Principles of Data Mining and Knowledge Discovery : 4th European Conference PKDD 2000 Lyon France September 13–16 2000 Proceedings This book constitutes the refereed proceedings of the 4th European Conference on Principles and Practice of Knowledge Discovery in Databases PKDD 2000 held in Lyon France in September 2000. The 86 revised papers included in the book correspond to the 29 oral presentations and 57 posters presented at the conference. They were carefully reviewed and selected from 147 submissions. The book offers topical sections on new directions rules and trees databases and reward based learning classification association rules and exceptions instance based discovery clustering and time series analysis