The strategy, as published
Write "why might this be stronger with evidence?" not insert the evidence yourself. If feedback needs no effort from the learner, it is information, not feedback. Thinking is the point.
Find this under Help pupils act on feedback
Part of Feedback & the Learner in 03 Feedback, where it sits alongside its neighbouring strategies, the infographic and the thinking for the whole area.
Why you might use it
If a comment asks nothing of the pupil, it is information, not feedback. Wiliam's test is demanding: the measure of feedback is the thinking it causes, and a comment that does the pupil's thinking for them causes none.
Why might this be stronger with evidence leaves work for the learner. Inserting the evidence yourself finishes the job and ends the learning.
What it might look like
A computing teacher stops writing the fix beside broken code. Instead each comment names the symptom and asks a question: this loop never ends, so what condition would stop it? Pupils write the answer, then make the change.
Try it
Before returning your next set, reread each comment asking one question: what will the pupil have to think about to use this? If the answer is nothing, rewrite it.
What to notice
Things to think about
The wider thinking
This is Wiliam's contribution to the strand distilled: feedback exists to change the learner's thinking, and anything that bypasses the thinking bypasses the learning. The card’s attribution stands as published: Wiliam.
The fuller picture, sources included, is in further reading and evidence for Feedback.
Keep exploring
Back to this strategy in 03 Feedback, across to what you're trying to improve, or into all 144 at once.
Want to take this further?
Pedagogy First gives you a starting point. If you want support exploring how approaches like this can work across your school, trust or professional learning programme, that work is available.