LocWeb2021 at WWW2021

The 11th International Workshop on Location and the Web

We are happy to announce that LocWeb2021 has been accepted as a workshop at the WWW2021 conference!

Monday, 12. April 2021
In conjunction with WWW 2021 The Web Conference, Ljubljana, Slovenia (Online)

Workshop theme

Location and geospatial analytics are important aspects in a wide range of Web research and systems. The location topic is seen as a cross-cutting issue equally concerning information access, semantics and standards, social analysis and mining, and Web-scale systems and services. We believe that the Web conference should contain a workshop exploring the connection of the Web to the real physical and spatial world. As a cross-cutting issue, location can vastly benefit from this dedicated venue. We aim for a highly interactive, collaborative full day workshop with ample room for discussion and demos that will explore and advance the topic, with contributions from research and industry. LocWeb 2021 will continue a successful workshop series at the intersection of location-based analytics and Web architecture. It focuses on Web-scale services and systems facilitating location-aware information access as well as spatial social behavior analytics as part of social computing. Location has high importance in Web-based designs, and it continues to provide challenging research questions. It additionally has a role in large systems of social and societal importance, and we aim to explore this connection further under the topics of data science for social good and in ways to improve people’s lives. Furthermore, the past year has brought massive disruptions in how we go about our lives, how we use and experience the physical world around us, and a move to virtual spaces. The workshop also examines these shifts.

The objective of the workshop is to bring together a community of researchers at the intersection of location and the Web, under the main topic of spatial social behavior, location-aware information access, Web-scale systems, and societal and social good. LocWeb addresses location as a cross-cutting issue in web research and technology that connects the online world to the physical spatial world. It examines location aspects in the domains of social computing, search, analytics, mobility, apps, services, standards, and systems. It also opens up larger societal challenges, the use of such systems, their governance questions, and the connection to spatial data science for social good.

Another topic we would like to explore this year is the blurring of physical and virtual/online spaces, which has been accelerated with the mass move to online sessions and conferences due to Covid-19 mitigation measures. This has shifted the understanding and experience of physical locations for collaboration. Much work has appeared in the meantime analysing large-scale shifts in mobility patterns, thus bridging the physical and virtual implications. In a way, location has diffused into the background for certain activities that were before decidedly physical, but the understanding of experience of place can allow new perspectives.

Call for Papers

LocWeb will solicit submissions under the main theme of Web-scale Location-Aware Information Access and spatial social computing. Subtopics include (i) geospatial semantics, systems, and standards; (ii) large-scale geospatial and geo-social ecosystems; (iii) mobility; (iv) location in the Web of Things; and (v) 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 that thoroughly understand and embrace the geospatial dimension.


The topics are designed to reflect the multitude of fields that demand and utilize location data. We encourage submissions to take an interdisciplinary perspective at the topic of location on the Web.

  • Location-Aware Information Access
  • Spatial Social Behavior
  • Location-Aware Web-Scale Systems and Services
  • Geospatial Data Science for Social Good
  • Experience of virtual and physical place through online mediation
  • Physical and virtual/online spaces for collaboration and information access
  • Urban Planning and Citizen Engagement
  • Geospatial aspects of Smart Cities
  • Location in the Internet/Web of Things
  • Open Geospatial Web Data
  • Location prediction in social media and the Web
  • Influence modeling and processing in static and dynamic spatio-social graphs
  • Evaluation of frameworks, metrics and algorithms
  • Large-scale Geospatial Ecosystems
  • Standards for Location and Mobility Data
  • Modeling Location and Location Interaction
  • Location-Based Social Networks
  • Geospatial Web Search and Mining
  • Mobile Search and Location-Based Recommendation


This year, we are running a joint programme of the LocWeb and TempWeb (11th Temporal Web Analytics Workshop) workshops with joint topical sessions on Monday, April 12. All times are in the CET timezone (GMT+2).

You will find the programme also in the MITeam system. When you login there, you can join either LocWeb or TempWeb and should join the same room. In case of issues, try to join the TempWeb room.

Session 1: User Behavior
Chair: Dirk Ahlers (NTNU, Trondheim) and Marc Spaniol (University of Caen)
11.00-11.15: Introduction to the joint Workshop
11.15-12.00: Keynote: Learning Spatio-Temporal Behavioural Representations for Urban Activity Forecasting. Flora Salim (RMIT, Melbourne, Australia) [LocWeb]
12.00-12.30: Cross-city Analysis of Location-based Sentiment in User-generated Text. Christopher Stelzmüller (Johannes Kepler University Linz, Austria), Sebastian Tanzer (Johannes Kepler University Linz, Austria) and Markus Schedl (Johannes Kepler University Linz, Austria) [LocWeb]

Session 2: Networks & Graphs
Chair: Dirk Ahlers (NTNU, Trondheim)
14.00-14.30: PaCo: Fast Counting of Causal Paths in Temporal Network Data. Luka Petrovic (University of Zurich, Switzerland) and Ingo Scholtes (University of Wuppertal, Germany) [TempWeb]
14.30-15.00: Understanding & Predicting User Lifetime with Machine Learning in an Anonymous Location-Based Social Network. Jens Helge Reelfs (Brandenburg University of Technology, Germany), Oliver Hohlfeld (Brandenburg University of Technology, Germany), Max Bergmann (Brandenburg University of Technology, Germany) and Niklas Henckell (The Jodel Venture GmbH, Germany) [LocWeb] [slides]
15.00-15.30: IP Geolocation using Traceroute Location Propagation and IP Range Location Interpolation. Ovidiu Dan (Microsoft Bing, USA), Vaibhav Parikh (Microsoft, USA). and Brian D. Davison (Lehigh University, USA) [LocWeb]

Session 3: Analytics & Visualization
Chair: Marc Spaniol (University of Caen)
16.00-16.30: Learning to Persist: Exploring the Tradeoff Between Model Optimization and Experience Consistency. Dmitri Goldenberg (Booking.com, Israel), Guy Tsype (Booking.com, Israel), Igor Spivak (Booking.com, Israel), Javier Albert (Booking.com, Israel) and Amir Tzur (Booking.com, Israel) [TempWeb]
16.30-17.00: Analysis and visualisation of time series data on networks with pathpy. Jürgen Hackl (University of Liverpool, UK), Ingo Scholtes (University of Wuppertal, Germany), Luka V. Petrovic (University of Zurich, Switzerland), Vincenzo Perri (University of Zurich, Switzerland), Luca Verginer (ETH Zurich, Switzerland) and Christoph Gote (ETH Zurich, Switzerland) [TempWeb]
17.00-17.30: Visualisation of Temporal Network Data via Time-Aware Static Representations with HOTVis. Vincenzo Perri (University of Zurich, Switzerland) and Ingo Scholtes (University of Wuppertal, Germany) [TempWeb]

Session 4: Time & Space
Chair: Ricardo Baeza-Yates (Northeastern University, USA; UPF, Spain; UChile)
18.00-18.45: Keynote: Telling Stories through Timelines. Ricardo Campos (Polytechnic Institute of Tomar) [TempWeb]
18.45-19.00: Panel (Ricardo Baeza-Yates, Dirk Ahlers, Omar Alonso and Marc Spaniol)

Accepted Papers

  • Understanding & Predicting User Lifetime with Machine Learning in an Anonymous Location-Based Social Network – Jens Helge Reelfs: Brandenburg University of Technology, Germany; Oliver Hohlfeld: Brandenburg University of Technology, Germany; Max Bergmann: Brandenburg University of Technology, Germany; Niklas Henckell: The Jodel Venture GmbH, Germany
  • IP Geolocation using Traceroute Location Propagation and IP Range Location Interpolation – Ovidiu Dan: Microsoft Bing, USA; Vaibhav Parikh: Microsoft, USA; Brian D. Davison: Lehigh University, USA
  • Cross-city Analysis of Location-based Sentiment in User-generated Text – Christopher Stelzmüller: Johannes Kepler University Linz, Austria; Sebastian Tanzer: Johannes Kepler University Linz, Austria; Markus Schedl: Johannes Kepler University Linz, Austria


  • Learning Spatio-Temporal Behavioural Representations for Urban Activity Forecasting – Flora Salim (RMIT)

Important Dates

Paper Submission Deadline: 11.Jan.2021 15.Jan.2021 31.Jan.2021 7.Feb.2021 (23:59 AoE Anywhere on Earth)
Acceptance Notification: 08.Feb.2021 17.Feb.2021
Final hard camera-ready: 1.Mar.2021
Workshop day: 12/15 April 2021 (Please note that WWW is spanning 2 weeks this year)

Submission instructions

We solicit full papers of 6-8 pages (including references etc.), and short papers of up to 4 pages describing work-in-progress or early results. Authors are invited to submit original, unpublished research that is not being considered for publication in any other forum. Workshop submissions will be evaluated based on the quality of the work, originality, match to the workshop themes, technical merit, and their potential to inspire interesting discussions. The review process is single blind, so please provide your name and affiliation.

Submit via easychair: https://easychair.org/conferences/?conf=locweb2021

Submissions have to follow the ACM styles and guidelines of the WebConf conference proceedings, using the “sigconf” format. Authors are pointed to the overall WWW2021 Ethics guidelines. Accepted workshop papers will be published in the WWW companion proceedings and the ACM Digital Library. For inclusion in the proceedings, at least one author of the accepted paper has to register for the workshop and present the paper (with the ‘author’ registration option).

Presenters are encouraged to bring demos to the workshop, to facilitate discussion and make the workshop more interactive.


Workshop organisers

Dirk Ahlers, NTNU, Norway, dirk.ahlers@ntnu.no
Erik Wilde, Axway
Rossano Schifanella, University of Turin, Italy
Jalal S. Alowibdi, University of Jeddah, Saudi Arabia

Programme Committee

Anastasios Noulas (New York University)
Andreas Henrich (University of Bamberg)
Arjen de Vries (Radboud Universiteit)
Auriol Degbelo (University of Münster)
Bruno Martins (IST and INESC-ID – Instituto Superior Técnico, University of Lisbon)
Carsten Keßler (Aalborg University Copenhagen)
Christopher Jones (University of Cardiff)
Clodoveu Davis (Universidade Federal de Minas Gerais)
Francisco J. Lopez-Pellicer (University of Zaragoza)
Lisette Espín-Noboa (GESIS – Leibniz-Institute for the Social Sciences, University of Koblenz-Landau)
Luca Aiello (IT University of Copenhagen)
Rainer Simon (AIT – Austrian Institute of Technology)
Ross Purves (University of Zurich)
Torsten Suel (New York University)
Pieter Colpaert (Ghent University)
Yana Volkovich (Xandr)