There is no one-size-fits-all solution for increasing student engagement in the classroom, but some research-backed strategies include:

1. Building relationships: Creating a positive, supportive learning environment where students feel connected to their teachers and classmates can help increase engagement.

2. Providing choice: Allowing students to make choices within the curriculum, such as selecting topics for projects or determining their own learning goals, can increase their investment in the material.

3. Incorporating technology: Using technology, such as educational games, simulations, and interactive whiteboards, can make learning more dynamic and engaging.

4. Using active learning strategies: Engaging students in hands-on activities, group work, and discussions can help them retain information better and be more invested in the material.

5. Giving immediate feedback: Providing students with timely and specific feedback on their progress can help them see the value in their work and feel more motivated.

These strategies are based on the principles of cognitive science and the ways in which people learn best.

Here are a few references for further reading:

1. The Community for Accredited Online Schools. (2021). 50 Strategies for Increasing Student Engagement.
2. Freeman, S., Eddy, S. L., McDonough, M., Smith, M. K., Okoroafor, N., Jordt, H., & Wenderoth, M. P. (2014). Active learning increases student performance in science, engineering, and mathematics. Proceedings of the National Academy of Sciences, 111(23), 8410-8415.
3. Marzano, R. J. (2018). The art and science of teaching: A comprehensive framework for effective instruction. ASCD.