Search

Materials machine learning has achieved remarkable success in building accurate predictive models for properties such as formation energy, band gap, and mechanical strength. Yet the ultimate purpose of the field is not prediction but design: the discovery of new materials that deliver target properties under real-world constraints. This perspective argues that the community must shift from prediction-centric to optimization-centric workflows. Prediction-centric approaches focus on minimizing mean absolute error on randomly held-out test sets, while optimization-centric workflows aim to maximize (or minimize) a target property value within practical budgets, constraints, and sequential decision-making. These are fundamentally different objectives that demand different methods, evaluation metrics, and research priorities. A prediction-centric model may achieve low error on interpolation tasks yet fail catastrophically when asked to guide the search for extreme or out-of-distribution materials. In contrast, optimization-centric workflows treat the machine-learning model as a surrogate within an iterative loop that actively selects the next experiment or simulation. Four core principles underpin this shift: explicit goal specification that includes both the objective and all relevant constraints; robust constraint handling that distinguishes hard feasibility requirements from soft trade-offs; uncertainty awareness, where every prediction is accompanied by well-calibrated uncertainty estimates essential for balancing exploration and exploitation; and closed-loop integration that connects the model directly to automated or high-throughput experimentation and simulation. Adopting these principles will require new evaluation protocols that measure the best material discovered, sample efficiency, regret, constraint satisfaction, and extrapolation distance rather than isolated accuracy metrics. The implications extend to model development, benchmark design, journal standards, and funding priorities. Only by embracing optimization-centric workflows can materials machine learning fulfill its promise of accelerating discovery and delivering materials that solve pressing societal challenges.

In the evolving landscape of computational and data-driven materials engineering, the integration of machine learning and high-throughput methodologies has accelerated discovery processes, yet it introduces a paradox where rapid optimization often bypasses deep scientific understanding. This manuscript presents a systems theory perspective on black-box optimization in autonomous materials engineering, emphasizing closed-loop labs where AI-driven decisions guide experimentation without explicit interpretability. Drawing from materials informatics and representation learning, we identify the discovery acceleration paradox: enhanced efficiency in inverse design and property prediction erodes traditional epistemic structures, leading to reliance on opaque models. We introduce the "Epistemic Opaque Discovery System" (EODS) framework, which conceptualizes materials discovery as a layered network of data infrastructures, model architectures, and feedback mechanisms. This framework highlights trade-offs between optimization speed and interpretability, incorporating uncertainty quantification to mitigate risks in autonomous systems. Implications extend to simulation-experiment coupling and multimodal datasets, suggesting pathways for balanced computational workflows that preserve scientific insight amid black-box dominance. By reframing discovery pipelines, EODS offers a theoretical lens for engineering resilient AI ecosystems in materials science, fostering sustainable innovation without sacrificing foundational knowledge.

In the evolving landscape of computational and data-driven materials engineering, machine learning techniques have revolutionized the discovery and optimization of materials by leveraging vast datasets to identify patterns and correlations. However, this reliance on correlation-driven approaches often overlooks the underlying causal mechanisms that govern material properties and behaviors, leading to inherent limitations in the generalizability and robustness of designed materials. This manuscript explores the conceptual boundaries of optimization strategies that prioritize statistical associations over causal understanding within materials informatics ecosystems. We introduce a novel conceptual framework, termed the Correlation Boundary Architecture (CBA), which delineates the epistemic constraints imposed by correlation-centric pipelines in materials design. The CBA integrates representation learning, inference dynamics, and feedback structures to highlight how data-driven optimizations can falter in extrapolative scenarios, such as novel chemical spaces or extreme conditions. By synthesizing recent advancements in graph neural networks, high-throughput computations, and uncertainty quantification, we articulate the trade-offs between computational efficiency and causal fidelity. Implications extend to autonomous discovery systems and inverse design paradigms, suggesting pathways for hybrid frameworks that mitigate correlation biases through enhanced interpretive layers. This work underscores the need for computational steering logics that balance correlative power with causal awareness, fostering more resilient materials engineering practices.