Optimal Crossover Designs withInteractions between Treatments andUnitsDoctoral Thesisin fulfillment of the requirements for the degree of”Doktorin der Naturwissenschaften”submitted to the Faculty of Statisticsof the Technische Universit¨at DortmundbyAndrea M. BludowskyDortmund, July 30, 2009Referees: Prof. Dr. J. KunertProf. Dr. C. WeihsDate of oral examination: July 30, 2009AcknowledgmentsEventhoughtthisthesisjustbearsmyname,itwasaccomplishedbyalotofsupportof many people. My gratitude is for all the people that contributed:• First, thanks to Prof. Dr. J. Kunert. His support for a scholarship in the”Graduiertenkolleg Statistische Modellbildung” was the opportunity to earn adoctorate. Furthermore, he has given the inspiration for the topic of my thesisand assisted me with his academic advise.• Thanks to Prof. Dr. C. Weihs. He has provided me with necessary assistancefor clear and coherent proofs of my mathematical work.• I would like to thank Prof. Dr. G. Trenkler for taking the time in reading thethesis twice and helping me to improve my writing skills.• Thanks to my friends Vivien Rothe and Simone Wenzel for their motivatingtalks in times of throwbacks.• Special thanks are also given to my beloved husband, Thomas Bludowsky, forthe hours of taking a walk with our baby-daughter Emma. Thus, I had timeto concentrate on my work or to recover from many sleepless nights.