In the field of artificial intelligence applied to materials science, a fundamental conflation persists in which exploration noise and scientific error are routinely conflated as interchangeable “mistakes” that must be minimized or eliminated to improve model performance. This paper proposes precise conceptual definitions that separate exploration noise—understood as stochastic variation deliberately or unavoidably introduced into decision-making processes to probe uncertain regions of materials design space—from scientific error, defined as any deviation from ground truth that reduces predictive fidelity, distorts mechanistic understanding, or precipitates incorrect materials decisions without any compensating epistemic gain. The distinction matters profoundly because the systematic elimination of exploration noise eradicates the very mechanism that drives discovery in high-dimensional, data-scarce materials landscapes. In contrast, misclassifying scientific error as mere noise allows systematic flaws to propagate undetected through autonomous discovery pipelines. To resolve this ambiguity, the present work offers a four-criterion framework grounded in intentionality, epistemic benefit, systematicity, and correctability that enables researchers to classify any observed deviation with conceptual clarity. Adoption of this framework carries immediate implications for materials AI practice: it demands new reporting standards that explicitly quantify and justify exploration noise, revised peer-review criteria that interrogate rather than penalize productive randomness, and a cultural shift that reframes stochasticity not as a defect to be denoised but as an essential epistemic resource for accelerating the discovery of novel materials with targeted functionalities.