Using collaborative critical reflection as an index, this study examines the asynchronous and face-to-face discourse of 28 suburban Chicago elementary teachers developing problem based learning (PBL) curriculum. Statistical analysis of the corpus produced by the 2 mediums shows that the asynchronous online network emerges as the medium of choice for addressing more theoretical and reflective discourse related to PBL development. Where face-to-face collaboration was convergent task focused, the asynchronous discourse environment is more suited for divergent task outcomes. The results of this study will help those who facilitate learning in the online environment understand the capabilities of interactive technologies in supporting cognitively complex learning outcomes and determine the pedagogical structures that encourage those outcomes. (Contains 3 tables and 4 figures.)