This study investigated how professional development featuring evidence-based customization of technology-enhanced curriculum projects can improve inquiry science teaching and student knowledge integration in earth science. Participants included three middle school sixth-grade teachers and their classes of students (N = 787) for three consecutive years. Teachers used evidence from their student work to revise the curriculum projects and rethink their teaching strategies. Data were collected through teacher interviews, written reflections, classroom observations, curriculum artifacts, and student assessments. Results suggest that the detailed information about the learning activities of students provided by the assessments embedded in the online curriculum motivated curricular and pedagogical customizations that resulted in both teacher and student learning. Customizations initiated by teachers included revisions of embedded questions, additions of hands-on investigations, and modifications of teaching strategies. Student performance improved across the three cohorts of students with each year of instructional customization. Coupling evidence from student work with revisions of curriculum and instruction has promise for strengthening professional development and improving science learning. (Contains 6 figures and 8 tables.)