This final report/doctoral dissertation describes activities and accomplishments of Project LIFT (Looking at Intervention Factors with Teachers), which assessed the relationships among classroom intervention acceptability, integrity, and effectiveness. Two studies were conducted. The first involved observing interventions implemented in 10 Iowa elementary classroom settings. In the second study, 350 elementary teachers in 11 states were surveyed with a project-developed questionnaire concerning their experiences and perceptions of interventions they have implemented with students. Findings from both studies indicated that teachers tended to receive assistance when developing an intervention, but then implemented the intervention alone. Individualized intervention plans rarely described specific steps to be completed. Most teachers rated the interventions from moderate to very acceptable in both studies and implementation integrity was found to be high in the observation study. Teachers responding to the survey indicated more use of formal efforts to maintain intervention integrity than teachers in the observation study actually used. Appended are interview forms used in the observational study, the questionnaire used in the national survey, and factor analysis results. (DB)