The Center for Evidence-Based Practice: Young Children with Challenging Behavior is a national research and training center funded by the U.S. Department of Education, Office of Special Education Programs (OSEP) to:

• determine effective polices and practices for preventing and/or addressing
  challenging behavior in young children birth through five years, and
• develop materials and training opportunities regarding those practices.

The Center has done substantial work in this area as is evidenced throughout the site.

http://challengingbehavior.fmhi.usf.edu/summit_home.htm

be sure to check all the links!