<story><title>Goodhart&apos;s Law</title><url>https://en.wikipedia.org/wiki/Goodhart%27s_law</url></story><parent_chain></parent_chain><comment><author>rpdillon</author><text>A closely-related effect I often cite is the McNamara fallacy[0], which is essentially about the tendency to focus on aspects of a system that are easily measurable, often at the expense of aspects that are not.  I see it as one of the weaknesses of the data-driven decision-making movement, since many interpret &amp;quot;data&amp;quot; to mean &amp;quot;numbers&amp;quot;.  I think this fallacy can partly explain why Goodhart&amp;#x27;s Law holds: it&amp;#x27;s the non-measurable (or difficult-to-measure) aspects that suffer most when a metric becomes a target, since measurable aspects could be (and often are) integrated into the target metric.&lt;p&gt;[0]: &lt;a href=&quot;https:&amp;#x2F;&amp;#x2F;en.wikipedia.org&amp;#x2F;wiki&amp;#x2F;McNamara_fallacy&quot; rel=&quot;nofollow&quot;&gt;https:&amp;#x2F;&amp;#x2F;en.wikipedia.org&amp;#x2F;wiki&amp;#x2F;McNamara_fallacy&lt;/a&gt;</text></comment>
<story><title>Goodhart&apos;s Law</title><url>https://en.wikipedia.org/wiki/Goodhart%27s_law</url></story><parent_chain></parent_chain><comment><author>baron_harkonnen</author><text>I once mentioned Goodhart&amp;#x27;s Law to a data scientist at a company and they immediately rejected it based on the unironic assertion that&lt;p&gt;&amp;quot;that would mean that KPIs shouldn&amp;#x27;t be the sole measure of our performance that that doesn&amp;#x27;t make sense!&amp;quot;&lt;p&gt;My experience in the field has been that an astounding number of products have been destroyed and users harmed by failing to heed Goodhart&amp;#x27;s Law.</text></comment>