Methods to Study Flickr Users Behaviors

A couple of papers studying users behaviors in the context of online photo-sharing. Each has a specific angle on the data: social science (individual and group cooperation practices), data mining (who is looking at a photo) and visualization (understand the notion of place). I use them to inform the analysis of Flickr users practices to georeference and geotag their photos.

Prieur, C., Cardon, D., Beuscart, J.-S., Pissard, N., and Pons, P. (2008). The stength of weak cooperation: A case study on flickr. CoRR, abs/0802.2317.

Objective: Detail the concept of weak cooperation showing the great variety of uses (stockpiling, social media use, myspace like).
Data: 5M users, 150M photos, users, contacts, groups photos, comments, tags and favorites.
Methods: Distribution of flickr functionalities (contacts, comments, favorites); principal component analysis on correlation matrix to represent graphically the relations among nb photos, nb contacts (in/out), nb favorites (in/out); distribution of number of members and photos among Flickr groups, social graph with members of groups as nodes and proximity function between users from the similarity of the tags they use; define the social density of a group from the density of the social graph.

van Zwol, R. (2007). Flickr: Who is looking? In 2007 IEEE / WIC / ACM International Conference on Web Intelligence, pages 184–190. IEEE Computer Society.

Objective: Characterize user behaviors on temporal, social and spatial dimensions.
Data: 1.83M uploaded during 10 days and viewed over a period of 50 days.
Methods: Use a photo’s popularity to identify social networking and photo pooling. Distribution of photos views per bucket (a bucket groups the photos based on the number of views) 0-10%, 10-20%, 20-30%, 30-40%, 40-50% and > 50%. Same for the temporal dimension slices of time, and social dimension (comments, contacts, pools). Geographic distribution defined with two standard deviations (for the longitude and latitude) and a single value representing the geographic spreading of the photos views with the euclidian distance between the two standard deviations. This value is then applied to the slices.

Dykes, J., Purves, R., Edwardes, A. J., and Wood, J. (2008). Exploring volunteered geographic information to describe place: Visualization of the ’geograph british isles’ collection. In GIS Research UK (GISRUK 2008). Manchester Metropolitan University.

Objective: Understand the way language is used to describe landscape with geotagged photos
Data: 340,000 photographs with titles, comments and other metadata, georeference with at least 1km precision
Methods: Interactive and spatial treemaps of terms. Forcus on scene types (e.g. beach, village, mountain, hill) and scene type descriptors. Chi statistic maps of national trends for the selected combination of scene types. Spatial tag clouds to explore local variation in the terms.

Relation to my thesis:  Quantitative methods to understand user practices with online photo-sharing platforms in extensions to works such as Why We Tag: Motivations for Annotation in Mobile and Online Media

Understanding Human Mobility Patterns

In the line of Bruno Latour’s thoughts on the consequences of digital traces on social sciences, the current issue of Nature reports in its editorial “A flood of hard data” on the use of mobile-phone technique as an example of how modern information technologies are giving social scientists the power to make measurements that are often as precise as those in the ‘hard’ sciences:

Social scientists have long struggled with a paucity of hard data about human activities; people’s self-reporting about their social interactions, say, or their movement patterns is labour-intensive to collect and notoriously unreliable. In this case, the researchers obtained objective data on individuals’ movements from mobile-phone networks (albeit without access to any individual’s identity, for privacy reasons).

In “Understanding Individual Human Mobility Patterns“, a paper featured in the same issue is an example of this new approach. It reports on the study of movements of 100,000 people following their cellphone signals and found. Quite predictably, it reveals that “most people are creatures of habit”, inclined to move around the same few locations, occasionally given to long hops and despite the diversity of their travel history, humans follow simple reproducible patterns”,

Relation to my thesis: it is rather encouraging Nature reporting on the opportunity that digital traces represent for “It’s not an overstatement to say that these tools are fostering a whole new type of social science — with applications that go well beyond the conventional boundaries of the field.” and their influence on urban planning and the development of transportation networks… and some caution on the new approach that goes exactly in the direction of my thesis and exploring the practice behind the data to better inform the analysis of tourists presence and movements:

The goal of social science is not simply to understand how people behave in large groups, but to understand what motivates individuals to behave the way they do.

From Shoeboxes to Digital Footprints and Digital Shadows

The seminal report From Being Human addresses the issues around the explicit and implicit storage of our interactions and activities in public places, while shopping or on the web. The authors question how we will manage and harness the enormous digital footprints and shadows that are being created by and for everyone and cover many subjects are the core of my research.
The scale of the phenomenon

Furthermore, huge amounts of information are being recorded and stored daily about people’s behaviour, as they walk through the streets, drive their cars and use the Web. While much of this may be erased after a period of time, some is stored more permanently, about which people may be naively unaware. In 2020, it is likely that our digital footprints will be gigantic, distributed everywhere, and in all manner of places and forms.

Explicit digital footprints (emptying the shoeboxes)

The decreasing cost and increasing capacity of digital storage also goes hand-in-hand with new and cheap methods for capturing, creating and viewing digital media. The effect on our behaviour has been quite dramatic: people are taking thousands of pictures rather than hundreds each year. They no longer keep them in shoeboxes or stick them in albums but keep them as ever growing digital collections, often online. The use of Web services for photo-sharing is transforming why we take photos by reinventing what we do with them.

Implicit digital footprints (our digital shadows)

Data are also being collected on our behalf or about us for no apparent reason other than because the technology enables it – our digital shadows, if you like. Personal video recorders (PVRs) record TV programmes chosen by the viewer but also automatically store them based on the viewer’s viewing profile or other criteria. Similarly, new devices are beginning to appear, such as SenseCam (see ‘A Digital Life’, below), that can automatically capture all kinds of traces of everyday life, in the form of images, video, conversations and sounds. The same is true for GPS devices which now appear in cars, in mobile phones and even embedded into clothing. All of these are capable of producing and storing large volumes of location data about our comings and goings without any conscious effort on behalf of their owners.

Data are also being deliberately recorded about us by governments, banks and other institutions using technologies such as CCTV, ATMs and phone logging. In the UK, CCTV often generates recorded ‘feeds’ of conversations and actions, as well as logging exactly where these conversations and actions took place. Some workplaces have meeting rooms that capture the content of and activities around discussions held within them. Many public debates are recorded for posterity by editorialising CCTV: in the UK, the Houses of Parliament are captured on behalf of the nation by the BBC, for example. Most people’s financial transactions are logged too, each time a credit card is used. International phone calls from the US are routinely tapped and analysed for suspicious ‘terrorist’ topics (with advanced word-recognition software allowing interrogators to locate possible conversational threads which are then focused on more attentively).

Questions on the new challenges for how we design technologies
But digital records are merciless: a silly prank captured on a mobile phone and then uploaded to a photosharing site may haunt someone for the rest of their lives in a way it never did before.

• Will it be possible for people to delete digital memories captured by others? Now that there are digital tools that can record everything we say or do, how will this affect our own abilities and ways of remembering?
• What tools and technologies are needed to effectively manage vast quantities of personal data?
• How can the privacy and security of digital footprints be ensured to prevent misuse but at the same time allow them to be shared with others when needed?
• How do people find out about their digital footprint and what tools should be provided?

Questions of broader impact

• How should society manage the storage and access of human data ethically and responsibly?
• Will people have the right to have information removed from their digital footprints?
• What are the legal implications of a growing digital footprint that maintains a record of our present and past?
• Should people be informed of the information that is being captured about them, who has access to it and how it is being used?
• To what extent do we need to design technology that allows people both control and feedback about what kinds of data are being monitored?

Relation to my thesis: The report address the notions of implicit and explicit digital footprint (with the term digital shadows for the notion of implicit footprint) and the implications in for their management, the privacy of the people generating them and their misuse (in extension to Be Counted! Return Your Census!). However, it does not mention the benefits beyond the individual (storing for memory) and social (life sharing, coordination) interests such as better understanding societies (the massive consequences on social sciences) and cities.

Presentation: The co-evolution of taxi drivers and their in-car navigation systems

Yesterday, I presented at the 2008 Association of American Geographers Annual Meeting, the preliminary results of my ethnographic study on the use, adoption, and appropriation of satellite navigation systems by taxi drivers in Barcelona (slides). The abstract of the paper “The co-evolution of taxi drivers and their in-car navigation systems” co-authored with Josep Blat goes as follows:

In recent years, the relative market success of in-car navigation systems has symbolized the emergence of location-based services for wayfinding. This market success creates the opportunity to learn from real-world use of current location-aware systems in order to inform the design of future applications. With this aim, we are using an ethnographic approach to study the different ways taxi drivers rely on their navigation system. This work describes how location technologies impact the wayfinding practices and also how practices influence the appropriation of navigation systems. This co-evolution goes from the acquisition and setup of a navigation system to mastering the system shortcomings and limitations. Next, we study the reasons upon which a driver selects among the different modes of a navigation system and the other artifacts and tools (e.g. maps, street directories, landmarks) he or she uses for location awareness and wayfinding. Moreover, we analyze the role of context in this dynamics, i.e., where and when a driver accesses location information from the system, the external supports and the surrounding environment. We present the findings that emerged from 12 interviews augmented by in-car observations within the community of taxi drivers of the city of Barcelona, Spain. This community forms a massive population of early adopters of in-car navigation systems with a strong past practice of relying on mobile technologies and maps to support their work.

Accepted: Leveraging Explicitly Disclosed Location Information to Understand Tourist Dynamics: A Case Study

My paper “Leveraging Explicitly Disclosed Location Information to Understand Tourist Dynamics: A Case Study”, co-authored with Josep Blat, Filippo Dal Fiore and Carlo Ratti, has been accepted for publication in the Journal of Location Based Services. The abstract goes as follows:

In recent years, the large deployment of mobile devices has led to a massive increase in the volume of records of where people have been and when they were there. The analysis of these spatio-temporal data can supply high-level human behavior information valuable to urban planners, local authorities, and designer of location-based services. In this paper, we describe our approach to collect and analyze the history of physical presence of tourists from the digital footprints they publicly disclose on the web. Our work takes place in the Province of Florence in Italy, where the insights on the visitors’ flows and on the nationalities of the tourists who do not sleep in town has been limited to information from survey-based hotel and museums frequentation. In fact, most local authorities in the world must face this dearth of data on tourist dynamics. In this case study, we used a corpus of geographically referenced photos taken in the province by 4280 photographers over a period of 2 years. Based on the disclosure of the location of the photos, we design geovisualizations to reveal the tourist concentration and spatio-temporal flows. Our initial results provide insights on the density of tourists, the points of interests they visit as well as the most common trajectories they follow.

The reviews validate the direction of my theis. They ask me to explore how the insights insight gained from this project can be transferred to other user groups and compare the outcome with the available tourist services. They propose to continue exploring the issues around the quality of the data (i.e. how to reduce the uncerntainty in a bit detailed manner). Finally, I make a case that the visualization validate my hypothesis, but I could also point out the anomalies or unexpected behavior patterns (journalists somehow requested similar outcomes). And, yeah, not to forget the encouraging comment… “This is an excellent paper, covering a very timely and interesting topic“.

Data flow, from data recording, retrieving, storing to the visualizations.

Life in the Real-time City: Mobile Telephones and Urban Metabolism

Townsend, A. M. (2000). Life in the real-time city: mobile telephones and urban metabolism. Journal of Urban Technology, 7(2):85–104.
Back in 2000, Anthony Townsend wrote Life in the real-time city: mobile telephones and urban metabolism, an article that argues that new mobile communication systems are fundamentally rewriting the spatial and temporal constraints of all manners of human communications. As signs of this radical change, accessibility becomes more important than mobility and mobile phones increasingly add an element of uncertainty about physical location to our urban interactions. For instance, as many as one-fifth of cell phones users lie about their location when talking on a mobile phone. “For urban planning, it might mean that the city will change far faster than the ability to understand it from a centralized perspective, let alone formulate plans and policies that will have the desired outcomes”.

As decision-making and management of everyday life is increasingly decentralized, the complexity of these systems become greater and therefore less predictable. In parallel, this decentralization creates myriad new interactions and potential interactions between individuals that is dramatically speeding the metabolism of urban systems, increasing capacity and efficiency.The “real-time city” in which system conditions can be monitored and reacted to instantaneously, has arrived. [...] Real-time systems are defined by an ability to constantly monitor environmental conditions vital to the operation of the system.

In fact without efforts to develop new knowledge and tools for understanding the implications of these new technologies, city planners run the risk of losing touch with the reality of city streets.. Townsend takes an urbanist’s perspective on the application of new communication technologies within cities by their inhabitants (i.e. how do they reshape basic aspects of urban life). However contrary to traditional urban planning, which often assigns agency to a city as a unit (e.g. the city is busy, the city in unfriendly), there are tools for understanding complex systems like cities as consequences of many interactions of individuals. Yet, these tools must go beyond the classical approaches taken in urban planning “the widespread bit-by-bit reconstruction of cities is going largely unnoticed by planners accustomed to visualizing cities through aerial photographs“. In consequence, individuals must become the unit of analysis instead of the institution, neighborhood, city or region. These types of new insights can be gained from interpretive methods such as ethnography (e.g. Kevin Lynch’s The Image of the City) or a psychoanalysts approach. Then the significance of individual-level technological interventions on larger-scale social systems such as cities could be simulated through agent-based modeling.

Also blogged by Nicolas in Increasing pace of interactions in our cities.

Relation to my thesis: This text refers to some pieces of my works. First, similarly to Antoine Picon’s suggestions last week, Townsend stresses the focus on individual interactions (micro events) that make the city. There is also a reference to some sort of glocalization of the city generated by the telephone and mobile phones (decentralizations in urban sprawl and intensification of the center). Second, there is a practical discussion on how taxi driver’s archaic profession was transformed by mobile phones. “The mobile phone permits dynamic reallocation of the taxi system’s resources, resulting in less wasted time searching for fares“. Something that I can argue with my taxi driver study and the importance of satnav not only to improve the efficiency, but also to decrease the stress (improve the quality of life). Third, there is a reference that mobile technologies add uncertainty to our urban interactions (CatchBob!). Finally, this text revives agent-based modeling as a potential output of my thesis.

Abstract Accepted for Situating Sat Nav: Questioning the TomTom Effect

In April of next year, I will attend in Boston the AAG meeting and participate to a session on “Situating Sat Nav: Questioning the TomTom Effect“. Organized by Chris Perkins and Martin Dodge, it aims to address the social effects, cultural meanings and political economy of in-car satellite navigation. I will be in the middle of a spectacular line-up:

Session One

Amy Propen: The Use of Sat Nav Systems: An Empowering Cultural Practice or Portentous of a Lost Geographical Imagination?
Don Cooke: The TomTom Effect: Industry Point of View
Allan Brimicombe and Chao Li: Sat Nav: Rising theft of a geo-engineered must-have.
Tristan Thielmann: Navigation becomes travel scouting: The augmented space of car navigation systems
Caren Kaplan: Precision Targets: Consumer Subjects, Militarization, and the Politics of Location.

Session Two

Fabien Girardin: The co-evolution of taxi drivers and their in-car navigation systems
Georg Gartner: Restrictions in mental representations of the world as a result of relying upon navigation systems
Jonathan Raper: The mistakes that satnavs make (and what they don’t know)
Alexander Klippel: Can we afford to provide cognitively inadequate wayfinding assistance?
Discussant: David M Mark

The abstract of my paper entitled “The co-evolution of taxi drivers and their in-car navigation systems” goes as follow:

In the recent years, the massive use of in-car navigation systems has symbolized the emergence of location-based services for wayfinding. This market success creates the opportunity to learn from a real-world use of present location-aware systems in order to inform the design of future applications. In that context, we are using an ethnomethodological approach to study the different ways taxi drivers rely on their navigation system. First, this work focuses on describing how location technologies impacted the wayfinding practices and similarly how the practice influences the appropriation of navigation systems. This co-evolution starts from the acquisition and setup of a navigation system to mastering the system shortcomings and limitations. Second, we study the criteria that steer a driver in selecting among the different modes of a navigation system and the other artifacts and tools (e.g. maps, street directories, landmarks) he or she uses for location awareness and wayfinding. Moreover, we are analyzing the role of context in this dynamic. That is where and when a driver accesses location information from the system, the external supports and the surrounding environment. We are currently collecting data from 20 semi-structured interviews each augmented by in-car observations of 1-hour ride. The study concentrates on the taxi drivers of the city of Barcelona, Spain. This community forms a massive population of early adopters of in-car navigation systems with a strong past practice of relying on mobile technologies and maps to support their work.

Relation to my thesis: I can’t imagine a better set of people to receive feedback on my taxi driver study.

Presentations at the 4th International Symposium on LBS and TeleCartography

I am in Hong-Kong for the 4th International Symposium on LBS and TeleCartography where I introduced two different works in the Mobile Users Analysis track. First I presented my paper “Understanding of Tourist Dynamics from Explicitly Disclosed Location Information” that describes the early results of the Tracing the Visitor’s Eye project based with data collected in the Province of Florence. I intended to communicate the complementary perspective new types of digital footprints can bring to mobility, urban and travel studies. The content of other presentations in the session (mainly Ahas Rein‘s Mobile Positioning: New Perspective in GIS and Geographical Studies. Ahas chairs an upcoming workshop on social positioning method) that are based GSM network data, helped situate the originality of my approach based on act of communications “I was here” instead of passive, implicit mobility data. It means also no issues of scalability, infrastructure and negotiations with operators. I suggested the idea the explicitly disclosed location data can help inform the design of LBS (e.g. help define area of attention of people, the area of influence of objects, and the granularity of information). Finally, of course, I mentioned the feedback loop generated by people’s past interactions with the urban environment and infrastructure that become recommendations and impact the perception of the space.

Understanding of Tourist Dynamics from Explicitly Disclosed Location Information (slides in PDF)

Later, I presented (on behalf of the WikiCity team) the main concepts and design of the MIT SENSEable City Lab current project WikiCity. Without getting into the technical details, I stressed the importance of developing a real-time mapping of city dynamics for people to become actuators and prime actors of the cityspace. The scenarios of WikiCity is based on the fusion of 3 elements agents (individuals, companies, local authorities…), the environment (architecture, infrastructure, climate…) and technology features (opportunities and limitation positioning and sensing technologies. A main challenge is to provide a common format for interchange of realtime location-based data and to communicate the information to multi-modal interfaces (close to the person such as mobile/fixed devices, embedded in the infrastructure, vehicles (public transport, individual cars).

WikiCity: How can a city perform as an open-source real-time system (slides in PDF)

Urban Informatics: Community Integration and Implementation

A book in the making, Urban Informatics: Community Integration and Implementation will include contributions from (among many others) Anthony Townsend, Carlo Ratti, Adam Greenfield, Paul Dourish, Genevieve Bell, Vassilis Kostakos, Christian Nold, Eric Paulos. Some of the contributions come from the presentations given at the Digital Cities 5 workshop at the 3rd International Conference on Communities and Technologies 2007. It is edited by Marcus Foth.

Foth, M. (Ed.) (2008, forthcoming). Urban Informatics: Community Integration and Implementation. Hershey, PA: Information Science Reference, IGI Global. Contracted 28 Jan 2007.

Journal of Location-Based Services

The first issue of the Journal of Location-Based Services is now online. It includes a very complete editorial lead article with A critical evaluation of location based services and their potential written by Jonathan Raper. There are several more issues of the journal queueing up to get into print, but the editors are still looking urgently for new LBS articles.

The call for paper, states a wide scope of interest:

Published research will span the field from location-based computing and next-generation interfaces through telecom location architectures to business models and the social implications of this technology. The diversity of content echoes the extended nature of the chain of players required to make location-based services a reality. Hence the journal’s aim is to bridge the research undertaken in industry and academia and promote communication amongst all in this diverse and rapidly growing sector

Relation to my thesis: a very fine place to publish.