scales need to start with zero. In the example, these are five. In addition, the example shows the automated export of four DIF analyzes in a combined graph in pdf format and calling the export using R-markdown or bookdown combined with knitr.