WORKSHOP REPORT

Report on the 4th Workshop on
Context-awareness in Retrieval andRecommendation (CaRR 2014)
Alan SaidTU Delft
Delft, NL
alansaid@acm.org

Ernesto W. De Luca
FH-Potsdam
Potsdam, DE
deluca@fh-potsdam.deDaniele Quercia
Yahoo!
Barcelona, ES
dquercia@acm.org

October 2, 2014
Abstract
Context-aware information is widely available in various ways and is becoming more
and more important for enhancing retrieval performance and recommendation results. The
current main issue to cope with is not only recommending or retrieving the most relevant
items and content, but defining them ad hoc. Other relevant issues include personalizing
and adapting the information and the way it is displayed to the user’s current situation andinterests.
The workshop on Context-awareness in Retrieval and Recommendation is a forum forresearch on context-awareness in information retrieval, recommender systems and human
computer interaction. The fourth iteration of the workshop was organized in conjunction tothe 36th European Conference on Information Retrieval in Amsterdam, The Netherlands.

1Introduction

A core topic in Information Retrieval and Recommender Systems, context-awareness is addressed by a significant number of research papers, projects, etc. on a yearly basis, making
up a significant share of the technical program at conferences such as ECIR, RecSys, SIGIR,CHI, MobileHCI and related events. Context-awareness is a recognized methodology for improving the quality of information access and personalization systems and there exists a large
number of systematic and algorithmic variations of these methods. There is however also alarge variety in what is considered as context, this is also one of the key foci of this series ofworkshops, i.e. an attempt at formalizing not context itself, but rather the terminology usedthroughout the field.
In the scope of the CaRR workshop series (CaRR 2014 [8], CaRR 2013 [1], CaRR 2012 [2]and CaRR 2011 [3]), we have discussed the role of context referring to the personalizationof information. Context is generally referred to as different factors surrounding the user, theinformation object (or item), or the system. The location of the information interaction,
the weather at the time of the interaction, or the users mood are examples of context that

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have been presented and discussed during the CaRR Workshop Series. With CaRR, weaimed to invite the community to a discussion in order to find new creative ways to support
context-awareness and exchange ideas between different communities.
The workshop took place on April 13th 2014 as a full-day workshop in conjunction withECIR’14 in Amsterdam, The Netherlands. The schedule included one keynote presentation,
followed by a set of paper presentations, and a concluding panel discussion on context-aware
retrieval and recommender systems. The workshop proceedings are available in the ACM
DL1 .
In the remainder of this report, we provide further details about the different parts of theworkshop and end with a brief discussion on the future of the topic.

2Keynote

The workshop keynote was given by David Elsweiler from the University of Regensburg. The
keynote, titled ”Behaviour with Search and Recommender Systems: what can it tell us? ”[4], covered users’ interactions with point of interest recommendation systems in different
contexts (location, interests, etc.) as well as users’ behavioral changes during the interactionwith such systems.

3Paper Presentations

There were four paper presentations during the workshop covering topics ranging fromlocation- and mobility-related context to contextual datasets and factorization algorithms
for continuous context modeling.
The presented papers were:• B. Lamche, U. Trottman, W. Woendl – Active Learning Strategies for Exploratory
Mobile Recommender Systems [6]• M. Sappelli, S. Verberne, S. Koldijk, W. Kraaij – Collecting a dataset of information
behaviour in Context [9]• S. Mizzaro, M. Pavan, I. Scagnetto, I. Zanello – A Context-Aware Retrieval Systemfor Mobile Applications [7]• B. Hidasi, D. Tikk - Approximate Modeling of Continuous Context in Factorization
Algorithms [5]4Panel Session

After the presentations, the workshop continued with a fishbowl panel session where allworkshop attendees were invited to participate. The mixed background of the participants(research and industry, as well as various research topics), generated a very active and interactive discussion. The topics focused on the difference between search and recommendation.
After a lengthy discussion, there was an agreement on a general difference in usage purpose
between the two. Even though techniques and concepts such as scoring and ranking are used1

http://dl.acm.org/citation.cfm?id=2601301

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in both retrieval and recommendation, the usage is generally different. Other topics covered
were when personalization and contextualization should be used, how to avoid getting stuckin the filter bubble, and in what cases these can actually be harmful instead of useful.

5Conclusion

The 2014 CaRR workshop was the first in the series to be orgnized at a core IR conference,
which reflected on the panel discussions and - to some extent - on the participants. The
discussions at this event tended go into more technical details than on the workshop editionsorganized at ACM IUI (2011 and 2012 editions).
The workshop was successful in bringing people from the research community and industry together, and in discussing and addressing some important issues in the area, emphasizing
the importance of contextualization, personalization and utility of retrieval and recommendersystems.

Acknowledgements
We would like to thank the organisers of ECIR for providing a venue for this workshop. Further, we acknowledge the efforts of the members of the programme committee and additional
reviewers, including:Luca Maria Aiello (Yahoo! Research, Spain), Omar Alonso (Microsoft, USA), Nicola
Barbieri (Yahoo! Research, Spain), Alejandro Bellogn (UAM, Spain), Robin Burke (DePaulUniversity, USA), Pablo Castells (UAM, Spain), Juan M. Cigarran (UNED, Spain), Paolo
Cremonesi (Politecnico di Milano, Italy), Marco De Gemmis (University of Bari, Italy), Ana
Garcia-Serrano (UNED, Spain), Alexandros Karatzoglou (Telefonica R&D, Spain), Antonio
Krger (DFKI, Germany), Martha Larson (TU Delft, The Netherlands), Neal Lathia (University of Cambridge, UK), Pasquale Lops (University of Bari, Italy), Bamshad Mobasher(DePaul University, USA), Andreas Nrnberger (OVGU, Germany), Francesco Ricci (FreeUniversity of Bozen-Bolzano, Italy), Yue Shi (TU Delft, The Netherlands), Armando Stellato (University of Tor Vergata, Italy), Domonkos Tikk (Gravity R&D, Hungary), Arjen deVries (CWI, The Netherlands),

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409–412, New York, NY, USA, 2012. ACM.
[3] Ernesto William De Luca, Alan Said, Matthias Böhmer, and Florian Michahelles. Workshop on context-awareness in retrieval and recommendation. In Proceedings of the 16th

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International Conference on Intelligent User Interfaces, IUI ’11, pages 471–472, NewYork, NY, USA, 2011. ACM.
[4] David Elsweiler. Behaviour with search and recommender systems: What can it tell us?
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[6] Béatrice Lamche, Uwe Trottmann, and Wolfgang Wörndl. Active learning strategies
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[7] Stefano Mizzaro, Marco Pavan, Ivan Scagnetto, and Ivano Zanello. A context-aware
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[8] Alan Said, ErnestoWilliam De Luca, Daniele Quercia, and Matthias Bhmer. 4th workshop on context-awareness in retrieval and recommendation. In Maarten de Rijke, TomKenter, ArjenP. de Vries, ChengXiang Zhai, Franciska de Jong, Kira Radinsky, and Katja
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