“Research studies are needed to determine the efficacy of various types of professional development activities.” (Bransford, Brown, & Cocking, 1999, p. 240)
“Professional development matters only if it changes what teachers do with kids.” (Pianta, 2006)
The quotes above illustrate a pressing need to study the features and levels of professional development that are effective and feasible for increasing preschool teachers' use of evidence-based practices, particularly practices associated with improved learning outcomes for young children with disabilities.

A significant question requiring attention in the early intervention/early childhood area is:

The Impact of Professional Development on Preschool Teachers' Use of Embedded Instruction Practices project will help inform the field about which professional development (PD) approaches appear to be most promising for bridging the gap between research and practice. The project will produce a framework for developing PD intervention. Systematic and iterative procedures for developing and validating an intervention package (Tools for Teachers-TfT) will be demonstrated. Empirical data will be produced that offer feedback for refining TfT intervention components. We will have data to share about the feasibility of the intervention components, how these components work, and whether some components are more difficult to implement than others. We will learn whether providing teachers a theoretically and empirically supported PD intervention is related to their fidelity of implementation of embedded-instruction practices and if the type of follow-up coaching teachers experience is differentially effective. We also will learn whether a PD intervention focused on embedded-instruction practices is associated with improvement in child engagement and learning. These findings will contribute to the advancement of evidence-based PD practices in EC/ECSE. Finally, we will have qualitative data from three geographically distributed sites that might provide preliminary explanations related to contextual factors that are associated with the effectiveness of the PD intervention.

Pianta, R. (2006, May). Making early education opportunities work for kids and teachers: Professional development and classroom instruction. 2006 Harris Forum, St. Paul, MN. http://education.umn.edu/ceed/events/HarrisForum/2006HarrisForumTranscript.pdf

Bransford, J. D., Brown, A. L., & Cocking, R. R. (Eds.). (1999). How people learn: Brain, mind, experience, and school. Washington, DC: National Academy Press.