This study comprises a randomized controlled trial to examine 1) the effectiveness of TeachTown: Basics, one of the only evidence-based computer-assisted intervention (CAI) packages for students with autism; 2) the extent to which teachers implement TeachTown the way it was designed; 3) the effects of its use on other evidence-based practices; and 4) organizational and teacher variables that mediate changes in the use of evidence-based practices when TeachTown is introduced. While there has been a rush to take advantage of CAI, there is little research on whether it will result in better outcomes for student with autism, and be feasible or sustainable in community settings. While CAI has the potential to increase instructional time for students with autism, it may result instead in teachers reducing their use of other evidence-based practices, including the amount of interpersonal (as opposed to computer) instruction students receive. While the related constructs of exnovation, de-implementation and de-adoption have been used to describe this phenomenon for more than 30 years, they rarely have been systematically studied. The proposed study takes advantage of an ongoing rollout of TeachTown in the School District of Philadelphia. TeachTown includes a computerized instruction component, combined with offline, interpersonal instruction between the student and teacher. It is not known whether public schools have the resources to implement programs like this, regardless of their efficacy, or whether or how teachers will incorporate them into the instructional day. An especially important question is whether existing evidence-based practices are exnovated as TeachTown is implemented. To address these questions, we rely on our longstanding collaboration with the School District of Philadelphia, the 8th largest school district in the US. At the beginning of the school year, we will inventory relevant technology and observe how it is used in the District's 83 kindergarten-through-second-grade autism support classrooms. We also will survey teachers and school administrators about expectations, support and rewards for using these technologies and attitudes, norms and self-efficacy regarding the use of these technologies. We then will use a waitlist-control randomized design to examine TeachTown's effects on student outcomes and use of other practices. We will unpack the impact of the implementation of TeachTown on existing evidence-based practices using direct observation and through qualitative interviews. The waitlist design allows the district to roll out the intervention to all classrooms, which is their intent. It also allows s to increase our sample to study moderators of sustainment of existing EBPs when a new technology is introduced. The proposed study would be one of the first to examine longitudinally the uptake of new technology for children with ASD in school settings, and the first to address use of CAI. Successful completion of this study will identify malleable targets for intervention to increase the use of CAI, should that appear warranted, while sustaining existing EBPs for children with autism in community settings.