TOSP sub-test Things which belong together maps pupils’ reliance on taxonomic versus thematic principles when categorizing objects.

Taxonomic categorizations are given a higher score than thematic categorizations for two reasons:

1. A preference for taxonomic categorization may be indicative of the positive effects of earlier education.

2. Pupils who have sorted objects and experiences in taxonomic categories will be better equipped to form hypotheses and predictions about their world, and thus, also draw new inferences.