Quantifying vocabulary learning belief and strategy-A validation study of the Vietnamese version of Gu's (2018) vocabulary learning questionnaire

Background: The field of language teaching and learning has long recognized the role of vocabulary knowledge in all aspects of language proficiency and indicated that vocabulary beliefs and learning strategies play a pivotal role in learners' vocabulary development. As a result, understanding learners' beliefs and strategies in vocabulary learning is of paramount importance to language teachers. The Vocabulary Learning Questionnaire (VLQ) developed by Peter Gu in 2018 could be considered the most recent, validated instrument for the measurement of vocabulary learning beliefs and strategies. However, the VLQ contains too many items and is only available in English. The objectives of the study, therefore, are (1) to develop and validate a Vietnamese version of the VLQ which can exclude construct-irrelevant noises related to L2 comprehension, and (2) to reduce the number of items while retaining the key factors in the instruments. Methods: 722 Vietnamese university students took part in the study. Exploratory factor analyses (EFA) and confirmatory factor analyses (CFA) were examined with the free software Jamovi 2.3.13. Both Cronbach's alpha and McDonald's omega were employed to evaluate the factors' internal consistency. Results: Separate EFAs confirmed the two dimensions of vocabulary beliefs, explaining 62.6% of the total variance, and seven factors of vocabulary strategies, predicting 72.1% of the total variance. CFAs confirmed the hypothesized 9-dimensional structures of different vocabulary learning beliefs and strategies and offer cross-validation evidence for the Vietnamese VLQ. Reliability metrics demonstrated acceptable internal reliability for vocabulary belief and strategy sub-scales. Conclusion: The Vietnamese VLQ provides a validated measure of vocabulary beliefs and strategies. The 30-item version of the Vietnamese VLQ serves as a starting point for future research in the field of vocabulary learning and teaching in Vietnam.