We explore the use of the PRIMM methodology (Predict, Run, Investigate, Modify, Make) within a higher education introductory programming setting, particularly focusing on the three first three steps. Formative prediction questions on the effects of changes to HTML, CSS or JavaScript code are constructed by students using PeerWise system, based on their own investigation. Authenticity of the task is enhanced by presenting the peer prediction questions as pull requests to a GitHub repository, mirroring the code review process followed by professionals working within software development teams. We report on student engagement with the formative practical exercises and analyse the content of the questions they asked
