I just want to add: Yest we can detect the people who are cheating in a very obvious way and remove those votes. But it’s hard to detect with confidence for smaller scale cheating. You will have people who might try to create one or two additional accounts to give themselves a little boost, which is unfair for those who don’t believe in cheating.
Additionally, rating systems only work at scale: when you have thousands of independent data-points. That will help eliminate any noise and give you a high confidence that the average rating represents the project. In your case, there’s probably a small chance that the projects for your class are going to be receiving a large number of independent ratings. The number of independent people seeking out school projects on our platform is not high. So you’ve effectively told your students to go reach out to their network of friends & family to get them to vote for them. You’re rewarding the students resources, not their work.
This is a completely unfair way to handle a school bonus, so I strongly recommend you find another way to handle it.