In conjunction with the 6 Preface

Interacting with a recommender system means to take different decisions such as selecting a song/movie from a recommendation list, selecting specific feature values (e.g., camera’s size, zoom) as criteria, selecting feedback features to be critiqued in a critiquing based recommendation session, or selecting a repair proposal for inconsistent user preferences when interacting with a knowledge-based recommender. In all these scenarios, users have to solve a decision task.

The complexity of decision tasks, limited cognitive resources of users, and the tendency to keep the overall decision effort as low as possible lead to the phenomenon of bounded rationality, i.e., users exploit decision heuristics rather than trying to take an optimal decision. Furthermore, preferences of users will likely change throughout a recommendation session, i.e., preferences are constructed in a specific decision environment and users do not know their preferences beforehand.

Decision making under bounded rationality is a door opener for different types of non-conscious influences on the decision behavior of a user. Theories from decision psychology and cognitive psychology are trying to explain these influences, for example, decoy effects and defaults can trigger significant shifts in item selection probabilities; in group decision scenarios, the visibility of the preferences of other group members can have a significant impact on the final group decision.

The major goal of this workshop was to establish a platform for industry and academia to present and discuss new ideas and research results that are related to the topic of human decision making in recommender systems. The workshop consisted of technical sessions in which results of ongoing research as reported in these proceedings were presented, a keynote talk given by Joseph A. Konstan on “Decision-Making and Recommender Systems: Failures, Successes, and Research Directions” and a wrap up session chaired by Alexander Felfernig.

Marco de Gemmis, Alexander Felfernig, Pasquale Lops, Francesco Ricci, Giovanni Semeraro and Martijn Willemsen

September 2012

 Workshop Committee Workshop Co-Chairs Marco de Gemmis, University of Bari Aldo Moro, Italy Alexander Felfernig, Graz University of Technology, Austria Pasquale Lops, University of Bari Aldo Moro, Italy Francesco Ricci, University of Bozen‐Bolzano, Italy Giovanni Semeraro, University of Bari Aldo Moro, Italy Martijn Willemsen, Eindhoven University of Technology, Netherlands Organization Monika Mandl, Graz University of Technology Gerald Ninaus, Graz University of Technology Program Committee Robin Burke, DePaul University, USA Li Chen, Hong Kong Baptist University, China Marco De Gemmis, University of Bari Aldo Moro, Italy Benedict Dellaert, Erasmus University Rotterdam, Netherlands Alexander Felfernig, Graz University of Technology, Austria Gerhard Friedrich, University of Klagenfurt, Austria Sergiu Gordea, Austrian Institute for Technology, Austria Andreas Holzinger, Medical University Graz, Austria Dietmar Jannach, University of Dortmund, Germany Bart Knijnenburg, University of California, USA Alfred Kobsa, University of California, USA Gerhard Leitner, University of Klagenfurt, Austria Pasquale Lops, University of Bari Aldo Moro, Italy Walid Maalej, Technische Universität München, Germany Monika Mandl, Graz University of Technology, Austria Alexandros Nanopoulos, University of Hildesheim, Germany Francesco Ricci, University of Bolzano, Italy Olga C. Santos, UNED, Spain Giovanni Semeraro, University of Bari Aldo Moro, Italy Erich Teppan, University of Klagenfurt, Austria Marc Torrens, Strands, Spain Martijn Willemsen, Eindhoven University of Technology, Netherlands Markus Zanker, University of Klagenfurt, Austria

Decision-Making in Recommender Systems: The Role of User’s Goals and Bounded Resources P. Cremonesi, A. Donatacci, F. Garzotto, R. Turrin 1 Enhancement of the Neutrality in Recommendation T. Kamishima, S. Akaho, H. Asoh, J. Sakuma The Effect of Sensitivity Analysis on the Usage of Recommender Systems M. Maida, K. Maier, N. Obwegeser, V. Stix Recommending Personalized Query Revisions H. Blanco, F. Ricci, D. Bridge Eliciting Stakeholder Preferences for Requirements Prioritization A. Felfernig, G. Ninaus, F. Reinfrank Recommendation Systems in the Scope of Opinion Formation: a Model M. Blattner, M. Medo Effects of Online Recommendations on Consumers' Willingness to Pay G. Adomavicius, J. Bockstedt, S. Curley, J. Zhang Copyright © 2012 for the individual papers by the papers' authors. Copying permitted for private and academic purposes. This volume is published and copyrighted by its editors. 8 15 19 27 32