RS Glossary
Model Drift
Model drift is a decline or change in a model's real-world performance because the data, behavior, relationships, or conditions it encounters no longer match those under which it was developed and evaluated.
- Review state
- Needs review
- Freshness
- Current
- Version
- 2
- Model Drift
Remember it this wayThe model stayed; the world moved.
In plain language
The model may be unchanged while the world around it moves. New customer behavior, fraud patterns, language, equipment, policies, or workflows can make earlier patterns less useful.
Why it matters
A model that passed its original tests can become unreliable after deployment. Monitoring and rereview must be tied to changing conditions, not only elapsed time.
Example
A fraud model trained before a new payment method is introduced begins missing scams that use the new channel.
Common misconception
Model drift is not simply a software bug or a model changing its own weights. The mismatch can arise because the environment changed.
Related terms
Sources
- NIST, *Challenges to the Monitoring of Deployed AI Systems* (NIST AI 800-4)current report on post-deployment monitoring, performance degradation, distribution shift, and drift.
- NIST, *Artificial Intelligence Risk Management Framework 1.0*explains that changing data can affect deployed system functionality and trustworthiness.
Learn more
- Compare system assumptions with [[context-to-reality-drift|Context-to-Reality Drift]].
Public history
36 recorded events · 36 public summaries
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definition approved by a human reviewer.
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why-it-matters approved by a human reviewer.
example approved by a human reviewer.
common-misconception approved by a human reviewer.
remember-it-this-way approved by a human reviewer.
related-terms approved by a human reviewer.
sources returned for revision.
learn-more approved by a human reviewer.
Requested wording was prepared without changing approved or existing sections.
Radar reviewed the pending sources section for human consideration.
Radar must rereview the complete model-drift term after an accepted text change.
Radar must rereview the complete model-drift term after an accepted text change.
Radar must rereview the complete model-drift term after an accepted text change.
Radar must rereview the complete model-drift term after an accepted text change.
Radar must rereview the complete model-drift term after an accepted text change.
Radar must rereview the complete model-drift term after an accepted text change.
Radar must rereview the complete model-drift term after an accepted text change.
Radar must rereview the complete model-drift term after an accepted text change.
Radar must rereview the complete model-drift term after an accepted text change.
sources approved by a human reviewer.
sources approved wording became the current section text.
All section gates are approved; content version 2 is now a fully approved term.
Source: vault/Glossary/terms/model-drift/term.md · sha256:434d6956cd99b12c531ee875d50539ed35a42902f8c5f8a1d0ad8ead3fe6c029 · Release: rs-glossary-glossary-team-poc-0.5.5-2026-09-02