I held an after school workshop on PBL and tried to recruit teachers to work with me to create a project.
A teacher challenged “Is there any research out there to support PBL and its positive impact on student achievement?”.
Got anything?

There is lots of evidence that PBL works well for all students and settings, IF it is well-designed and well-implemented (like everything else)! Check out our website’s Research section.

Thanks. I’ll send this teacher to your link.

This is an area requiring much more solid research.  The best comprehensive study I’ve found doesn’t refer to PBL per se, but students in the study are doing a lot of PBL.  Hope it is useful.

Authentic Intellectual Work and Standardized Tests:  Conflict or Coexistence?
Newmann, Bryk & Nagaoka, 2001, Consortium on Chicago School Reform

http://ccsr.uchicago.edu/content/publications.php?pub_id=38