Ask straight after a workshop, while people still remember it. These questions cover the content, the person running it, the pace and the practical side, and end with what people will actually use, which is the real test of a workshop.
We've ticked a short starter set. Change it to suit you.
Overall
Content
The facilitator
Practical details
Using what you learned
6 questions selected
Tips for a better workshop feedback survey
Hand out the QR code in the last five minutes; many people won't answer once they've left.
Read the level and pace answers together. If both are split, run two versions.
Ask “what will you do differently” again a month later to see what stuck.