Title: Leveraging Dynamic Structural Equation Modeling for Analyzing Intensive Eye-Tracking Data: Illustration and Software Development Author: Benedikt Langenberg Abstract: Consider an eye-tracking experiment that analyzes reading skills in children. Vast amounts of data are generated with multiple measurements of the eyes’ position per second. Reading is a complex and dynamic task, where words can affect the processing of the next words (both facilitate and hinder). Dynamic structural equation modeling (DSEM) has increasingly gained attention in the analysis of intensive longitudinal data (ILD), offering insights into diverse psychological processes' dynamics. However, DSEM's application has been largely confined to ecological momentary assessment, experience sampling, and diary data. This presentation aims to demonstrate DSEM's application in analyzing ILD from neuropsychological experiments, specifically in an eye-tracking experiment encompassing 267 children. The outcome of interest was the improvement in reading skills over the course of four years. Emphasizing the necessity of accounting for dynamics, this presentation reveals substantial bias in effect estimates when disregarded. Additionally, DSEM provides novel insights into interindividual differences in the dynamic nature of reading. The presentation culminates in introducing a user-friendly small-scale R software package, serving as an interface to the well-known Mplus software, facilitating DSEM estimation for experimental data.