Multi-agent systems for education and interactive entertainment : design, use and experience ; [based on a selection of papers presented at the International Workshop on the Educational Uses of Multi-Agent Systems (EduMAS) which was held in conjunction with the International Workshop on Agent Based Systems for Human Learning and Entertainment (ABSHLE) at the Eighth International Conference on Autonomous Agents and Multi-Agent Systems (AAMAS) held in Budapest Hungary, in May 2009] (2011)