This formative experiment explored the extent to which two instructional frameworks that varied in the explicitness of academic vocabulary instruction, comprehension strategy instruction, and supports for student autonomy influenced reading comprehension, vocabulary acquisition, perceptions of autonomy supports, and reading engagement in fourth-grade English-language learners (ELLs). In the contextualized vocabulary instruction (CVI) framework, four reading comprehension strategies were integrated with two autonomy-supportive (motivation) practices and implicit instruction of academic science vocabulary. In the intensified vocabulary instruction (IVI) framework, students experienced explicit instruction of academic science vocabulary in relation to reading, without explicit strategy instruction or attention to autonomy supports. Results indicated that the IVI framework increased students' academic vocabulary even 3 weeks after the intervention was over, whereas CVI benefited students' reading comprehension as well as their perceptions of autonomous learning in the classroom. Both quantitative and qualitative results are interpreted under the lens of formative experiments. (Contains 8 figures.)