WORKSHOP REPORT

Report on the Seventh International Workshopon Location and the Web (LocWeb 2017)
Workshop held at WWW2017
Dirk Ahlers1 and Erik Wilde2
1NTNU – Norwegian University of Science and Technology, Trondheim, Norway,
dirk.ahlers@ntnu.no2
CA Technologies, Zürich, Switzerland, dret@ca.com

Abstract
Location is an important feature in describing and understanding the real world. Consequently, it appears in many Web applications and mining approaches as a cross-cutting
issue. LocWeb 2017 continues a workshop series addressing issues at the intersection oflocation-based services and Web architecture and was held in conjunction with WWW 2017.
It combines geospatial search, information management, and Web architecture, with a main
focus on location-aware information access. The LocWeb 2017 workshop drew contributions
from various fields, including transportation and mobility analytics, social media, and urbanplanning. It further featured keynotes on indoor Web usage and Web standards. This reportbriefly discusses the theme and the contributions of the workshop.

1

Introduction

Location has quickly moved into the mainstream of the Web, and the mobile Web in particular. It also continues to be a strong driver of applications and research activities. We now see
an increasing demand for more sophisticated location-based services, involving more powerful mechanisms in terms of information retrieval, mining, analytics, and semantics. New
application areas for Web architecture, such as the Internet of Things (IoT) and the Web ofThings (WoT), also mean that there will be increasingly rich and large sets of resources forwhich location is highly relevant.
Following the successful LocWeb workshops held in 2008, 2009, 2010, 2014, 2015, and2016, LocWeb 2017 continues the workshop series, addressing issues at the intersection oflocation-based services and Web architecture. Its focus lies in Web-scale systems and services
facilitating location-aware information access. The location topic is understood as a crosscutting issue equally concerning Web information retrieval, semantics and standards, andWeb-scale systems and services. LocWeb is an integrated venue where the location aspect
is discussed in depth within an interdisciplinary community. The workshop helps advancing

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the integration of the geospatial dimension into the Web, and promotes challenging researchquestions.
LocWeb 2017 is the seventh event in the workshop series and took place on April 4th,2017 in Perth, Australia, co-located with WWW2017,the 26th International World Wide
Web Conference, which was held in the Perth Convention and Exhibition Centre.1
Details, including most of the presentations made at the workshop and information about
previous editions, can be found on the workshop homepage2 and on the workshop series
homepage3 . The LocWeb report for 2016 has been published in SIGIR Forum [1] as well as
those for previous years.

2Workshop Theme and Topics

LocWeb solicits submissions under the main theme of Web-scale Location-Aware Information
Access. Subtopics include (1) geospatial semantics, systems, and standards; (3) large-scale
geospatial and geo-social ecosystems; (3) mobility; (4) location in the Web of Things; and(5) mining and searching geospatial data on the Web. The workshop encourages work describing Web-mediated or Web-scale approaches that build on reliable foundations, and thatthoroughly understand and embrace the geospatial dimension.
The workshop’s topics of interest were: Location-Aware Information Access, LocationAware Web-Scale Systems and Services, Location in the Internet/Web of Things, Large-scale
Geospatial Ecosystems, Standards for Location and Mobility Data, Geospatial aspects ofSmart Cities, Location in Unstructured and Semi-Structured Information Sources, Location
Semantics, Modeling Location and Location Interaction, Geo-Social Media and Systems,
Location-Based Social Networks, Geospatial Web Search and Mining, Visual Analytics ofGeospatial Data on the Web, Location-Based Recommendation, Geo-Crowdsourcing, Mobile
Search and Recommendation.

3Workshop Contributions

The workshop had an interdisciplinary combination of contributions, with one researchkeynote, one applications keynote and three full papers. The proceedings [2] are available
in the ACM Digital Library and also from the conference page4 as part of the WWW 2017
Companion. Slides for the papers and keynotes are available from the workshop homepage.

3.1

Keynotes

The first keynote was given by Martin Tomko on the topic of Understanding Indoor Behavior:
Where, What, with Whom? [5], also offering a different view of Australia as one of the mosturbanized places. The keynote discussed an ongoing research project based on a rich datasetof indoor movement, which uses Internet access points to track the movement of people
through a large mall in Australia. This work combines previous separate strands of research
1geo:32◦ 57’25”S;115◦ 51’13”E
http://dhere.de/locweb2017/3
http://dhere.de/locweb/
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http://www2017.com.au/
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about human mobility or of local search. By logging HTTP traffic combined with the roughlocations estimated by the served access point areas, new insights into information needs andinformation access in an indoor scenario are possible. Some methods used were to understandindoor behaviour by information needs and separate into facets of physical, information, andsocial behaviour, with a specific focus on spatial transitions, for example through space,through floor levels, or through functional areas. The main take-away from the analysisof the data is that analyzing indoor behavior still is a relatively under-researched area, inparticular in light of the fact that the data can be spotty and thus assumptions have to
be made that can help explain the spottiness, and still derive useful pragmatic behavioral
insights from the dataset.
A technical keynote titled Standards Update: GeoJSON and Geo APIs was given by ErikWilde. This brief update discussed the current set of standardization worked on by the IETF
GeoJSON working group, as well as a set of possible future work items, including GeoJSONText Sequences. GeoJSON is now available as IETF RFC 7946 with its own mime-typeapplication/geo+json to provide a clear distinction to previous standards. The update also
briefly touched upon the fact that the standards produced by this group can serve as astarting point for Web-oriented APIs for geolocation-aware services, and how API designs
can take advantage of well-known standards by using and possibly extending them for certain
aspects of the API design.

3.2

Paper Presentations

The workshop accepted 3 full papers. Our PC members provided more than 3 reviews
per paper on average. With 5 papers submitted, we had an acceptance rate of 60%. We
had international author groups from Europe and South America, with no cross-country
authorships.
The first talk by Gilles Vandewiele presented joint work with Pieter Colpaert, Joachim
Van Herwegen, Olivier Janssens, Ruben Verborgh, Erik Mannens, Femke Ongenae, and Filip
De Turck on Predicting train occupancies based on query logs and external data sources [6].
The paper presented an approach of predicting train occupancies for the public transit system
in Belgium through crowdsourcing and external data. It also provided a good insight into
the practical problems of getting access to valuable data sources, and the challenges of using
the available ones to solve a given problem.
In the next paper, Marco Brambilla presented work with Stefano Ceri, Florian Daniel, andGianmarco Donetti with the title Spatial Analysis of Social Media Response to Live Events.
The Case of the Milano Fashion Week [3]. This paper discussed a dataset extracted fromsocial media that is looking at how people move around and post about the Milano fashion
week as an example of an event spanning large parts of a city. It provides interesting insights
into events that attract a lot of attention and have a variety of spatially different venues
that people have to get to. It also provides interesting insights into the lack of informationthat social media data inherently has, such as the question how the geolocation of a social
media post is related to the geolocation of the person creating that post and the issue that
popularity is a bad predictor of geospatial spread.
Finally, the paper Could data from location-based social networks be used to support
urban planning? [4] was presented by Tiago Lima as joint work with Rodrigo Smarzaro
and Clodoveu Davis Jr. This paper takes a broader view and looks at social media data
as a possible input for social urban planning by estimating quality of life indicators for cityACM SIGIR Forum

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Figure 1: Perth city views: One Eleven office building house name sign; skywalk around the bus
terminal and conference center in the business district.
regions. It demonstrates that some insight can be gained from analyzing social media, butthat the general challenges about social media accuracy pose a challenge when it comes tousing it as hard facts for planning activities.

4Discussion Session

This discussion session was started by the organizers with an introduction of location-relatedcharacteristics of the hosting city encountered. This was to highlight the highly local andspecific uses of location and place, show how this can lead to location being highly contextand city-dependent, and giving seeds for discussion.
Two examples we found in Perth are shown in Fig. 1. The first is the house number andhouse name sign for the office building One Eleven, 111 St Georges Terrace, Perth. Here, thebuilding name reflects the house number, although spelled one eleven instead of one hundred
eleven. Depending on the type of geoparser used for either address extraction from text,or for visual recognition, this may lead to unintended results as either the house name andnumbers could be confused or the name only recognized as 11 and not 111.
This started more discussions on certain peculiarities on house numberings in Australia.
For example, as in other rural areas, house numbers in the Australian outback could rather
show the distance to a last landmark. In the huge outback, this can actually be the numberof kilometers from the last settlement on that road. This will of course stretch the numberedplaces on a rural road massively and needs a very different set of assumptions that in urban
or in European rural regions, for example. Another example given was that for long streets
crossing multiple zip codes, house numbering may restart for each zip code instead of runningthrough. This makes the number mostly pointless for disambiguation and makes the district
essential to identify one of multiple street/housenumber combinations.
The second example shown in Fig. 1 concerns overlapping structures, in this case thewalkways to the conference center. These wind through and around the center and the bus

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Vol. 51 No. 1 June 2017station below, but also connect some of the buildings in the business district. In addition,some of the walkways connect and pass through buildings, blurring the distinction between
public and private as well as indoor and outdoor space. Such structures are a recurring
theme as they also appeared previous discussions such as last year [1].
Starting from this, the discussion then also revolved around general handling of elevationand the difficulty of sourcing accurate elevation and topology maps. A further point was thegranularity and resolution of these and more discussion around data availablity.

5Conclusion and Future Directions

LocWeb 2017 attracted a wide variety of contributions, reflecting the cross-cutting issue oflocation on the Web, combining transportation, mobility, social media, and urban planning
for a range of analyses and applications. At WWW2017 we could reach many interested andinteresting participants from industry and academia. The conference itself also hosted many
interesting papers including the geospatial topic. It also hosted an event based around theW3C Spatial Data on the Web WG. For the afternoon of the workshop day we invited allLocWeb attendees to join the afternoon sessions of the tutorial The Lifecycle of Geotagged
Data 5 , by Rossano Schifanella, Bart Thomee, and David Shamma.
LocWeb2017 again showed that location and the Web is a very fruitful combination andthat the increasing availability of data, standards, and methods allows for improving analyses
and applications as well as develop the overall geospatial topic. We look forward to more
exciting contributions in this field.

Acknowledgements
We would like to thank the authors of submitted papers for their efforts, and all attendees ofLocWeb 2017 for making this an interesting and interactive workshop. We specially thankMartin Tomko for his keynote. We are especially grateful to the members of the programcommittee for their hard work in reviewing the contributions and providing substantial feedback on a tight deadline:
Andreas Henrich, Universität Bamberg, Germany; Arjen de Vries, Radboud University; Bruno Martins, University of Lisbon, Portugal; Carsten Keßler, Hunter College, City
University of New York; Chandan Kumar, University Koblenz-Landau, Germany; Claudia
Hauff, Delft University, Netherlands; Clodoveu Davis, Universidade Federal de Minas Gerais,Brazil; Christoph Trattner, Know-Center, Austria; Christopher Jones, Cardiff University,UK; Faegheh Hasibi, Norwegian University of Science and Technology; Francisco LópezPellicer, Universidad Zaragoza, Spain; John Krogstie, Norwegian University of Science andTechnology; Lisette Espı́n-Noboa, GESIS – Leibniz-Institute for the Social Sciences; Luca
Maria Aiello, Bell Labs; Massimiliano Ruocco, Norwegian University of Science and Technology; Rainer Simon, AIT Austrian Institute for Technology; Ross Purves, Universität Zürich,Switzerland; Steven Schockaert, Cardiff University, UK; Yana Volkovich, Appnexus.
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https://sites.google.com/view/geocycle-www17/

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References[1] D. Ahlers and E. Wilde. Report on the Sixth International Workshop on Location andthe Web (LocWeb 2016). SIGIR Forum, 50(2):51–57, Dec. 2016. URL: http://sigir.
org/wp-content/uploads/2017/01/p051.pdf, doi:10.1145/3053408.3053420.
[2] D. Ahlers and E. Wilde, editors. LocWeb ’17: Proceedings of the 7th International
Workshop on Location and the Web, WWW ’17 Companion. International World Wide
Web Conferences Steering Committee, 2017.
[3] M. Brambilla, S. Ceri, F. Daniel, and G. Donetti. Spatial Analysis of Social MediaResponse to Live Events. The Case of the Milano Fashion Week. In Ahlers and Wilde[2], pages 1457–1462. doi:10.1145/3041021.3051698.
[4] T. Lima, R. Smarzaro, and C. Davis, Jr. Could data from location-based social networks
be used to support urban planning? In Ahlers and Wilde [2], pages 1463–1468. doi:
10.1145/3041021.3051700.
[5] M. Tomko. Understanding Indoor Behavior: Where, What, with Whom? In Ahlers andWilde [2], pages 1455–1457. doi:10.1145/3041021.3051697.
[6] G. Vandewiele, P. Colpaert, J. V. Herwegen, O. Janssens, R. Verborgh, E. Mannens,F. Ongenae, and F. D. Turck. Predicting train occupancies based on query logs andexternal data sources. In Ahlers and Wilde [2], pages 1469–1474. doi:10.1145/3041021.
3051699.

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