When students choose their topic or select how to present their work, they are more likely to take ownership over their work and/or feel confident demonstrating their knowledge. Giving students choice on assignments can also make grading more interesting for the teacher!
Too much choice can cause problems. Teachers should offer students a limited number of choices. Research suggests three to five options may produce the most satisfaction and motivation. You can have more options in your teacher tool kit, but only give them three to five at a time. For the next project, you can give them a whole new set of three to five choices. Keeping your projects new and exciting.
Below are links to some interesting studies regarding Project Choice.
Student choice leads to more motivation and learning (Patall, E. A., Cooper, H., & Wynn, S. R. (2010). The effectiveness and relative importance of choice in the classroom. Journal of Educational Psychology, 102(4), 896. )
Too much choice can lead to decreased motivation & satisfaction (Iyengar, S. S., & Lepper, M. R. (2000). When choice is demotivating: Can one desire too much of a good thing?. Journal of personality and social psychology, 79(6), 995. )
I have several Project Choice activities from the classroom I am willing to share and modify for your content! Let me know how I can help!