Lawrence, J. F. (2009). Summer reading: Predicting adolescent word learning from aptitude, time spent reading, and text type. Reading Psychology, 30(5), 445–465. http://doi.org/10.1080/02702710802412008
Mostly low-income African American and Hispanic teens (N = 192) were tested in (a) passage comprehension, (b) vocabulary ability, (c) cloze task performance, and (d) listening comprehension in the spring and vocabulary in the fall. Students were surveyed about reading (a) narrative, (b) expository, (c) teen culture, and (d) online texts. Interaction terms created by the product of cloze task scores with the time and frequency of student narrative and expository reading were both significant predictors of fall vocabulary. Online reading was popular but did not predict vocabulary gains. Teen culture reading predicted vocabulary loss. Text type and student profiles both play a role in predicting fall vocabulary scores from summer reading.
Lawrence, J. F., Hinga, B., Mahoney, J. L., & Vandell, D. L. (2015). Summer activities and vocabulary development: Relationships across middle childhood and adolescence. International Journal for Research on Extended Education, 3(1), 71-93. http://dx.doi.org/10.3224/ijree.v3i1.19582