Sergio Duarte Torres' PhD defense last Friday February 14th resulted in a exceptional PhD degree cum laude. His PhD thesis: “Information Retrieval for Children: Search Behavior and Solutions” was written at the Database Group as part of the European project PuppyIR, a joint project with amongst others Human Media Interaction. Sergio's research shows an extraordinary diversity and heterogeneity, touching many areas of computer science, including Information Retrieval, Big Data analysis, and Machine Learning. Sergio sought cooperation with leading search engine companies in the field: Yahoo and Yandex. He did a three-month internship at Yahoo Research in Barcelona. Sergio's work is well-received. His paper on vertical selection for search for children was nominated for the Best Student Paper Award at the joint ACM/IEEE conference on Digital Libraries in Indianapolis, USA. His work is accepted at two important journals in the field: the ACM Transactions on the Web, and the Journal of the American Society of Information Science and Technology. Specifically worth mentioning is the user study with children aged 8 to 10 years old done by Sergio to evaluate the child-friendly search approaches that he developed. We are proud of the achievements of Sergio Duarte Torres. He will be an excellent ambassador of the University of Twente.