MEPX
Chapter 7 of 10All chapters
  1. 1What is one row
  2. 2Rates and denominators
  3. 3Beyond the average
  4. 4Compared with what
  5. 5Aggregation traps
  6. 6Noise and significance
  7. 7Metrics and proxies
  8. 8Missing data
  9. 9Reading forecasts
  10. 10A reading routine

Chapter 7 of 10

Metrics and proxies

What is actually being measured.

Proxies drift

Every metric stands for something harder to measure. Optimising the proxy reliably produces the proxy, and the gap between it and the real goal widens over time.

  • Support tickets closed measures closing, not helping.
  • Pair a volume metric with a quality one to keep it honest.

Definitions

Active user, conversion and churn all have several defensible definitions. Comparing figures across teams or reports without checking the definition produces confident nonsense.