The purpose of the proposed study is to investigate progress in the state of substance use prevention practice in the nation's middle schools. The study will build on an earlier study (NIDA R01 DA11492) that surveyed, in 1999, lead prevention teachers and school district coordinators in middle school - school district dyads. Returning to our original sample and using a Web-based data collection strategy, we will administer two additional rounds of data, in 2004 and 2007, from our respondent dyads. We will collect information to elucidate three major processes that are key to the dissemination of evidence-based curricula in school contexts. These processes are: (1) adoption, which refers to an organization's initial decision to select an innovative program; (2) implementation, which concerns how the program is actually implemented in a particular context and which encompasses both fidelity, or the degree to which programs are administered as intended, and adaptation, which refers to modifications to the program's content or didactic methods; and (3) sustainability, which concerns the degree to which the program becomes embedded in its host organization over time. Using the three rounds of data from 1999, 2004, and 2007, we will investigate: (1) changes over time in the prevalence with which evidence-based substance use prevention curricula have been adopted by the nation's middle schools and school districts, (2) changes over time in the quality of implementation of evidence-based substance use prevention curricula, (3) the degree to which the nation's two preeminent evidence-based curricula, Project ALERT and LST have been implemented with fidelity, and how they have been adapted in the classroom, and (4) factors related to the sustainability of these curricula and of evidence-based prevention curricula in general. Study results will shed light on the effects of the "No Child Left Behind" legislation, enacted in mid-2002, which provides local education authorities the opportunity to transfer to other priorities up to 50 percent of funds allocated to Safe and Drug-Free Schools.