Abstract
This study’s hypotheses were that (a) word-problem (WP) solving is a form of text comprehension that involves language comprehension processes, working memory, and reasoning, but (b) WP solving differs from other forms of text comprehension by requiring WP-specific language comprehension as well as general language comprehension. At the start of the 2nd grade, children (n = 206; on average, 7 years, 6 months) were assessed on general language comprehension, working memory, nonlinguistic reasoning, processing speed (a control variable), and foundational skill (arithmetic for WPs; word reading for text comprehension). In spring, they were assessed on WP-specific language comprehension, WPs, and text comprehension. Path analytic mediation analysis indicated that effects of general language comprehension on text comprehension were entirely direct, whereas effects of general language comprehension on WPs were partially mediated by WP-specific language. By contrast, effects of working memory and reasoning operated in parallel ways for both outcomes.
Notes
1 We focused on WM span involving digits and words. Although prior work indicates a role for visual-spatial WM (e.g., Boonen et al., Citation2013) and inhibition (e.g., Passolunghi et al., Citation2005), we omitted these due to time constraints and because they have not proven consistent predictors at this age range (e.g., Fuchs, Geary, Compton, Fuchs, Hamlett, Seethaler et al., Citation2010). We return to this omission in the discussion.
2 Statistical mediation seeks to identify a mechanism or process that underlies the relation between an independent and dependent variable. In a mediational model, the hypothesis is that the independent variable influences the mediator variable, which in turn influences the dependent variable, and that the indirect effect of the independent variable via the mediator on the outcome is also significant. Thus, the mediator variable clarifies the nature of the relation between the other two variables. For example, Fuchs et al. (Citation2013) found that student improvement in fact-based retrieval, not improvement in counting procedures, partially mediated the effect of speeded strategic counting practice on arithmetic outcomes.