This documentation refers to the database of the 2nd TREE cohort’s (TREE2) as published in the 2023 data release (TREE, 2023). It outlines the statistical models and estimation methods employed for scale construction and the calculation of student scores based on questionnaire items. Furthermore, we discuss the various metrics and indicators of relevant scale propertiescompiled in the technical appendix for all scales implemented in the TREE2 baseline survey.
The focus of the scale reporting is on the internal consistency of the scales and on the comparability of the measurements across survey languages, survey modes and survey settings involved. With very few exceptions, the results indicate at least sufficient or high internal consistency and measurement invariance of the scales used.
A complementary documentation covering the scales employed in later panel waves can be found in the 2023 TREE2 data release (Sacchi & Krebs-Oesch, 2023). With the exception of a few additional metrics of longitudinal measurement invariance over panels waves (ibid., sections 3.6, 4.2), it basically relies on the methods presented in this report
