Adolescent vocabulary development: A longitudinal study of in-school and out-of-school predictors

It is not clear that we can substantially improve literacy instruction for adolescents without better understanding their vocabulary development. This study provides a longitudinal analysis of students' in- and out-of-school activities and examines how these activities predict vocabulary development using multiple regression and growth modeling techniques.; Seventh- and eighth-grade students (N = 291) completed surveys on two occasions to determine how much time they allocated to a range of literacy and other activities during the summer and school year. Student vocabulary and passage, sentence, and listening comprehension were measured at three time periods to establish an unconditional growth model of student vocabulary development. Demographic and survey data were used to predict vocabulary outcomes using multiple regression and growth-curve analysis.; There were several important findings from the analysis of change in vocabulary during the summer. The most general finding was that students tended to regress in word knowledge during summer months. Only one reading type, teen culture reading, independently predicted change in student vocabulary; it predicted vocabulary loss. Other activities were predictive of vocabulary change for some students, but not others. Both narrative reading and expository reading predicted improved vocabulary outcomes for students who scored well on the cloze task but not students who performed poorly on that measure.; During the school year all students tended to improve in their academic word learning. There were far fewer activities that predicted changes in student vocabulary; only independent narrative reading predicted improved spring vocabulary controlling for fall scores. Interestingly, during this period of time independent narrative reading predicted improved scores for students who did poorly on the cloze task, a result that is somewhat contrary to the summer findings.; Growth curve analysis demonstrated that percentage of days in school was an important predictor of student vocabulary growth. Growth trajectories of students of different gender and race were similar, as were the trajectories of students in different grade levels, although students in higher-grade levels started with higher vocabulary scores. Students whose parents spoke a language other than English at home showed both steeper regression during the summer months and a more marked improvement in vocabulary levels during the school year, relative to students whose parents spoke English at home.; Growth curve analysis also demonstrated that out-of-school reading predicted improved vocabulary scores during the summer and during the school year, but reading was clearly more beneficial during the summer. Learning activities also had contrasting impact in the summer and school year; in the summer these activities resulted in higher rates of vocabulary learning, during the school year they predicted reduced rates of learning. Reading in class predicted improved vocabulary levels, but reading for ELA was the best predictor of improved vocabulary scores, followed by reading for Science, Social Studies and Math class.