The purpose of a project-based activity is to relate an educational lesson to students outside of the traditional classroom instruction model by challenging students to work in groups and solve problems that hold meaning for the instruction in the "real world." Project-based activities allow students to solve problems with a hands-on approach, central concepts and principles of a subject, and these activities promote creativity, spontaneity and ingenuity.
Project-based activities can be short- or long-term, multi-step lessons where students divide up the work and responsibilities among themselves. Though the work is divided equally among students, the emphasis is on working together to complete a project. Students also typically present the project together and must communicate to the teacher and other students what they have learned.
There a number of elements of project-based activities that differ from traditional classroom instruction. Project-based activities are typically open-ended and concentrate on practical skills that students can relate to. Group feedback, teamwork and revision are also integral to project-based activities, whereas traditional classroom instruction is often done individually by students or outside of a group effort.
One criticism of project-based activities is that there is a lack of direct teacher oversight throughout the course of the project, which can result a weak project where not much is accomplished or learned. Another problem with the lack of oversight is that it can be difficult to ascertain who really worked hard, and how much work each student did on the project. A final criticism is that the presentation of the project -- a flashy poster or video -- can often overcompensate for a lack of research or group effort.