Administering design fluency tests in school-aged children: analyses of design productivity over time, clustering,...

This study investigated the effects of child-related factors (age, sex, and intellectual abilities) upon design fluency (DF) test scores. A DF test, a semantic verbal fluency (VF) test, and a Block Design test, as a proxy of intelligence, were administered to N = 80 healthy native Dutch-speaking children aged 8.45-12.82 years. Three components of DF performance were examined, i.e., design productivity over time, clustering (i.e., generating designs that share visual-spatial similarities, such as addition, deletion, or rotation), and switching (i.e., shifting between strategies that children use to draw the designs). The relation between DF design productivity over time and age was curvilinear, that is, improvements in test scores were much more pronounced for younger children than for older children. No (curvi)linear age effects were found in DF productivity scores, clustering, and switching. Also, our results did not reveal a relation between intellectual abilities and DF test scores. Furthermore, DF test scores and VF test scores were only partially significant, i.e., only significant positive correlations were found between the productivity scores of the VF test and the DF test. Finally, higher order sex by age interactions were found in all DF test scores, i.e., girls <10.5 years produced more designs, made longer clusters, and switched less than boys. Opposite sex differences were found for children >10.5 years. This illustrates the utility of combining quantitative scoring procedures with in-depth clustering and switching to understand interactions between age and sex during DF tests.