Investigating the Academic Vocabulary Development of Spanish-English Bilingual Students in Middle School

This study examined the vocabulary development of Spanish-English bilingual adolescents (n= 98) from the end of 6th through the end of 7th grade in a dual language setting by looking at the patterns of growth in English and Spanish vocabulary post intervention and adding to the body of research on vocabulary development. Data were analyzed using descriptive statistics and Hierarchical Linear Modeling (HLM). At the first level (TIME), the analysis helped to describe the shape of each person’s individual growth trajectory and to examine within person variability. The analysis at the second level (STUDENTS) considered inter-individual differences in order to detect heterogeneity in change across individuals and to determine the relationship between predictors and the shape of each person’s individual’s growth trajectory. Evidence for study 1 ~ English Vocabulary Knowledge revealed that on average, students demonstrated significant growth in English vocabulary development. There was significant variation across students with regard to initial status but not with regard to rate of change. In addition, the conditional models suggested that ELL status and initial Spanish cognate knowledge were significantly associated with initial English vocabulary knowledge while English reading comprehension was not. Evidence from study 2 ~ Spanish Cognate Knowledge revealed that on average, students did not demonstrate significant growth in Spanish cognate knowledge. There was significant variation across students with regard to initial status but not with regard to rate of change. In addition, the conditional models suggested that while Spanish comprehension and initial English were significantly associated with initial Spanish cognate knowledge, the ELL status had no effect. Findings from this study align with evidence from previous vocabulary studies showing similar results on the lack of accelerated growth. However, unlike other studies, this study provides reasons to be optimistic about cross-linguistic relationships for Spanish-English bilingual students. The results of this study have implications for designing instruction for Spanish-English bilingual students that is inclusive of more explicit and sustained instruction in both Spanish and English in the area of vocabulary.