“…Based on the state of research on relative accuracy , we assumed a positive relation of medium effect size between EC teachers' judgment of the mathematical skills of children and these children's skills, identified via an estimation of random slopes (Research Question (RQ) 1a). That is, with respect to the rank component of judgment accuracy, we assumed that children with higher scores on a well-established standardized test of their mathematical skills (“Mathematische Basiskompetenzen im Kindergartenalter,” MBK-0; Krajewski, 2018 ) also showed higher scores on a well-established tool used by teachers to evaluate skills of children (“Kinder Diagnose Tool,” KiDiT; Walter-Laager et al, 2011 ; for details about both instruments and the model estimated, refer to the Methods section below).…”