Two meetings titled „Analyzing PISA 2018 Data with the PISA Data Explorer and IEA`s IDB Analyzer” and “Item Response Theory and Population Modeling in Large Scale Assessments” took place at the campus of the Educational Testing Service (ETS) in Princeton from 29.7. to 2.8.2019. The first meeting from Monday untill Wednesday focused on general aspects of analyzing large scale assessment data, followed by hands-on use of the two above mentioned computer programs: PISA Data Explorer and IEA`s IDB Analyzer. The second meeting firstly discussed general aspects of test designs and which factors influence the selection of this particular test design. In the second part, hands-on activities on the Multidimensional Discrete Latent Trait Models (MDLTM) and the Direct Estimation Software Interactive (DESI) were conducted. Lisa Ziernwald attended both meetings and, through the lectures, discussions and hands-on activities, gained good insights into the special features of Large Scale Assessments in general and in depth insights into the data handling and data analysis of PISA 2018 data.