What is the prime motivation/incentive for people to supervise undergraduate projects? Students want the degree obviously, but what do the supervisors get? Is there some incentive? Are undergraduate supervisors paid per project as well? I am an undergraduate computer science student. We mostly make applications and computer programs as final year projects.
Sometimes undergraduate projects can form an extended talent scouting, looking for good matches of personality and interests for future graduate students.
Beyond a general desire to train students to be good researchers, a few of the benefits of undergraduate supervision for the academic include:
Workload: Some departments have a workload model with various degrees of formality. In such models, supervising undergraduate projects would count towards an overall workload. Thus, if you preferred supervising undergraduate projects to some other tasks such as teaching or various service roles, you could do a little more. In a similar way there might be a default expectation that each member of academic staff take on a certain number of undergraduate students.
Facilitating research: Some undergraduate research is publishable. Thus, the research can contribute to the academic's research track record. Obviously undergraduate students don't usually have the research skills of a PhD student and the time frame is shorter. That said, with proper design of projects and some work by the supervisor, it's often possible to get a publishable research project or perhaps a piece of a publishable project. In other cases, merely supervising a project keeps the supervisor thinking about a project.
Identifying potential doctoral students: It provides an opportunity to get to know a student and identify those with particular research talents. Such students may consider doing a PhD.
In community/junior colleges, faculty members may be offered a small fee for supervising student's honors projects. In my experience, most of those who agree to do this put in far more work than would be covered by the stipend. Although some may agree to supervise projects just because they are expected to, most do so because they enjoy working individually with motivated and talented students.