Project based learning (also known as problem-based learning, inquiry based learning, simulation based learning, etc.) is a mode of teaching and learning carefully crafted around a defined problem or scenario. It’s roots are generally traced back to Dr. Howard Barrows, a professor of medicine at McMaster University in the 1960s.  Professor Barrows thought that medical education can be more engaging by presenting medical students with carefully constructed simulations involving make-believe patients. Barrows gave the medical students copies of lab results, descriptions of what the patient said and how s/he looked, xrays and the like and asked them to decide what should be done next. The students' task is to perform diagnosis and proscribe possible treatments. To make these decisions, students generally defined “learning issues”, "need to knows" and assigned different learning issues to different members of the group. Barrows was there to guide the deliberations, ask pointed questions, etc.

Today, problem based learning is alive and well in many classrooms.  It generally involves a scenario where students to assume specific roles (as research assistants, environmental advisers,  advocates, etc). to solve or address carefully specified real-world problem.