P3 is a transformed introductory mechanics course at Michigan State University that focuses on the development of scientific practices. The design team, as part of the P3 course design made explicit attempts to assess learning goals that can often be perceived as being a part of the hidden curriculum or considered difficult to assess (for example: learning to work productively in a group). This assessment is in the form of formative feedback with students receiving a numbered grade and reflective commentary based around their interactions in the classroom for the week. In this presentation, case studies formed from student interviews conducted at the beginning and end of the semester are discussed to highlight how the formative feedback received, effected changes in student interactions in class. The presentation also highlights students’ reflections on the feedback and how the effect it had on them changed over time.