Teaching, and education in general, remain firmly rooted in the practices of the past and continue to resist the implementation of strategies and theories arising from educational research. Consequently, significant reforms have been slow to take hold in educational systems around the world. Much of the reluctance can be attributed to a widely-held misconception of the nature of learning. This project attempts to address this misconception through the development of Professional Development Learning Environments (PDLEs are a series of learning tasks and a video-based case study) embedded in an online learning environment that requires the collaboration of users to solve problems. To use a Problem-Based-Learning (PBL) approach in an online context requires a major paradigm shift as well as using tools that were not designed specifically for such a student-driven, process-centred pedagogical paradigm. This becomes a problem when online resources and systems are used for supporting in-service teacher in their pursuit of furthering their education. Although the current theories of learning and teaching may present the philosophical content of such courses, the online strategies used often conflict with the theory. To study the formal implementation of PBL as a social-constructivist pedagogical approach, into an online learning environment to provide the tools for e-learning that would be closer in design to the current thinking on the very nature of learning, the PDLEs were modified to become small reusable video clips with a structure designed to facilitate PBL and focus learners' attention on higher order thinking skills rather than specifically on content. These modified PDLEs are referred to as Problem-Based Learning Objects (PBLOs). The PBLOs were embedded into a prototype of a Collaborative Online Learning Environment (COLE) which was developed simultaneously. The entire system was pilot tested with small groups. Preliminary results show that although many technical difficulties remain to be solved, using the environment does show evidence of some effect on beliefs about personal theories of learning, causing shifts from technical issues to those surrounding processes of learning. Our preliminary research has called attention to the potential ability of PBLO/COLE to disrupt conventional, transmission-based conceptions of online learning as content delivery. At the same time, however, our preliminary work has also indicated that learners who are not used to the collaborative opportunities provided within PBLO/COLE may still hold traditional orientations to teaching and learning as a gold standard to which all other options are compared. A purposeful direction for our future research will entail working with learners in PBLO/COLE over a sustained period so that they may engage in an online experience grounded in principles of socio-constructivism.