diff --git a/README.md b/README.md index b1bdcf3..8dc2f72 100644 --- a/README.md +++ b/README.md @@ -42,6 +42,7 @@ Like this project? Please considering [Sponsoring Me](https://github.com/sponsor * [The Spotify Model](#the-spotify-model) * [Wadler's Law](#wadlers-law) * [Wheaton's Law](#wheatons-law) + * [Goodhart's Law](#goodharts-law) * [Principles](#principles) * [The Dilbert Principle](#the-dilbert-principle) * [The Pareto Principle (The 80/20 Rule)](#the-pareto-principle-the-8020-rule) @@ -423,6 +424,30 @@ See also: Coined by Wil Wheaton (Star Trek: The Next Generation, The Big Bang Theory), this simple, concise, and powerful law aims for an increase in harmony and respect within a professional organization. It can be applied when speaking with coworkers, performing code reviews, countering other points of view, critiquing, and in general, most professional interactions humans have with each other. +### Goodhart's Law + +[The Goodhart's Law on Wikipedia](https://en.wikipedia.org/wiki/Goodhart's_law) + +> Any observed statistical regularity will tend to collapse once pressure is placed upon it for control purposes. +> +> _Charles Goodhart_ + +also known as: + +> When a measure becomes a target, it ceases to be a good measure. +> +> _Marilyn Strathern_ + +The law states that the measure-driven optimizations could lead to devaluation of the measurement outcome itself. Overly selective set of measures ([KPIs](https://en.wikipedia.org/wiki/Performance_indicator)) blindly applied to a process results in distorted effect. People tend to optimize locally by "gaming" the system in order to satisfy particular metrics instead of paying attention to hollistic outcome of their actions. + +Real-world examples: +- Assert-free tests satisfy the code coverage expectation, despite the metric intent was to create well-tested software. +- Developer performance score indicated by the number of lines committed leads to unjustifiably bloated codebase. + +See also: +- [Goodhart’s Law: How Measuring The Wrong Things Drive Immoral Behaviour](https://coffeeandjunk.com/goodharts-campbells-law/) +- [Dilbert on bug-free software](https://dilbert.com/strip/1995-11-13) + ## Principles Principles are generally more likely to be guidelines relating to design.