Test it

1. 5 min

   Swap devices. Say the silence rule and say why.

2. 15 min

   Watch someone use yours. Write down where they stop. Do not help.

3. 10 min

   Back to your own. Decide the single most useful change.

   What did you watch them do that you did not expect?

4. 10 min

   Make that one fix.

5. 10 min

   Boards out. Tick what moved from the middle column to the first.

• The narrator. An explained interface always works, which is why explaining destroys the only honest instrument in the room.
• Notes about what the partner said rather than what they did. What someone says can be shaped by who is listening; where they hesitated is not.
• Somebody whose thing works perfectly and who cannot explain any of it. Ask what they would change if one part had to go.
• Rewrites that grow past the one fix. One fix forces a decision about what mattered; an hour does not.
• Ticks on the boards, however few. That short list is the only evidence anyone has that they learned something, and it is in their own handwriting.
• Ask anyone whose partner sailed through what they had written on the fourth line of their card. Somebody who predicted where it would break has just watched their own check work, and that is worth saying out loud.

• Enforce the silence by standing next to the talker, not by repeating the rule.
• If a pair has already contaminated their run, swap them with another pair. The second run is still worth something.
• Ask anyone in that position to change one thing. That single request tells you both where they are, without a verdict.
• If the clock beats you, naming the fix is nearly as good as making it, and the board tick works as a verbal round. The silent watch is the one thing that cannot go; everything else here is commentary on it.

The print pack: this plan and its sheets

• board on its own
• drill on its own