Open Skill vs Closed Skill success criteria

I have been reading Formative Assessment in Action By Shirley Clarke I found it interesting when reading about co-constructing success criteria with open and closed skills. When reflecting back to my target group of Year 8 boys I realised that they are confident in setting closed skilled success criteria. But still rely on support with open skills. This has made me aware of the power of good exemplars for the students to refer to with their success criteria when working with open skills. Alan Peat provides examples, teaching tips to help with co-constructing success criteria that I am finding useful at the moment.