Many teachers found it difficult to understand the academic research papers which set out the principles of effective feedback and distinguished between different types of feedback. (educationendowmentfoundation.org.uk)
For example, how many times have you shown your resume to people and gotten different types of feedback? (careersherpa.net)
It was least successful when teachers were unclear about the differences between different types of feedback, and when pupils were unable to set clear success criteria. (educationendowmentfoundation.org.uk)