Séminaire MIDI : Dr Kostas Stefanidis

Titre du séminaire et orateur

On supporting Sequential Group Recommandations in Fairness"

Dr Kostas Stefanidis (Associate Professor at Tampere University)

Date et lieu

Mercredi 18 septembre 2019, 16h.

Université de Cergy-Pontoise, St Martin I, ETIS, salle 570


Recommender systems have been incorporated in our every day life; from music to health recommendations, recommender systems have enhance the user's experience. Additionally, with the expansion of the social media, group recommenders have become more popular. In this work, we claim that a recommendation query should not be a stand-alone process. A real world system, should require access to history logs, and take them into account when recommending items for a group of users. Not only what items the system previously had recommended, but also how well were these items received by the members of the group. Specifically, we propose a sequential group recommendation model, which is aware of the past interactions of the group with the system. We introduce the notion of satisfaction, that describes how relevant were the recommended items to each member, and utilize it in a novel aggregation method that targets at making our model fair for all members of the group.


Kostas Stefanidis is an Associate Professor on Data Science at the Faculty of Information Technology and Communication Sciences of the Tampere University, Finland. Prior to that, he was a research scientist with the Information Systems Lab of ICS-FORTH, Greece, and a postdoctoral researcher at the IDI Dept. of NTNU in Norway and the CSE Dept. of CUHK in Hong Kong. He got his PhD in personalized data management from the Univ. of Ioannina, Greece. His research interests are in the broader area of big data. They lie in the intersection of databases, information retrieval, data mining and the Web, and include personalization and recommender systems, large-scale entity resolution and information integration, and query and data exploration paradigms. He has been involved in several international research projects and co-authored more than 80 papers in peer-reviewed conferences and journals, including ACM SIGMOD, IEEE ICDE, EDBT and ACM TODS, Elsevier. He is also actively serving the scientific community. Currently, he is the General co-Chair of the Workshop on Semantic Web Technologies for Health Data Management, co-located with ISWC, and he served as the Web & Information Chair of SIGMOD/PODS 2016, the Proceedings Chair of EDBT/ICDT 2016, and the Registration Chair of CIKM 2018. He is the recipient of two best paper awards (ISWC 2015, PIC 2018), one Recognition of Service Award from ACM, and co-authored a book on Entity Resolution in the Web of Data.