Class size was extracted from the fourth grade student lists providedby the Education Department, including also students who did notprovide any data in the assessment. Support was measured by askingclass teachers at grade six whether the student received tier 2intensified (n = 69) or tier 3 special support (n = 36). The informationwas not available for 77 students. As we used Maximum LikelihoodRobust (MLR) estimation for fitting the models, we used also the dataprovided by them, where applicable.For testing the hypotheses, we specified a two-level model withcross-level interaction effects. At the individual level, we predicted thesixth grade test score by the fourth grade test score and the fourth gradeanalogical reasoning. In addition, we added categorical variables fortier 2 support (0 = no support, 1 = tier 2 support) and for tier 3support (0 = no support, 1 = tier 3 support) as predictors. At the classlevel, we used the average fourth grade performance level, class sizeand the proportion of students receiving tier 2 or tier 3 support (meanfor all tier 2 and tier 3 students) in a class as predictors. Additionally,we calculated cross-level interaction effects for class size and tier 2 andtier 3 support.