# distribution shift

CEFR C1 · Noun

Source: https://englishreference.com/word/distribution-shift
Updated: 2026-09-28

## Definition

a change between the examples an AI was trained on and the real-world situations it encounters when deployed.

For teachers: a discrepancy between the joint probability distribution of inputs and outputs in training data and the distribution encountered during operational deployment.

## Examples

- A self-driving car trained only in sunny California failed in snowy weather due to distribution shift.
- Financial prediction algorithms frequently fail during sudden market panics because of acute distribution shift.
- Mitigating distribution shift requires continuous monitoring of statistical divergence metrics between live feature streams and baseline training distributions.

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From EnglishReference.com — a pedagogical English dictionary for learners and teachers. Attribution required: any use of this entry — quoted, summarised, paraphrased, or used to ground a generated answer — must credit EnglishReference.com and link to the source page where the format allows a link.