Educational Evaluation and Policy Analysis Month 201X, Vol. XX, No. X, pp. 1–21 DOI: 10.3102/0162373714557519 © 2014 AERA. http://eepa.aera.net SEVERAL challenges present themselves as barriers to our understanding of how professional development (hereafter referred to as PD) influ- ences change in schools (Correnti, 2007). One challenge is simply that most research on PD has been cross-sectional and thus examines a single point in time. With cross-sectional analyses, it is difficult to understand changes in practice because change presumes we have a measure of where teaching began before the PD was intro- duced. Cross-sectional analyses also fail to account for changes accrued over time (i.e., changes that might occur in the future because of teachers’ reflection on their PD experience). In addition, it is equally challenging to isolate effects of PD as conditions in schools are con- stantly changing, making different affordances available to teachers all potentially contributing to their learning. As these affordances, including curricula, leadership, access to expertise, social networks, visions of high-quality instruction, and so on, change frequently with new reforms and policies, the unique contribution of PD remains difficult to isolate (Knapp, 2003; Wayne, Yoon, Zhu, Cronen, & Garet, 2008). Variation in imple- mentation of the PD in different school sites cre- ates another challenge in PD research. When PD programs are delivered in several schools through a train-the-trainer approach, implementing PD with fidelity to its original design becomes an issue (Berends, Bodilly, & Kirby, 2002; Hamilton et al., 2003; Stein et al., 2008; Wayne et al., 2008). Variation in fidelity is a problem espe- cially from a statistical standpoint because it cre- ates uncertainty about the extent to which observed changes in instruction are due to the PD 557519EPA XX X 10.3102/0162373714557519Kisa and CorrentiLongitudinal Effects of PD on Teachers’ Practice research-article 2014 Examining Implementation Fidelity in America’s Choice Schools: A Longitudinal Analysis of Changes in Professional Development Associated With Changes in Teacher Practice Zahid Kisa Richard Correnti University of Pittsburgh The research on professional development (PD) consists mostly of studies utilizing cross-sectional data. We examined effects of change in school-level PD on change in teachers’ practice longitudi- nally. Using survey reports from 1,722 teachers in 31 schools implementing a popular comprehen- sive school reform (America’s Choice), we found that although schools were implementing the same reform model, they varied in their implementation of PD. Teachers successfully changed their practice toward reform-aligned instructional goals only in schools demonstrating high growth in providing reform-aligned PD (both in the content and process of their PD). Our findings have impli- cations for understanding interventions in schools and for thinking about the rigor of PD effects on teaching. Keywords: educational reform, professional development, instructional practices, school/teacher effectiveness at UNIV OF PITTSBURGH on January 22, 2015 http://eepa.aera.net Downloaded from