Doctoral Dissertation Research: Contributions of cross-language semantic density to word learning in bilingual toddlers

This doctoral dissertation project examines how young children learning two languages acquire new words and connect them to their existing vocabulary. While bilingual children often know fewer words in each language compared to monolingual children, their combined knowledge across languages can match or surpass that of monolingual peers. This project tests whether the way words are organized in the brain helps bilingual children learn new words, focusing on organization due to shared meanings or related concepts. By studying bilingual toddlers, this research informs how children link their knowledge across languages, providing insights into early language development. The findings may advance strategies for teaching vocabulary to bilingual children, helping parents, educators, and caregivers support language learning in ways that build on children’s existing strengths. This project involves bilingual toddlers from diverse communities. Other benefits to society include providing educational and workforce development opportunities for undergraduate research assistants. This project examines how the connections between words in one language influence learning in the other language. For example, a child who knows many words about animals in one language may find it easier to learn new animal-related words in the other language. This research examines two types of words, completely new words (that require learning both a concept and a label) and translation equivalents (words for the same concept in both languages). Testing is conducted virtually, which increases access for families who might not otherwise participate in research studies. This work (1) advances a scientific understanding of how bilingual children leverage cross-language semantic density to learn new words and translation equivalents, (2) contributes new knowledge to theories and models of bilingual word learning, accounting for cross-language semantic density, and (3) informs models of bilingual instruction, potentially extending their application to an earlier developmental age. This award reflects NSF's statutory mission and has been deemed worthy of support through evaluation using the Foundation's intellectual merit and broader impacts review criteria.