shift-abstraction-level

Steps

1. What must be done, and at what level is the subject stated?

Name the act the subject must support: decide, explain, build, or fix. Name the level it is stated at: does it say why, what, how, or which one?

2. How does it read a few rungs above and a few rungs below?

Write two or three restatements above it, each saying why the rung below matters or what it is a kind of, and two or three below, each saying how or which one. One line per rung. Leave the rungs unexamined until the next step.

3. What does each rung let you do, and what does it hide?

For each rung, name the act it makes possible and the detail it buries or lacks.

4. Which rung do you act at?

Choose the rung with the least detail that still supports the act. Under time pressure, start higher. To explain a fault, work up from the lower rungs; to work out how something should function, work down from the top.

Output