Direct and Indirect Effects of Phonological Ability and Vocabulary Knowledge on Math Performance in Elementary School

The main aim of this study was to estimate direct and indirect effects of phonological ability and vocabulary knowledge on subsequent mathematics and reading performance. To achieve our goals we used two-wave longitudinal data from the international Performance Indicators in Primary Schools (iPIPS) data set, which was produced in Russia in 2015-2016. We used rhyming skills and ability to repeat words/pseudowords as indicators of phonological ability, and identified three types of mathematical skills (digit identification, number manipulations and formal math). The results of our analysis confirmed the predictive role of preschool phonological ability as a domain-general precursor of later achievements. Phonological ability had a positive direct and indirect effects on the subsequent reading and math performance. Moreover, the direct effect was higher than the indirect effect. Reading fluency mediated the effect of phonological ability and did not mediate the effect of vocabulary knowledge. Vocabulary knowledge had insignificant direct effect on math achievement and positive indirect effect via phonological ability