J. EDUCATIONAL COMPUTING RESEARCH, Vol. 41(2) 125-153, 2009 DEVELOPING CRITICAL IMPLEMENTATIONS OF TECHNOLOGY-RICH INNOVATIONS: A CROSS-CASE STUDY OF THE IMPLEMENTATION OF QUEST ATLANTIS* MICHAEL K. THOMAS University of Wisconsin–Madison SASHA A. BARAB Indiana University HAKAN TUZUN Hacettepe University ABSTRACT This study examined the tensions surrounding the implementation of a technology-rich educational innovation called Quest Atlantis (QA) in a local public elementary school. Three qualitative case studies of three classrooms implementing the innovation and a subsequent cross-case analysis were undertaken to illuminate: 1) the reasons why teachers chose to implement the innovation in their classrooms; 2) the core challenges and tensions of imple- menting this innovation; 3) the supports necessary to successfully implement the innovation; and 4) the adaptation that the innovation underwent in the course of its implementation. The results of this study indicated that teachers implemented QA because of its alignment with their existing curricular goals, its flexible adaptivity, and its emphasis on social commitments. Findings also indicated that teachers persisted in using QA because the students *This research was supported in part by a National Science Foundation CAREER Grant 9980081, and by a National Science Foundation Grant 0092831. 125 Ó 2009, Baywood Publishing Co., Inc. doi: 10.2190/EC.41.2.a http://baywood.com