Coaching practices for Fermi Estimation at Work

Describe almost anything you are working through and IX Coach finds the practices whose real-world fit is closest. For Fermi Estimation at Work, these are the strongest matches in the current practice library.

Does this sound like the set of challenges you might be facing?

  • My guesses never seem to get any better because I make them, find out the real answer, and then just move on
  • I land on a number and just go with it, never pausing to ask what’s the most it could possibly be or the least
  • I tend to blurt out one confident-sounding number and act like it’s solid, when honestly I have no business being that sure
  • My answer came out wildly off and I can feel that it’s wrong but can’t spot where
  • I’m staring at a question that feels totally out of reach, and it never occurs to me that I already know one solid number nearby that I could just scale up or down from

Practices that may help

  1. Fermi Estimation
    Fermi estimation is the practice of making rough but principled quantitative estimates by decomposing an unknown into knowable sub-problems, estimating each, and combining them. Named for physicist Enrico Fermi, who was renowned for accurate estimates from minimal data, it is used in science, engineering, and everyday decisions to calibrate intuitions and check whether a number is in the right ballpark — not to achieve false precision.
  2. Track your estimates and calibrate
    Compare your Fermi estimates to actual figures when you can, and use the gap to improve future estimates.
    Fermi Estimation
  3. Sanity-check against known extremes
    Test your estimate against the clearly too-high and too-low bounds to calibrate your range.
    Fermi Estimation
  4. Estimate in ranges, not point estimates
    Instead of "my estimate is 500," say "I think it is between 200 and 2000."
    Fermi Estimation
  5. Check units and scales for consistency
    Catch order-of-magnitude errors by ensuring your units are consistent across the estimate.
    Fermi Estimation
  6. Anchor on what you know and scale from there
    Start from a number you are confident about, then reason to the unknown.
    Fermi Estimation
  7. Decompose the unknown into knowable sub-problems
    Break the question you cannot answer directly into smaller questions you can.
    Fermi Estimation
  8. Practice confidence interval estimation
    Estimate ranges for factual quantities and check how often the true value falls within your range.
    Calibration Training
  9. Decompose complex questions into sub-questions
    Break a hard forecasting question into smaller, estimable pieces and aggregate them.
    Superforecasting
  10. Forecast a distribution, not a point estimate
    Represent your forecast as a range of likely outcomes, not a single predicted number.
    Reference Class Forecasting

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