The Association for the Advancement of Artifcial Intelligence, in cooperation with Stanford University's Department of Computer Science, presented the 2018 Spring Symposium Series, held March 26-28, 2018, on the campus of Stanford University. The seven symposia held were AI and Society: Ethics, Safety, and Trustworthiness in Intelligent Agents; Artifcial Intelligence for the Internet of Everything; Beyond Machine Intelligence: Understanding Cognitive Bias and Humanity for WellBeing AI; Data-Effcient Reinforcement Learning; The Design of the User Experience for Artifcial Intelligence (the UX of AI); Integrated Representation, Reasoning, Learning, and Execution for Goal-Directed Autonomy; Learning, Inference, and Control of Multiagent Systems. This report, compiled from organizers of the symposia, summarizes the research of the symposia that took place.