peripherals (i.e., digital cameras and scanners) are generally referred to as technology and efforts to utilize technology in the instructional environment generally described as technology integration. While there is disagreement about the importance of technology use in schools, about the variables most strongly impacting its use, and about what the long-term impact of computers on schools and on student learning will be, there is agreement that the meaningful use of computers in schools hinges on the professional development of teachers (Glennan & Melmed, 2000). In the following pages, we make the case that effective professional development for teachers focused on technology integration is hard to find. We then describe the Teacher Institute for Curriculum Knowledge about Integration of Technology (TICKIT) and present research that supports the claim that it was effective in changing teacher practice. The last sections of the article explain why TICKIT worked so well. To do this, we present the design elements of TICKIT against the backdrop of situated learning theory. We hope that university and K-12 educators interested in designing professional development for teachers in the area of technology integration will find insight for the design of their programs from the TICKIT model.