\project thesis \startcomponent acknowledgements \startchapter [title={Acknowledgements}, reference=chap:acknowledgements] Foremost, I would like to thank my supervisors. Having three of them ensured that there was always enough ideas to work on, theory to understand, papers to review, seminars to attend, and chats to have. Frits, thank you for being a very motivating supervisor, pushing creativity, and being only a few meters away. It started with a small puzzle (trying whether a certain test algorithm would help a learning case study), which was a great, hands-on start of my PhD. You introduced me to the field of model learning in a way which showcases both the theoretical and practical aspects. Alexandra, thank you for inviting me to London, Caribbean islands, hidden cocktail clubs, and the best food. You introduced me to abstract reasoning about state machines, the coalgebraic way. Although not directly shown in this thesis, this way of thinking has helped and you pushed me to pursuit clear reasoning. Besides the theoretical things I've learned, you've also taught me many personal lessons inside and outside of academia. And thanks for leaving me with Daniela and Matteo, when you went on sabbatical. They have introduced me to nominal techniques, which I found a lot of fun. Bas, thanks for broadening my understanding of the topics touched upon in this thesis. Unfortunately, we have no papers together, but the connections you showed to logic, computational learning, and computability theory have influenced the thesis nevertheless. I am grateful for the many nice chats we had. At the first floor of the Mercator building, I had the pleasure of spending four years with fun office mates. Michele, thanks for introducing me to the Ph.D. life, by always joking around. Hopefully, we can play a game of Briscola again. Alexis, many thanks for all the tasty {\it\nl proeverijen,\en} wheter it was beers, wines, {\nl poffertjes, kroketten\en}, or anything else. Your French influences will be missed. Niels, thanks for the abstract nonsense and bashing on politics. Next to our office, was the office with Tim, with whom I had the pleasure of working from various coffee houses in Nijmegen. Further down the corridor, there was the office of Paul and Rick. Paul, thanks for being the kindest colleague I've had and for inviting us to your musical endeavours. Rick, thanks for the algorithmic sparring, we had a great collaboration. Was there a more iconic duo on our floor? A good contender would be Petra and Ramon. Thanks for the fun we had with ioco, together with Jan. Nils, thanks for steering me towards probabilistic things and opening a door to Aachen. I am also very grateful for Jurriaan for bringing back some coalgebra and category theory to our floor, and hosting me in London. My other co-authors, Wouter, David, Bartek, Micha\l{}, and David, also deserve many credits for all the interesting discussion we had. Harco, thanks for the technical support. Special thanks go to Ingrid, for helping with the often-overlooked, but very important, administrative matters. Doing a Ph.D. would not be complete without a good amount of playing kicker, having {\nl borrels\en}, and eating cakes at the iCIS institute. Thanks to all of you, Markus, Bram, Marc, Sam, Bas, Joost, Dan, Giso, Baris, Simone, Manxia, Leon, Jacopo, Gabriel, Paulus, Marcos, Bas, and Henning. \footnote[random]{In no particular order. (I have randomised this list.)} Thanks to people I have met across the channel (which hopefully will remain part of the EU): Benni, Nath, Kareem, Rueben, Louis, Borja, Fred, Tobias, Paul, Gerco, and Carsten, \note[random] for the theoretical adventure, but also for joining me to {\it Phonox} and other parties in London. I am especially thankful to Matteo and Emanuela for hosting me many times and for Hillary and Justin for accommodating me for three months each. I had a lot of fun at the IPA events. I'm very thankful for Tim and Loek for organising these events. Special thanks to Nico and Priyanka for organising a Halloween social event with me. Also thanks to all the participants in the IPA events, you made it a lot of fun! My gratitude extends to all the people I have met at summer schools and conferences. I had a lot of fun learning about different cultures, languages, and different ways of doing research. Hope we meet again! I would also like to thanks other friends, for hosting me, cooking excellent dinners, or otherwise having fun with me. Thanks, Gabe, Edo, Nick, Geert, Carmen, Marlon, Hannah, Wouter, Dennis, ??? Hash ru??? Familie Tessa \stopchapter \stopcomponent