Modelling Uncertainty in 3APL

Acknowledgements I would like to thank my supervising committee and fellow students, both at the artificial intelligence-thesis group at the Open Universiteit, and my collegue-thesis students in 'room 142' in Utrecht, for their support, thoughtful critique and interest. I owe especially much to Schil de Vos and Mehdi Dastani. Schil, having supervised tens of students at the Open Universiteit, knows probably better than anyone else out there what it takes to combine thesis research, a job and a family. As a mentor, Schil did his best to guide me through the bureaucracy an university sometimes can be. Mehdi was more than 'just' a daily supervisor. He learned me the tricks of the trade of writing an academic paper, showed genuine interest in my work and greatly stimulated me to pursue an academic career. I hope we have ample opportunity to continue working together. Some people greatly influenced my research interests, most probably without knowing. Although I hesitate to list such great and renowned researchers in this thesis, I feel I owe credit to Luc Steels, whose book 'Kennissystemen' first introduced me to Artificial Intelligence; Paul Churchland, Jerry Fodor and John Searle, whose disputes helped me to form my own opinion on Artificial Intelligence and how it is to be accomplished, and Arthur C. Clarke and Stanley Kubrick (and of course HAL) for inspiration and imagination. Last, but certainly not least, I thank Judith for her love and caring. Hopefully I have some more spare time now to spend together.