The purpose of this study was to describe how four teachers in four different cities in Missouri implemented a constructivist-based learning environment (CBLE) that included an innovation cluster that paired an emerging online technology with a unit design framework. The motivating question for the study originated from prior research on teacher reform efforts including the adoption of technology innovations in the classroom, new theories of constructivist-based learning and the principles of professional development for educators implementing reform. Using a multiple case study research method, the researchers collected and analyzed data to (1) identify how effectively each of the teachers implemented the CBLE unit based on their goals for adopting the innovations while participating in online collaborative professional development and (2) identify cross-case issues that arose as the teachers implemented the unit. Conclusions in the study suggest that the teachers implemented innovation into their classrooms with varied levels of effectiveness based on their initial goals for the reform process. Aspects that influenced the effectiveness of their unit and the implementation of the innovation included (1) the teacher's ability to benefit from online collaborative professional development forums, (2) the teacher's problem-solving strategies for resolving conflict issues related to their local school environment, and (3) their prior conceptions about teaching and learning and their compatibility with the reform instructional pedagogy. (Contains 6 figures and 1 table.)