Development of a Vocabulary Inventory for English-Mandarin Dual-Language-Learning Infants and Toddlers

Area of Science:

• Child language acquisition
• Bilingualism and multilingualism
• Psycholinguistics

Background:

• Accurate vocabulary measurement is crucial for understanding early bilingual language development.
• Existing tools may not fully capture the nuances of dual language acquisition.
• Research on language transfer and conceptual growth requires precise lexical data.

Purpose of the Study:

• To develop and validate the Dual Language Learners English-Mandarin (DLL-EM) inventories.
• To create a culturally responsive tool for assessing English-Mandarin infant and toddler vocabularies.
• To address limitations of existing instruments in measuring bilingual lexical development.

Main Methods:

• Quantified psychometric properties of DLL-EM using Item Response Theory with large datasets (Wordbank, Web-CDI).
• Administered DLL-EM to a sample of 30 toddlers to assess vocabulary composition and compare with existing measures.
• Expanded upon the MacArthur-Bates Communicative Development Inventories (CDIs) with translated equivalents and dialect options.

Main Results:

• DLL-EM inventories showed near-perfect correlations with estimated English and Mandarin CDI scores.
• The tool required approximately 15 minutes for administration.
• DLL-EM provided unique insights into toddlers' total and conceptual vocabularies, differing from non-matching CDI forms.

Conclusions:

• The DLL-EM is a valid and culturally responsive instrument for assessing English-Mandarin dual language learners' vocabularies.
• This tool is essential for researchers, educators, and clinicians studying bilingual development.
• DLL-EM facilitates accurate documentation of lexical acquisition in bilingual infants and toddlers.