CONTRAST: Computing Tradeoffs among Normative Multiagent System Specifications

We propose CONTRAST, a formal framework for comparing normative multiagent system (nMAS) specifications by computing tradeoffs among liveness (something good happens) and safety (nothing bad happens). Safety-focused specifications restrict agents’ actions to avoid undesired executions. However, such restrictions hinder liveness, particularly in situations such as medical emergencies. Moreover, tradeoffs arise due to limited resources or inherent contradictions. We formalize such tradeoffs using norms, and develop an approach for understanding how much a specification promotes liveness or safety. We propose normative patterns to guide the design of an nMAS with respect to liveness and safety. We propose metrics to measure liveness and safety, and perform experiments on an emergency healthcare scenario using constraint logic programming.