Contributors and acknowledgements
The people @ Pisa KDD Lab: Francesco BONCHI, Giuseppe MANCO, Mirco NANNI, Chiara RENSO, Salvatore RUGGIERI, Franco TURINI and many students

The many KDD tutorialists and teachers which made their slides available on the web (all of them listed in bibliography) ;-)
In particular:
Jiawei HAN, Simon Fraser University, whose forthcoming book Data mining: concepts and techniques has influenced the whole tutorial
Rajeev RASTOGI and Kyuseok SHIM, Lucent Bell Labs
Daniel A. KEIM, University of Halle
Daniel Silver, CogNova Technologies

The EDBT2000 board who accepted our tutorial proposal