Acknowledgements

We would like to thank all our colleagues for feedback and comments, in particular Gerd Stumme for clarifying our FCA-related questions. We would also like to thank Johanna Völker for comments on a first version as well as for proof-reading the final version of the paper. All errors are of course our own. We would also like to acknowledge the reviewers of the Journal of Artificial Intelligence Research as well as the ones of the earlier workshops (ATEM04, FGML04) and conferences (LREC04, ECAI04) on which this work was presented for valuable comments. Philipp Cimiano is currently supported by the Dot.Kom project (http://www.dot-kom.org), sponsored by the EC as part of the framework V, (grant IST-2001-34038) as well as by the SmartWeb project (http://smartweb.dfki.de), funded by the German Ministry of Education and Research.