Fermi Estimation Diagnostic Test
A Fermi estimation diagnostic test for target clarity, decomposition, assumptions, units, arithmetic, ranges, and sanity checks.
Candidates who need to find their weakest estimation behaviors.
Use one prompt as a diagnostic
A single estimation prompt can reveal whether the problem is target definition, assumptions, units, arithmetic, range, or communication.
Score the process
Do not score only final accuracy. Give separate marks for target, factor tree, assumption plausibility, unit consistency, range, and sanity check.
Concrete prompt
Estimate annual rides in a city. This tests population base, participation, frequency, time conversion, units, and scale sanity checks.
Choose the next drill
If units failed, run unit drills. If assumptions were weak, run assumption practice. The diagnostic should produce one clear next action.
Common mistakes
Candidates often treat a bad final number as the whole diagnosis. The broken step matters more than the final miss because it determines the repair drill.
Practice the pattern
Use the LeetQuidity curriculum and calibration to turn this topic into a focused practice plan.