ParetoTracker: Understanding Population Dynamics in Multi-objective Evolutionary Algorithms through Visual Analytics
Zherui Zhang, Fan Yang, Ran Cheng, Yuxin Ma
TL;DR
ParetoTracker addresses the opacity of population dynamics in multi-objective evolutionary algorithms by delivering a visual analytics framework that integrates performance metrics, lineage tracking, and detailed operator views across generations. The approach uses an overview+detail design to enable multi-level analysis, from generation-level quality measures ($HV$, $IGD$, $SP$, $MS$) to per-generation operator descriptions and lineage connections. Through case studies (SMS-EMOA on DDMOP2 and NSGA-II on DTLZ3) and expert interviews, the paper demonstrates how integrated visualizations reveal convergence, diversity, and the nuanced roles of mutation and environmental selection in shaping the Pareto front. The framework promises practical utility for researchers and practitioners by facilitating pattern discovery, comparative analysis, and hypothesis generation across MOEAs, with avenues for scalability, generalization, and domain-specific extensions.
Abstract
Multi-objective evolutionary algorithms (MOEAs) have emerged as powerful tools for solving complex optimization problems characterized by multiple, often conflicting, objectives. While advancements have been made in computational efficiency as well as diversity and convergence of solutions, a critical challenge persists: the internal evolutionary mechanisms are opaque to human users. Drawing upon the successes of explainable AI in explaining complex algorithms and models, we argue that the need to understand the underlying evolutionary operators and population dynamics within MOEAs aligns well with a visual analytics paradigm. This paper introduces ParetoTracker, a visual analytics framework designed to support the comprehension and inspection of population dynamics in the evolutionary processes of MOEAs. Informed by preliminary literature review and expert interviews, the framework establishes a multi-level analysis scheme, which caters to user engagement and exploration ranging from examining overall trends in performance metrics to conducting fine-grained inspections of evolutionary operations. In contrast to conventional practices that require manual plotting of solutions for each generation, ParetoTracker facilitates the examination of temporal trends and dynamics across consecutive generations in an integrated visual interface. The effectiveness of the framework is demonstrated through case studies and expert interviews focused on widely adopted benchmark optimization problems.
