Laws of Software Engineering · Saying
Saying
The McNamara Fallacy
What can be measured easily gets attention. What cannot gets ignored. Eventually the unmeasured is declared unimportant.
How to use it. When a team is "data-driven", check what they are not measuring. Cognitive load, trust, judgement, and taste have no clean metrics. All of them matter.
How it gets misused. Used as an excuse to avoid measurement entirely. McNamara's mistake was treating the measurable as the only real. The fix is to keep measuring carefully and to mark explicitly what you are not measuring.
Related
- Saying Gilb's Law Anything you need to measure can be measured in some way that is better than not measuring it at all.
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Pattern
Goodhart's Law
Once a measurement becomes a target, it stops being a useful measurement.
Clusters
- The Measurement cluster - How to measure without breaking the things you measure.