Lately I have been writing and talking quite a bit about PBL or project-based learning. As I mentioned previously my take on PBL is there are two types: (1) inquiry-based where students solve an essential question often in the shape of a lab or research project, and (2) design-based where students solve an essential problem often in the shape of a design challenge or engineering project.
If you are on the hunt for much more depth than this brief statement above, I recommend checking out the Buck Institute for Effective Education. They focus on PBL pedagogy, research and partnerships. They have a ton of white papers, some curricula, and other resources that can inform your teaching and learning.