Development and implementation of techniques for ontology engineering and an ontology-based search for bioinformatics tools and methods

(Indra Mainz) "Everything should be made as simple as possible–but no simpler!"-Albert Einstein Meinen Eltern. Acknowledgements First of all I would like to thank my supervisor apl. Prof. Dr. Gerhard Steger for the freedom in doing research and the confidence he had shown me. Thank you, Gerhard, for facing the world of ontologies. Additionally, I wish to thank Prof. Dr. Martin Lercher for accepting the task to read this thesis as a second reviewer. Special thanks are addressed to my colleagues Dominic, Ingo and Katrin for always fruitful and constructive discussions and a close collaboration. Additional thanks to all other ONTOVERSE project partners. Furthermore, I like to thank all my colleagues in the Institute of Biophysics for a great atmosphere , especially the bioinformatics guys and Natalie. I had a great time. Of course I whish to thank my dear family and friends just for being you. Becci & Jeremia, Domi, Nahal, Evgin and Timo, this is for you. Special thanks to Deniz, who read and challenged this thesis and beared me in good and bad times. I am very grateful to my parents for paving this way for me and supporting me all the time. You are wonderful! Financial support from the German Federal Ministry of Education and Research is gratefully acknowledged.