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https://ceur-ws.org/Vol-2948/preface.pdf
8th Joint Workshop on Interfaces and Human
Decision Making for Recommender Systems
(IntRS) 2021
Online Event, September 25th and September 29th, 2021
Proceedings
edited by Peter Brusilovsky
Marco de Gemmis
Alexander Felfernig
Elisabeth Lex
Pasquale Lops
Giovanni Semeraro
Martijn C. Willemsen
in conjunction with
15th ACM Conference on Recommender Systems (RecSys 2021)
Copyright © 2021 for the individual papers by the papers' authors. Copyright © 2021 for the volume as
a collection by its editors. This volume and its papers are published under the Creative Commons
License Attribution 4.0 International (CC BY 4.0).
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Preface
This volume contains the papers presented at the 8th Joint Workshop on Interfaces and Human Decision
Making for Recommender Systems (IntRS), held as part of the 15th ACM Conference on Recommender Systems
(RecSys), the premier international forum for the presentation of new research results, systems and techniques in
the broad field of recommender systems. The workshop was organized as a virtual event with the possibility to
arrange physical sessions at the venue of the main conference, Amsterdam. The workshop had a physical session
on September 29.
Recommender systems were originally developed as interactive intelligent systems that can proactively guide
users to items that match their preferences. Despite its origin on the crossroads of HCI and AI, the majority of
research on recommender systems gradually focused on objective accuracy criteria paying less and less attention
to how users interact with the system as well as the efficacy of interface designs from users’ perspectives. This
trend is reversing with the increased volume of research that looks beyond algorithms, into users’ interactions,
decision making processes, and overall experience.
The series of workshops on Interfaces and Human Decision Making for Recommender Systems focuses on
the “human side” of recommender systems. The goal of the research stream featured at the workshop is to
improve users’ overall experience with recommender systems by integrating different theories of human decision
making into the construction of recommender systems and exploring better interfaces for recommender systems.
The 8th Joint Workshop on Interfaces and Human Decision Making for Recommender Systems (IntRS'21)
takes a user-centric perspective on recommender systems research. The workshop highlights research
incorporating psychological theories and models and findings from HCI into the recommendation process.
It also studies interface-related aspects of recommender systems, i.e., how recommendations are presented to
the user and what kind of interactions are crucial to user satisfaction with the system as a whole. The IntRS’21
workshop brings together an interdisciplinary community of researchers and practitioners who share research on
novel (psychology-informed) recommender systems, including new design technologies and evaluation
methodologies, and who aim to identify critical challenges and emerging topics in the field.
The workshop covers three main research strands:
• User modeling and human decision making (e.g., cognitive, affective, and personality-based user
models for recommender systems, human-recommender interaction, decision biases, cognitive
biases, decision theory, preference construction, human memory theory, persuasive
recommendation and argumentation, cultural differences);
• User interfaces (e.g., visual interfaces, explanation interfaces, collaborative multi-user interfaces,
spoken and natural language interfaces, trust-aware and social interfaces, context-aware
interfaces, ubiquitous and mobile interfaces, example and demonstration-based interfaces, and
decision making);
• Evaluation (e.g., user-centric evaluation, novel evaluation metrics, case studies, benchmarking
platforms, empirical studies of new interfaces and interaction designs).
IntRS’21 follows successful workshops on the same topic organized at RecSys conferences in 2014 - 2020.
The workshop series was created by merging two original RecSys workshops series: Human Decision Making
and Recommender Systems (Decisions@RecSys – 2010–2013) and Interfaces for Recommender Systems
(InterfaceRS’12). The idea of merging the two workshops was motivated by the strong inter-relationship between
the user interface and human decision making topics. The combination of these two aspects seems to be highly
attractive. Earlier workshops, such as the IntRS’15 workshop in Vienna, the IntRS’16 in Boston, the IntRS’17 in
Como, the IntRS’18 in Vancouver, the IntRS’19 in Copenhagen and the IntRS'20 (virtual conference) had
attendance rates of over 50 participants.
The program includes an invited talk by Antony Jameson, Chusable AG, on Group Decision Making and
Group Recommender Systems, and 8 technical papers, that were selected among 10 submissions, through a
rigorous reviewing process, where each paper was reviewed by three PC members.
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The IntRS chairs would like to thank the RecSys 2021 workshop chairs, Jennifer Golbeck, Marijn Koolen,
and Denis Parra, for their guidance during the workshop organization. We also wish to thank all authors and all
presenters, and the members of the program committee. All of them secured the workshop’s high quality
standards.
September 2021
Peter Brusilovsky
Marco de Gemmis
Alexander Felfernig
Elisabeth Lex
Pasquale Lops
Giovanni Semeraro
Martijn C. Willemsen
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IntRS 2021 Workshop Organization
Chairs: Peter Brusilovsky, School of Information Sciences, University of Pittsburgh, USA
Marco de Gemmis, Dept. of Computer Science, University of Bari Aldo Moro, Italy
Alexander Felfernig, Institute for Software Technology, Graz University of
Technology, Austria
Elisabeth Lex, Institute of Interactive Systems and Data Science, Graz University of
Technology, Austria
Pasquale Lops, Dept. of Computer Science, University of Bari Aldo Moro, Italy
Giovanni Semeraro, Dept. of Computer Science, University of Bari Aldo Moro, Italy
Martijn C. Willemsen, Eindhoven University of Technology, The Netherlands
Proceedings Chairs: Marco de Gemmis, Dept. of Computer Science, University of Bari Aldo Moro, Italy
Pasquale Lops, Dept. of Computer Science, University of Bari Aldo Moro, Italy
Web Chair: Pasquale Lops, Dept. of Computer Science, University of Bari Aldo Moro, Italy
Program Committee: Ludovico Boratto, Eurecat, Spain
Robin Burke, University of Colorado Boulder, United States
Peter Dolog, Aalborg University, Denmark
Michael Ekstrand, Boise State University, United States
Sergiu Gordea, Austrian Institute of Technology, Austria
Denis Helic, Graz University of Technology, Austria
Andreas Holzinger, Medical University Graz and Graz Univ. of Technology, Austria
Dietmar Jannach, University of Klagenfurt, Austria
Julia Neidhardt, Vienna University of Technology, Austria
Marco Polignano, University of Bari Aldo Moro, Italy
Behnam Rahdari, University of Pittsburgh, United States
Olga C. Santos, National Distance Education University, Madrid, Spain
Alain Starke, Univ. of Bergen, Norway & Wageningen Univ. & Research, Netherlands
Luis Terán, University of Fribourg, Switzerland
Marko Tkalčič, University of Primorska, Slovevia
Chun-Hua Tsai, The Pennsylvania State University, United States
Wolfgang Wörndl, Technical University of Munich, Germany
Markus Zanker, Free University of Bozen-Bolzano, Italy
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Table of Contents
Invited Talk
Group Decision Making and Group Recommender Systems 1
Anthony Jameson
Long Papers
ConvEx-DS: A dataset for conversational explanations in recommender systems 3
Diana C. Hernandez-Bocanegra, Jürgen Ziegler
Mixed-Modality Interaction in Conversational Recommender Systems 21
Yuan Ma, Timm Kleemann, Jürgen Ziegler
How does the User’s Knowledge of the Recommender Influence their Behavior? 38
Muheeb Faizan Ghori, Arman Dehpanah, Jonathan Gemmell, Hamed Qahri-Saremi, Bamshad
Mobasher
Input or Output: Effects of Explanation Focus on the Perception of Explainable 55
Recommendation with Varying Level of Details
Mouadh Guesmi, Mohamed Amine Chatti, Laura Vorgerd, Shoeb Joarder, Qurat Ul Ain, Thao Ngo,
Shadi Zumor, Yiqi Sun, Fangzheng Ji, Arham Muslim
Evaluating Explainable Interfaces for a Knowledge Graph-Based Recommender 73
System
Erasmo Purificato, Baalakrishnan Aiyer Manikandan, Prasanth Vaidya Karanam, Mahantesh Vishvanath
Pattadkal, Ernesto William De Luca
Short Papers
Your eyes explain everything: exploring the use of eye tracking to provide explanations 89
on-the-fly
Martijn Millecamp, Toon Willemot, Katrien Verbert
The Immunity of Users’ Item Selection from Serial Position Effects in Multi-Attribute 101
Item Recommendation Scenarios
Thi Ngoc Trang Tran, Carmen Isabella Baumann, Alexander Felfernig, Viet Man Le
Controlling Personalized Recommendations in Two Dimensions with a Carousel-Based 112
Interface
Behnam Rahdari, Peter Brusilovsky, Alireza Javadian Sabet
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