A prototype is a question made visible. It does not need to persuade everyone; it needs to help a group see what is missing, what is working and what decision should come next.

One question at a time

An effective prototype begins with a precise uncertainty. The narrower the question, the more useful the answer we receive.

Reducing scope does not mean reducing ambition. It means getting a signal before investing energy in the wrong direction.

Observable feedback

Asking “do you like it?” produces opinions. Asking someone to complete a task produces clues. Behaviour shows where a design communicates and where it forces people to guess.

Notice pauses and shortcuts without immediately explaining the interface. They are the most valuable material in the session.