Human collective intelligence (HCI) and Artificial agent based models (ABM) have become popular in computational social system science literatures, however, until recently, there are very few opportunities for both social system scientists and computer scientists to meet together to discuss complex social decision problems such as city management, education, marketing, finance, and traffic systems. There exist so many stakeholders in social complex decision problems. To address the issues, it is indispensable to gather both social system scientists and computer scientists together. We must advance new theory and techniques to marriage HCI and ABMs. The workshop aims at providing a forum for discussions and presentations about these problems. For the purpose, we would like to focus on such cutting-edge technologies as collective intelligence and agent-based modeling to address these problems. The workshop is supported in part by JSPS KAKENHI Grant Number 25240048, Japan (Title: Study on Social Service Decisions through Participatory Simulation Mothodologies with Artificial Societies). The project will continue, at least, until 2016.