Chapter 2 of 7
Find out if you're wrong, before you build
Learn to see the beliefs inside every idea, and to find out which ones are wrong before you build. By the end, you can turn any feature request into a few small tests.
- 7 lessons
- A game, a thought experiment and a skills check
- Free, no sign-up
What you'll learn
- 1 Find the beliefs behind an idea
Every idea rests on beliefs nobody has checked. Learn to find them, and to ask what would prove each one wrong.
About 20 minutes
- 2 Turn a belief into a test
Six plain questions that turn a belief into a test, with a number and a date to decide.
About 19 minutes
- 3 Test the riskiest belief first
Which belief to test first: the one that kills the idea, has the least proof, and others depend on.
About 20 minutes
- 4 Match the decision to the evidence
How much proof a decision needs, and what to do when you have to decide before you have it.
About 20 minutes
- 5 Run a test in a day
Five cheap tests, what each one can and can't tell you, and who pays if a test goes wrong.
About 22 minutes
- 6 Test your skills
Check the key words, then use all five lessons on a new case. One score at the end.
About 21 minutes
- 7 Make your assumption map
The chapter's project: the beliefs inside a real feature request, ranked, with three tests.
About 31 minutes
By the end of this chapter
What you'll make: An assumption map
One page for a real idea or feature request. The beliefs it rests on, ranked by risk, and three of them turned into tests you could run.
You make it in lesson 7See what goes in it
Take a real idea or feature request, from your own work or from the chapter. Write one page, in plain sentences.
- The beliefs. Every belief the idea depends on, one per line, each starting “We believe that”.
- Rank them. For each belief: how much proof you have, as a rung from 0 to 6. If it is false, which other beliefs stop mattering? Then the one you test first, and why.
- Three tests. For your three riskiest beliefs: what you change, for whom, and what they will do. Why they would. The result that means you’re wrong, and the date you decide.
- The first test. What you will do this week, and who has to agree. The rung it can reach, and the decision that rung can carry.
Along the way: The 2-4-6 game, a thought experiment from Peter Wason, 1960, with Karl Popper's idea of testing.