The purpose of the study was to examine how the processes and different activities that adolescent English L2 writers engage in producing multimodal texts influence the development of their multimodal and writing competence. This dissertation fills existing gaps regarding how multimodal pedagogies are implemented in L2 contexts to facilitate adolescent L2 writers' development of writing and multimodal competence.

The research was conducted in an English classroom within a junior high school (JHS) located in a small village in southern Ghana. Forty-eight second year JHS students (the equivalent of 8th grade) participated in the study; three of these were selected as focal students. Both qualitative and quantitative data were collected concurrently through an embedded, developmental case study design, with the quantitative data playing a supportive role. Data collected through this design included surveys, multiple drafts of students' expository texts, posters, poster presentations, guided reflections and text-based interviews.

The qualitative and quantitative analysis of the data showed that the adolescent L2 writers' mediated, distributed and complex multimodal activities created opportunities for developing new intellectual tools, strategic competence, and technical knowledge about multimodal composing as well as an in-depth understanding of, and interest in, social and cultural issues that affected the writers and their communities. The qualitative and quantitative analyses of the multiple drafts of the writers' expository texts also suggested that the multimodal activities helped the writers to improve the development and organization of their ideas and the overall quality of their paper.

These findings offer new insight and ways to think about how L2 teachers can develop students' academic language by helping students draw on ideas from their multimodal texts to revise their word-based expository texts and other genres of writing. Next, not only does this research help to expand the definition of adolescent English L2 writing competence beyond word-based composing, but it also provides an empirical evidence of how this reconceptualization can play out in concrete adolescent English L2 writing contexts. Finally, by bringing together multiple theoretical and interdisciplinary perspectives, this study offers a new framework for examining transformations in students' understanding of multimodal meaning making.