Level 2Project 1 · Session 15
15

Project 1 · Your first real device

Test it and fix it

What we are making: nothing new. Today somebody else uses your device while you say nothing.

The test

  1. Swap with another team. Put your device in front of them and do not speak.
  2. Write down every moment they hesitate, touch the wrong thing, or ask what it does.
  3. Swap back. Fix the three worst things on your list.
  4. Then stop. No new features after today.
💡 Tip
‘They did not understand it’ is not a finding. If somebody cannot tell what your device is for or whether it is working, that is a fact about the device. Most of it is fixed by the screen: say what the reading means, not just what it is.

The three fixes that solve most of it

  1. A label on the device saying what it is and what to do to it.
  2. The screen says the meaning, not only the number. ‘22 C — OK’ beats ‘22’.
  3. Something that shows it is alive when nothing is happening — a dot that blinks, or the reading updating visibly.

Also today: the freeze

From now until the showing, no code changes and no rewiring. Every year, the devices that fail are the ones that were still being improved that morning.

Before you leave

  • Your observation list.
  • Three fixes, made.
  • A label on the device.
Challenge optional — only if you finish early
  • Test it on somebody who does not speak the language on your label.
14. Build it