---
title: Drift Detector
slug: drift-detector
url: https://templeton.host/lexicon/drift-detector/
type: defined-term
inDefinedTermSet: https://templeton.host/lexicon
author: Andrew Templeton
---

# Drift Detector

## Definition

A posterior predictive check that detects when the operator's preferences have drifted from the learned model. Computed as the fraction of recent decisions the model predicted incorrectly. When the drift score exceeds a threshold, the agent triggers re-elicitation.

## Why this term exists

Preferences are not static. People change their minds, priorities shift, new constraints emerge. The drift detector is how the agent notices that the operator changed their mind - and responds proportionally.

## See also

- [The Deity Problem](https://templeton.host/frameworks/deity-problem)
- [Autonomy State Machine](https://templeton.host/lexicon/autonomy-state-machine)
- [Structured Elicitation](https://templeton.host/lexicon/structured-elicitation)

Canonical URL: https://templeton.host/lexicon/drift-detector/