I would like to express my deep gratitude to Dr. Chiara Renso, Professor Valeria Times, and Professor Rossano Venturini, my research supervisors, for their patient guidance, enthusiastic encouragement and useful critiques of this research work. Their guidance helped me constantly during the time spent in research and writing this thesis. Without doubt, I had the luck to have a really great team of supervisors. I would also like to thank Dr. Raffaele Perego, for his valuable advice and the opportunity to undertake my Ph.D. research within the HPC lab of ISTI-CNR Pisa. It was fantastic to have the opportunity to work in his facilities. My grateful thanks are also extended to Professor Iadh Ounis and Professor Craig McDonald, from the University of Glasgow, for their collaboration in building the predictive models for user attendance using Social Media, and to Dr. Salvo Rinzivillo, from the KDD Lab ISTI-CNR Pisa, who helped me elaborate our novel ride-sharing matching algorithm. I would also like to extend my thanks to my colleagues of the HPC Lab for the fun and support. The years spent at the HPC Lab were anything but sharing deadlines, hard work, events and travels with such special people. Certainly, all these experiences shared with them made this achievement less hard to be earned. In particular, I would like to individually thank Dr. Patrizio Dazzi, Dr. Massimo Coppola and Dr. Emanuele Carlini for the opportunity to participate in the BASMATI Project developing my skills as researcher. Moreover, thanks to the external reviewers, Professor Stan Matwin and Professor Yannis Theodoridis, for taking the effort to contribute to this work by reviewing it: I am really honored of having their endorsement. I am also grateful to the UNIPI committee members Professor Anna Monreale and Professor Roberto Grossi for their priceless comments and suggestions to improve my Ph.D. research. I am especially grateful to my parents for their unconditional love and support in my life. I owe them all I am. I thank as well to all family, who supported me along the completion of the Ph.D. program. And finally, last but by no means least, I thank all my friends that somehow contributed to my growth during this period.