This volume presents the proceedings of the 9th European Knowledge Acquisition Workshop. The 23 revised full papers included address theoretical and applicational aspects of knowledge acquisition with a certain emphasis on the modelling or automation of complex problem-solving behaviour.

Assumptions of problem-solving methods.- Problem-solving methods: Making assumptions for efficiency reasons.- The thin end of the wedge: Efficiency and the generalised directive model methodology.- Principles for libraries of task decomposition methods — Conclusions from a case-study.- A purpose driven method for language comparison.- A conceptual and formal model of a diagnostic reasoner.- Ontology construction for technical domains.- Text clustering to help knowledge acquisition from documents.- A quality-based terminological reasoning model for text knowledge acquisition.- Extracting conceptual knowledge from text using explicit relation markers.- Structuring information in a distributed hypermedia system.- Diagrammatic knowledge acquisition: Elicitation, analysis and issues.- An approach to measuring theory quality.- Some late-breaking news from the data mines and a preview of the KOALA system: A prospector's report.- A knowledge acquisition tool for multi-perspective concept formation.- Knowledge discovery in databases: Exploiting knowledge-level redescription.- Towards painless knowledge acquisition.- The acquisition of a shared task model.- The group elicitation method: An introduction.- Formalising the repair of schedules through knowledge acquisition.- Intelligent tools for planning knowledge base development and verification.- Configuring service recovery planning with the CommonKADS library.- Domain and system influences in problem solving models for planning.