# perturbation

/ˌpɝtɝˈbeɪʃən/ (US) · /pətəbˈeɪʃən/ (UK) · CEFR C1 · Noun

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

## Definition

a small, intentional change made to an input, system, or setting to see how it responds.

For teachers: a minor deviation, disturbance, or deliberate modification applied to input data, weights, or activations to evaluate system sensitivity, robustness, or causality.

## Examples

- Adding subtle digital noise to the image was a perturbation designed to test the camera sensor.
- Adversarial attacks introduce an imperceptible pixel perturbation that tricks the image model into misclassification.
- Activation patching applies targeted representation perturbation at runtime to determine the causal role of individual layers in factual recall tasks.

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