The relationship between vocabulary depth knowledge, word reading, and reading comprehension in Chinese

Although vocabulary depth (VD) is recognized as a crucial factor in reading comprehension, the investigation of its role in reading comprehension remains insufficient. This study aimed to address two significant research gaps in this domain. First, empirical evidence is needed to explore the construct of VD knowledge, particularly within the Chinese language. Second, the underlying mechanism that connects VD and reading comprehension requires further clarification. In this study, a sample of 326 native Chinese students from Grade 4 participated in a comprehensive battery of tests assessing VD knowledge, word reading, and reading comprehension. Based on theoretical frameworks of VD knowledge, we measured six subtypes of VD knowledge: polysemy, collocation, word register, part-of-speech, semanticassociations, and homonyms. The results of factor analysis revealed that Chinese VD knowledge can be conceptualized as a two-factor construct, encompassing in-depth semantic knowledge (VD-meaning) and knowledge of word usage (VD-usage). Both VD-meaning and VD-usage demonstrated significant direct effects on reading comprehension, highlighting the critical role of VD in determining reading comprehension outcomes in Chinese. Furthermore, our findings indicated an indirect contribution of VD to reading comprehension, specifically through the mediating effect of word reading on the relationship between VD-meaning and reading comprehension. This study represents a pioneering empirical investigation that delved into the construct of VD in Chinese. In addition, we discuss the role of VD knowledge and its interaction with word reading in the context of Chinese reading comprehension, which could significantly enhance our understanding of the underlying mechanism that links vocabulary knowledge to reading comprehension.