For Level 4, students need to write a good evaluation that offers breadth and/or depth.
Their points could actually be quite brief but should be relevant and used to make a substantiated judgement in response to the question.
No judgement, or weak judgement would be a Level 1 response, and Level 2 responses would have a clear and developed judgement.
Guidance about this can be found in the mark schemes of the sample papers, and in the mark schemes for the exams themselves. Mark schemes for summer exams are added to OCR Interchange on results day.