Why does anomaly detection signals fail?

The most common reason anomaly detection signals fails: Treating each anomaly as an isolated incident and explaining it away with a local excuse. One miss is noise. Two misses in the same domain are a pattern. Three are a signal you are actively ignoring. The most common failure is rationalizing each exception individually so you never see the cluster.

The fix: Open your journal, task manager, or notes from the past two weeks. Look for three instances where reality surprised you — a prediction that missed, a conversation that went sideways, a decision that produced unexpected results. Write each on its own line. Now ask: do these point to the same underlying schema that needs revision? If two or more cluster around a single assumption, you have found your evolution signal.

The underlying principle is straightforward: When reality repeatedly contradicts your schema the schema needs updating.