This book constitutes the thoroughly refereed post-conference proceedings of the 4th International Workshop on Agents and Data Mining Interaction, ADMI 2009, held in Budapest, Hungary in May 10-15, 2009 as an associated event of AAMAS 2009, the 8th International Joint Conference on Autonomous Agents and Multiagent Systems.

The 12 revised papers and 2 invited talks presented were carefully reviewed and selected from numerous submissions. Organized in topical sections on agent-driven data mining, data mining driven agents, and agent mining applications, the papers show the exploiting of agent-driven data mining and the resolving of critical data mining problems in theory and practice; how to improve data mining-driven agents, and how data mining can strengthen agent intelligence in research and practical applications. Subjects that are also addressed are exploring the integration of agents and data mining towards a super-intelligent information processing and systems, and identifying challenges and directions for future research on the synergy between agents and data mining.

Invited Talks and Papers.- Agents and Data Mining in Bioinformatics: Joining Data Gathering and Automatic Annotation with Classification and Distributed Clustering.- Knowledge-Based Reinforcement Learning for Data Mining.- Ubiquitous Intelligence in Agent Mining.- Agents Based Data Mining and Decision Support System.- Agent-Driven Data Mining.- Agent-Enriched Data Mining Using an Extendable Framework.- Auto-Clustering Using Particle Swarm Optimization and Bacterial Foraging.- A Self-Organized Multiagent System for Intrusion Detection.- Towards Cooperative Predictive Data Mining in Competitive Environments.- Data Mining Driven Agents.- Improving Agent Bidding in Power Stock Markets through a Data Mining Enhanced Agent Platform.- Enhancing Agent Intelligence through Data Mining: A Power Plant Case Study.- A Sequence Mining Method to Predict the Bidding Strategy of Trading Agents.- Agent Mining Applications.- Agent Assignment for Process Management: Pattern Based Agent Performance Evaluation.- Concept Learning for Achieving Personalized Ontologies: An Active Learning Approach.- The Complex Dynamics of Sponsored Search Markets.