Evaluation
How to evaluate the workshop?
Knowing whether the workshop actually worked requires deciding beforehand what 'worked' means.
Evaluation is how you find out whether the session achieved what it was supposed to. That sounds obvious, but most workshops are not evaluated at all, or evaluated only by asking participants whether they enjoyed it. Enjoyment is worth knowing but it is not the same as effectiveness.
Good evaluation starts with the objective. If the workshop was meant to align a team on a decision, evaluation asks whether alignment happened. If it was meant to generate ideas, it asks whether usable ideas came out. Define the measure before the session, not after, when you are less tempted to shift the bar.
Evaluation can be immediate, through a quick end-of-session check, or delayed, checking in weeks later to see what changed. Both are useful; they answer different questions.