WWW 2015 WORKSHOP REPORT

Report on the Fifth International Workshop onLocation and the Web (LocWeb 2015)
Dirk Ahlers1 , Erik Wilde2 , and Bruno Martins3
1NTNU – Norwegian University of Science and Technology, Trondheim, Norway,
dirk.ahlers@idi.ntnu.no2
Siemens, Berkeley, USA, dret@berkeley.edu
3
ULisboa, IST and INESC-ID, Lisbon, Portugal, bruno.g.martins@ist.utl.pt

Abstract
Location is a major feature for describing the real world, appearing in many Web applications and search systems as a cross-cutting issue. Envisioning the establishment of anadequate venue for the location topic, LocWeb 2015 continued a workshop series at theintersection of geospatial search, information management, and Web architecture, with amain focus on location-aware information access. Contributions to the workshop highlighted
various fields that benefit from a tailored approach towards location features. LocWeb 2015
showed an interdisciplinary mix of contributions, featuring one keynote and three full papers.
In this report, we provide a brief overview of the workshop and its contributions.

1Introduction

Location has become a mainstream feature of the (mobile) Web and it continues to be astrong driver of research activities, related to a wide range of topics that include search,retrieval, mining, extraction, analytics, mobility, services, and systems. After the initialboost and consolidation of approaches based on the simple use of geospatial coordinates, wenow see an increasing demand for more sophisticated systems, stronger retrieval, mining,and analytics solutions, and more powerful semantics. Location is playing a key role as acontext factor for users, but also as the implicit or explicit place of resources and people.
It also is an important factor in mobile and geo-social applications, and it is behind many
geospatially-aware Web data mining developments.
LocWeb, the Workshop on Location and the Web, has taken up location as its main
topic, understanding it as a cross-cutting issue. LocWeb has been a ‘traveling’ workshop,having been held before at venues as diverse as WWW, CHI, IoT, and CIKM. Following up
on this background, the main objective of the workshop was to bring together a communityof researchers at the intersection of location and location-aware services and the Web andWeb architecture, for exchanging ideas and discussing and developing the role of location.
LocWeb 2015 is the fifth in the series and took place on May 19th 2015 in Florence, Italy,

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co-located with WWW 2015, the 24th International World Wide Web Conference (WWW2015), which was held in the Fortezza da Basso (geo:43.782,11.249).
The LocWeb workshop series envisions establishing an integrated venue where the location
aspect can be discussed in depth within an interested community. Its focus lies in Web-scale
systems and services facilitating location-aware information access. The location topic isseen as a cross-cutting issue, equally concerning Web information retrieval, semantics andstandards, and Web-scale systems and services. New application areas for Web architecture,such as the Internet of Things (IoT) and the Web of Things (WoT) mean that there will be
increasingly rich and large sets of resources for which location is highly relevant. In the longterm, we expect LocWeb to further the integration of the geospatial dimension into the Web,and promote challenging research questions related to location-aware information access.
Further details, including most of the presentations made at the workshop and information
about previous editions, can be found on the workshop homepage1 and on the workshop series
homepage2 . A report on LocWeb2014 has been previously published in SIGIR Forum [2].

2Workshop Theme and Topics

LocWeb solicited submission under the main theme of Web-scale Location-Aware Information Access. Subtopics included geospatial semantics, systems, and standards; large-scale
geospatial and geo-social ecosystems; mobility; location in the Web of Things; and mining
and searching geospatial data on the Web. The workshop encouraged interdisciplinary perspectives and submissions describing Web-mediated or Web-scale approaches that build on
reliable foundations, and that thoroughly understand and embrace the geospatial dimension.
We were also interested in studies tying into ongoing W3C activities such as Web of Things,
Social Web, Data Activity, and Geolocation WG.
The workshop’s topics of interest were: Location-Aware Information Access, LocationAware Web-Scale Systems and Services, Location in the Web of Things, Large-scale Geospatial Ecosystems, Standards for Location and Mobility Data, Location Semantics, Modeling
Location and Location Interaction, Geo-Social Media and Systems, Location-Based Social
Networks, Geospatial Web Search and Mining, Visual Analytics of Geospatial Data on theWeb, Location-Based Recommendation, Geo-Crowdsourcing, and Mobile Search and Recommendation.

3

Workshop Contributions

LocWeb 2015 showed an interdisciplinary mix of contributions, featuring one keynote andthree long papers. This section briefly overviews the different contributions.

3.1

KeynoteThe workshop keynote was given by Daniele Quercia, titled Chatty, Happy, and Smelly
Maps [6]. Daniele gave compelling insights into how people’s experience of cities can beunderstood in great detail using today’s vast range of available data. He described recent
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studies combining modern data analytics with classical methods and insights from the socialsciences, from people such as Jane Jacobs, Stanley Milgram, or Kevin Lynch.
In his keynote, Daniele repeated a theme consistent with last year’s keynote, stressing theideia that there is significant value in classic theories, especially when combining them withmodern computational approaches and data availability. Nowadays, not only can experiments
be scaled up, but they can also be conducted in a much higher spatial granularity, to findsimilarities and differences within cities.
Daniele drew a line from classic experiments to the availability of modern city maps andwayfinding applications. He then described his own research work, which aims to create newmaps and wayfinding approaches based on emotional responses to the city. He described theuse of crowdsourcing to analyse and categorise pictures of the city, to then provide navigation
not along the shortest, but instead the happiest paths, in the sense that they would be moreenjoyable. Envisioning extensions to his work, Daniele ventured into new territory basedon sound (e.g., quiet paths) or smell, which needs new data collection methods. He showedinteresting parallels to other fields, such as olfactory research or perfumery, from which totake hints to map smells and scale measurements up to a city level.

3.2

Paper Presentations

The workshop accepted 3 full papers. We had more than 5 reviews per paper and the overall
acceptance rate was 50%. We had international author groups from Europe and Asia, butthere were no cross-country authorships. Full papers had 20 minutes of presentation and 10
minutes of time for discussion.
The proceedings [1] are available in the ACM Digital Library3 and also directly from theconference page4 , as part of the WWW 2015 Companion. Slides for all papers are available
from the workshop homepage.
The first paper, titled Reconnecting Digital Publications to the Web Using Their SpatialInformation [4] by De Meester, De Nies, Verborgh, Mannens, and Van de Walle, discussed
an interesting application scenario for location in ebooks. They use extracted concepts fromthe contents of ebooks to estimate a geospatial footprint, and thus are able to dynamicallylink from books to maps, to enrich the reading experience. They also propose a method to do
this not only for location references, but for arbitrary concepts through the use of DBPedia.
In these cases, a mix of related links and related geospatial concepts from the abstract canprovide rough location estimates in the form of footprints.
In Verification of POI and Location Pairs via Weakly Labeled Web Data [3], Chuang andChang take on the issue of the maintenance of POI (point of interest) databases, especiallyto determine whether a POI, or more formally, the relation of an entity to a location, isoutdated. They propose to collect evidence via Web search engines, with queries basedon names and locations. The collected information reflects a number of features, including
number, freshness, and similarity of results. This can give hints towards some types of POIlocation relationships that have changed. While the task still remains a hard challenge, theauthors showed some promising results.
The paper The Role of Geographic Information in News Consumption [5] by Gebremeskel
and de Vries looked at another type of location use. The authors investigated the behaviourof readers of online news articles based on log files from a number of portals. Their goal was34

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Figure 1: House numbers in Florence. Building (entrance) number 6 with signs denoting businesses
32 and 30, seen from left to right.
to investigate the influence of the spatial distance of readers to the spatial focus of different
news outlets on reading behaviour. Their analysis allowed them so see which news portals
are more focused to certain regions compared to a more broad readership.

4Discussion Session

The discussion session, at the end of the workshop, started with an introduction from theorganizers into how location, and location use, can be highly local and context-dependent.
An interesting example, based on the city of Florence and illustrating how local knowledge
is needed to understand the city and its locations, was initially discussed.
The house numbering scheme in Florence, especially its medieval old city, is particular; ituses two sets of house numbers denoted by suffixes.5 Houses are given numbers with an N,
which denotes nero = black, and individual businesses are given numbers with an R, whichmeans rosso = red. The red numbers are not always actually coloured, and they may also
appear implicitly as businesses by their sequence and the way they are attached to buildings.
Because businesses and homes are mixed, this leads to two distinct sequences of numbering
within a street.
While it is rather simple to extend address parsers to include and understand the separation, geocoding and mapping needs more work. A building may have the same number
twice, both as 2 (or 2n) and as 2r. Multiple entrances can occur as well, leading to common
numberings such as 1 and 1A (which can be written as 1/A), even on the same building.
On the other hand, business numbers are assigned consecutively, with multiple ones for one
building as in some cases, each arched door of a building could house a small shop.
5

http://wiki.openstreetmap.org/wiki/Florence_house_numbers_import,
http://www.yourwaytoflorence.com/tourism/info/street.htm

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A possible sequence of numbers running a street may be6 : 4 24 26 28 30 32 6 34 36 38
40 42 8. These are all even, and odd numbers are on the other side of the street. 4, 6, 8 arehouse entrances, the others are businesses. Fig. 1 shows the highlighted sequence of 30 32 6.
Here 6 denotes the left entrance to the house, and 30 and 32 (set higher and in a differentplaque style) denote the individual arches on the ground floor housing one or multiple shops.
Because the home and business density can vary (as business house numbers may also runhigh quickly), an error in address parsing (for example not identifying an R) could put aplace quite far away up to hundreds of meters from its actual position.
Such errors are present at the time of writing in some mapping services for parts of thecity, often induced by Web pages that do not write their addresses in the expected style but
also strongly for roads where the two sequences are only captured as one in the underlying
street database and subsequently both distinct numberings are matched to only one sequence.
Starting from this example, the discussion continued along the lines of local peculiarities,
addressing location references that are not used as would be expected, and also general issuesof extracting or parsing locations. Open issues were also identified in different fields. These
include how to integrate geospatial relevance or features into larger feature sets and how
to fine-tune their impact together with temporal or topical features, how to verify places
mentioned on the Web in general, and how to include social networks and social indicators.
The issue of varying levels of granularity was also discussed, as well as difficulties indealing with derived locations of non-spatial concepts, or in dealing with non-point-based
locations is an intuitive and computationally simple way.
Further issues were scope detection for geospatial data and the use and impact of distancemetrics in different applications. All these aspects tie with and extend the discussion of open
issues at last year’s workshop [2].

5Conclusion and Future Directions

The 2015 Workshop on Location and the Web had its main focus on location-aware information access. The workshop featured an interesting variety of contributions, with one keynote,
three full papers, and a final discussion session. Presenters and attendees, both from industry and academia, debated current important aspects in the field, as well as open issues andfuture research directions. Location continues to be an important issue in IR, mostly due toits multifaceted potential. However, unified approaches are rare and researchers often haveto build very tailored systems to support their specific use case. On the other hand, more andmore complex issues are being approached, showing a definite improvement towards morecomplex and more realistic uses of location.

Acknowledgements
We first would like to thank the authors of submitted papers for their efforts, and all attendees
for making LocWeb 2015 an interesting, interactive and diverse workshop. A special thanks
goes to Daniele Quercia for giving a very inspiring keynote. We are especially grateful to the6This example is from Via de’ Tornabuoni which can be examined in, e.g., OpenStreetMaps (which has very
highly detailed house numbers available) or Google StreetView.

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members of the program committee for their hard work in reviewing the contributions andproviding substantial feedback on a tight deadline:
Keith Cheverst, Lancaster University; Clodoveu Davis, Universidade Federal de MinasGerais; Arjen de Vries, CWI; Max Egenhofer, University of Maine; Claudia Hauff, Delft
University of Technology; Andreas Henrich, University of Bamberg; Carsten Keßler, HunterCollege, City University of New York; Francisco J. Lopez-Pellicer, University of Zaragoza;
Vanessa Murdock, Microsoft; Kjetil Nørvåg, Norwegian University of Science and Technology(NTNU); Ross Purves, University of Zürich; Massimiliano Ruocco, Norwegian University ofScience and Technology (NTNU); Mark Sanderson, RMIT University; Steven Schockaert,Cardiff University; Rainer Simon, Austrian Institute of Technology; Johannes Schöning,Hasselt University; Torsten Suel, New York University; Bart Thomee, Yahoo! Research;
Christoph Trattner, KMI, TU-Graz; Yana Volkovich, Barcelona Media – Innovation Centre;
Xing Xie, Microsoft Research;
Finally, we thank the organizers of WWW2015 for hosting the workshop, as well as ACM
and Sheridan for their support.

References[1] D. Ahlers, E. Wilde, and B. Martins, editors. LocWeb ’15: Proceedings of the 4th International Workshop on Location and the Web, WWW 2015 Companion. International
World Wide Web Conferences Steering Committee, 2015.
[2] D. Ahlers, E. Wilde, and B. Martins. Report on the Fourth Workshop on Location andthe Web (LocWeb 2014). SIGIR Forum, 49(1):35–40, June 2015.
[3] H.-M. Chuang and C.-H. Chang. Verification of POI and Location Pairs via Weakly
Labeled Web Data. In [1], pages 743–748.
[4] B. De Meester, T. De Nies, R. Verborgh, E. Mannens, and R. Van de Walle. Reconnecting
Digital Publications to the Web Using Their Spatial Information. In [1], pages 749–754.
[5] G. G. Gebremeskel and A. P. de Vries. The Role of Geographic Information in News
Consumption. In [1], pages 755–760.
[6] D. Quercia. Chatty, Happy, and Smelly Maps. In [1], pages 741–741.

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