"A rank clock is a device for visualising the changes over time in the ranked order of any set of objects where the ordering is usually from large to small. The size of cities, of firms, the distribution of incomes, and such-like social and economic phenomena display highly ordered distributions. If you rank order these phenomena by size from largest to smallest, the objects follow a power law over much of their size range, or at least follow a log normal distribution which is a power law in the upper tail."
The idea behind the Rank Clock is:
"... despite the fact that such distributions are so regular even through time, when one examines how objects within these distributions change over time, it is quite clear that somehow these systems remain stable at the aggregate level but with objects which composes them shifting quite dramatically from time period to time period. The Rank Clock is a device that shows how such distributions change over time and it is a natural complement to the rank size distribution which is called a Zipf Plot."
Below are some movies of the Rank Clock in action (further details can be found here). The first is an animated rank clock showing how the rank of cities in the USA changed between 1790 and 2000.
Several months ago we (Suchith Anand, Michael Batty, Andrew Crooks, Andrew Hudson-Smith, Mike Jackson, Richard Milton, Jeremy Morley) where commissioned by the UK's Joint Information Systems Committee (JISC) to produce a TechWatch horizon scanning report entitled "Data mash-ups and the future of mapping."
Below is the executive summary of the report:
"The term 'mash-up' refers to websites that weave data from different sources into new Web services. The key to a successful Web service is to gather and use large datasets and harness the scale of the Internet through what is known as network effects. This means that data sources are just as important as the software that 'mashes' them, and one of the most profound pieces of data that a user has at any one time is his or her location. In the past this was a somewhat fuzzy concept, perhaps as vague as a verbal reference to being in a particular shop or café or an actual street address. Recent events, however, have changed this. In the 1990s, President Bill Clinton's policy decision to open up military GPS satellite technology for 'dual-use' (military and civilian) resulted in a whole new generation of location-aware devices. Around the same time, cartography and GIScience were also undergoing dramatic, Internet-induced changes. Traditional, resource intensive processes and established organizations, in both the public and private sectors, were being challenged by new, lightweight methods. The upshot has been that map making, geospatial analysis and related activities are undergoing a process of profound change. New players have entered established markets and disrupted routes to knowledge and, as we have already seen with Web 2.0, newly empowered amateurs are part of these processes. Volunteers are quite literally grabbing a GPS unit and hitting the streets of their local town to help create crowdsourced datasets that are uploaded to both open source and proprietary databases.
The upshot is an evolving landscape which Tim O'Reilly, proponent of Web 2.0 and always ready with a handy moniker, has labelled Where 2.0. Others prefer the GeoWeb, Spatial Data Infrastructure, Location Infrastructure, or perhaps just location based services. Whatever one might call it, there are a number of reasons why its development should be of interest to those in higher and further education. Firstly, since a person's location is such a profound unit of information and of such value to, for example, the process of targeting advertising, there has been considerable investment in Web 2.0-style services that make use of it. Understanding these developments may provide useful insights for how other forms of data might be used. Secondly, education, particularly research, is beginning to realize the huge potential of the data mash-up concept. As Government, too, begins to get involved, it is likely that education will be expected to take advantage of, and indeed come to relish, the new opportunities for working with data.
This TechWatch report describes the context for the changes that are taking place and explains why the education community needs to understand the issues around how to open up data, how to create mash-ups that do not compromise accuracy and quality and how to deal with issues such as privacy and working with commercial and non-profit third parties. It also shows how data mash-ups in education and research are part of an emerging, richer information environment with greater integration of mobile applications, sensor platforms, e-science, mixed reality, and semantic, machine-computable data and speculates on how this is likely to develop in the future."
Anand, S., Batty, M., Crooks, A. T., Hudson-Smith, A., Jackson, M.,
Milton, R. and Morley, J. (2010), Data Mash-ups and the Future of
Mapping. Joint Information Systems Committee (JISC) Technology and Standards Watch (TechWatch) Horizon Scanning report 10_01, Bristol, England. (pdf)
The built environment is a significant factor in many urban processes, yet direct measures of built form are seldom used in geographical studies. Representation and analysis of urban form and function could provide new insights and improve the evidence base for research. So far progress has been slow due to limited data availability, computational demands, and a lack of methods to integrate built environment data with aggregate geographical analysis. Spatial data and computational improvements are overcoming some of these problems, but there remains a need for techniques to process and aggregate urban form data. Here we develop a Built Environment Model of urban function and dwelling type classifications for Greater London, based on detailed topographic and address-based data (sourced from Ordnance Survey MasterMap). The multi-scale approach allows the Built Environment Model to be viewed at fine-scales for local planning contexts, and at city-wide scales for aggregate geographical analysis, allowing an improved understanding of urban processes. This flexibility is illustrated in the two examples, that of urban function and residential type analysis, where both local-scale urban clustering and city-wide trends in density and agglomeration are shown. While we demonstrate the multi-scale Built Environment Model to be a viable approach, a number of accuracy issues are identified, including the limitations of 2D data, inaccuracies in commercial function data and problems with temporal attribution. These limitations currently restrict the more advanced applications of the Built Environment Model.
The full title of the paper and reference is:
Smith, D. A. and Crooks, A. T. (2010), From Buildings to Cities:
Enabling the Multi-Scale Analysis of Urban Form and Function through the
integration of Geographical and Geometric Methods. Centre for Advanced Spatial Analysis (University College London): Working Paper 155, London, England. (pdf)
ENFOLD-ing: Explaining, Modelling and Forecasting Global Dynamics
ENFOLD-ing is a major new multi-discliplinary EPSRC research grant which has been awarded to UCL under the direction of Sir Alan Wilson. Seven UCL departments are involved in the project. Here is a summary of the 5 Research Associate vacancies and 3 PhD studentships:
This post is working with Steven Bishop and Frank Smith from UCL Mathematics. The main purpose is to initiate, develop, design and be responsible for the delivery of a programme of high quality research into the applied mathematics relevant to migration, trade, security and related issues of most interest to the overall aims of the ENFOLD-ing project. Essential skills include substantial knowledge & programming experience in any of the programming languages C#, C++, Java (or evidence of ability to learn new programming languages), a postgraduate qualification in mathematics or a mathematical science related area,and expertise in mathematical modelling and /or complex systems and ability to develop models related to migration, trade, security. For full details and to apply for this job, please review the advert on the UCL HR website.
Research Associate (Trade workstream) Ref: 1132947 Funded for three years in the first instance at Grade 7 spine point 29 (£31,778 including London Weighting)
This post is working with Francesca Medda from the UCL Centre for Transport Studies and Sir Alan Wilson from the Centre for Advanced Spatial Analysis. The main purpose is to develop models of international trade on a global scale and to contribute to the delivery of a global intelligence system to support the overall aims of the ENFOLD-ing project. Essential skills include expertise in mathematical modelling and /or complex systems, expertise in international trade and/or economics and substantial knowledge & programming experience in any of the programming languages C#, C++, Java, or evidence of ability to learn new programming languages. For full details and to apply for this job, please review the advert on the UCL HR website.
This post is primarily working with Pablo Mateos from UCL Geography and Michael Batty from the Centre for Advanced Spatial Analysis. The main purpose is to initiate, develop, design and be responsible for the delivery of a programme of high quality quantitative research into the relevant statistical, geographical and theoretical aspects related to migration analysis. Essential skills include substantial knowledge & programming experience in any of the following programming languages: C#, C++, Java, Python, knowledge and experience of designing, constructing and analysing large databases and a postgraduate qualification in either a quantitative speciality within a social science discipline (such as statistics, geography, economics, sociology, epidemiology/ public health, GIS, spatial analysis) or a science discipline with experience in social science applications (such as computer science, maths, physics, medicine, and any other relevant disciplines).
Research Associate (Security workstream) Ref: 1133143 Funded for five years in the first instance at Grade 7 spine point 29 (£31,778 including London Weighting)
This post is primarily working with Shane Johnson from UCL Jill Dando Institute of Security and Crime Science. The main purpose of the job, under the guidance of the investigators, is to initiate, develop, design and be responsible for the delivery of a programme of high quality research into security and related issues of most interest to the overall aims of the ENFOLD-ing project. Essential skills include expertise in statistical modelling and /or complex systems and ability to develop models related to security and crime, substantial knowledge & programming experience in any of the programming languages C#, C++, Java, Stata, R or evidence of ability to learn new programming languages and knowledge and experience of constructing and manipulating, or of making valuable use of, large databases. For full details and to apply for this job, please review the advert on the UCL HR website.
This post is primarily working with Sir Alan Wilson and Francesca Medda from the UCL Centre for Transport Studies. The main purpose is to initiate, develop, design and be responsible for the delivery of a global intelligence system, and some associated modelling, of most interest to the overall aims of the ENFOLD-ing project; this includes working in and contributing to the ENFOLD-ing team effort. Essential skills include expertise in mathematical modelling and/or complex systems, a postgraduate qualification in an area related to the ENFOLD project, skills in computer visualisation and substantial knowledge & programming experience in any of the programming languages C#, C++, Java, or evidence of ability to learn new programming languages. For full details and to apply for this job, please review the advert on the UCL HR website.
PhD STUDENTSHIPS 3 x PhD studentships are also available linked to the ENFOLD-ing project. The studentship lasting for three years will cover tuition fees at home rate plus standard living expenses of £15,290 per annum. The studentships are linked to the following workstreams:
Trade workstream: Ref: 1133138 The applicants should possess a good honours degree (1st Class or 2:1 minimum) in any of the following disciplines: Economics, Statistics, Physics, Mathematics, Finance, or any related field. Knowledge in econometric and statistical analysis is highly desirable. It is beneficial if applicants have experience in numerical modelling and programming. Full details, including eligibility and how to apply, are available on the UCL HR website.
Security workstream: Ref: 1133195 The applicants should posess: (1) an MSc in a quantitative social science topic within political science, crime science, statistics, geography, economics, sociology, or a relevant discipline. (2) strong motivation to conduct independent research on the field of security, and basic knowledge on contemporary security concerns (3) excellent quantitative research skills in social sciences, including a good command of statistical analysis and programming knowledge of relevant packages (R, SAS, Stata, SPSS) (4) the ability to work independently and take responsibility of a programme of work (5) excellent written communication skills Full details, including eligibility and how to apply, are available on the UCL HR website.
Migration workstream:Ref: 1133333 The applicants should possess a good honours degree (1st Class or 2:1 minimum) in any of the following disciplines: Economics, Statistics, Physics, Mathematics, Finance, or in any social science program with a strong quantitative component within Geography, Sociology, Epidemiology/ Public Health, GIS, Spatial Analysis or any other closely relevant subject area. An MSc in one of these areas or/and knowledge in econometric and statistical analysis is highly desirable. They should also have excellent quantitative research skills in social sciences including a good command of statistical analysis and programming knowledge of relevant packages (R, SAS,SPSS). As well as strong motivation to conduct independent research on the field of migration and basic knowledge of contemporary issues on migration.
Full details, including eligibility and how to apply, are available on the UCL HR website.
CASA at UCL are running a one day conference on 13th April which will feature the work of their group on projects associated with their research funded by various UK research councils. The conference is free but you have to register. It is also the day before the UK’s annual conference on GIS called GISRUK which is on the 14-16th April. This conference is chargeable and details can be got from the CASA conference site.
If you want to go to the one day CASA meeting “Advances in Spatial Analysis & e-Social Science”, then please go to the registration site at:
CASA and the UCL Centre for Transport Studies each have a Research Associate vacancy attached to the SCALE project: (Small Changes leAd to Large Effects) Changing Energy Costs in Transport and Location Policy, funded by the EPSRC.
We just received a copy of Virtual Geographic Environments, the book has contributions by Jack Dangermond, Mike Goodchild, Mike Batty, Hui Lin and many others (including ourselves) and provides a unique guide to the current state of play in GIS and virtual environs.
Andrew Hudson-Smith and myself have contributed a chapter entitled "The Renaissance of Geographic Information: Neogeography, Gaming and Second Life". The abstract for our paper is:
"Web 2.0, specifically The Cloud, GeoWeb and Wikitecture are revolutionising the way in which we present, share and analyse geographic data. In this paper we outline and provide working examples a suite of tools which are detailed below, aimed at developing new applications of GIS and related technologies. GeoVUE is one of seven nodes in the National Centre for e-Social Science whose mission it is to develop web-based technologies for the social and geographical sciences. The Node, based at the Centre for Advanced Spatial Analysis, University College London has developed a suite of free software allowing quick and easy visualisation of geographic data in systems such as Google Maps, Google Earth, Crysis and Second Life.These tools address two issues, firstly that spatial data is still inherently difficult to share and visualise for the non-GIS trained academic or professional and secondly that a geographic data social network has the potential to dramatically open up data sources for both the public and professional geographer. With our applications of GMap Creator, and MapTube to name but two, we detail ways to intelligently visualise and share spatial data. This paper concludes with detailing usage and outreach as well as an insight into how such tools are already providing a significant impact to the outreach of geographic information."
"Virtual geographic environments are essential to using GIS in design. For example, before a design for a city or landscape can be produced, an environment must be created through GIS. Thisbook cover is then fashioned into a form where users have access to it, first to enhance their understanding through exploration, and then to enable them to change various components in the effort to solve problems that can realize better designs. Only now, through the development of virtual city models and through new ways of enabling users to interact with geographic information using new screen technologies, is the point being approached where design is possible.Virtual Geographic Environments, edited by Hui Lin and Michael Batty, collects key papers that define the current momentum in GIS and "virtual geographies." In some sense, such environments are the natural consequence of linking GIS to other technologies that deal with information, design, and service provision, and this will undoubtedly grow as it becomes ever easier to integrate diverse software and data across the Web.The idea that geographic information can be both collected and made available through Web-based services, using Web 2.0 technologies that network many millions of people together, has formed a major research thrust in software development over the last decade.The numerous contributions by leading members of the geospatial community to Virtual Geographic Environments illustrate the cutting edge of GIScience, as well as new applications of GIS with the processing and delivery of geographic information through the Web and handheld devices, forming two major directions to these developments. But the notion that these Web-based systems can be used to collect information of a voluntary kind through methods of crowd sourcing is also an exciting and widely unanticipated development that is driving the field. As these services gain ground, new business models are being invented that merge proprietary and nonproprietary systems and novel ways of integrating diverse software through many different processes of software development from map hacks to open system architectures.Virtual Geographic Environments is published by Science Press, China (www.sciencep.com), 350 pages, hardcover. For more information, contact the responsible editors Peng Shengchao and Guan Yan, Science Press (e-mail: guanyan@mail.sciencep.com)."
Hudson-Smith, A. and Crooks, A. T. (2011), The Renaissance of Geographic Information: Neogeography, Gaming and Second Life, in Lin, H. and Batty, M. (eds.), Virtual Geographic Environments, ESRI Press, Redlands, CA. pp 25-36. (pdf)
A decision to move is never easy but I am about to leave CASA and start working in the Department of Computational Social Science at George Mason University in the USA. Over the last several years at CASA, not only have I learnt a lot and developed my skills in agent-based modelling and GIS, but also made some great friends. The CASA collective of Mike, Alan and Paul have given me much to think about, while the rest of the gang (both past and present, you know who you are!) has made my everyday life fun and challenging.
One thing I will miss is the CASA fish tank and while walking around the National Zoo in DC the other day I thought how lucky the fish in CASA are:
We just finished another part of Agent-Street where agents and avatars can interact with each other. The idea here is to merge iconic and symbolic urban models in a multi-user real time environment.
The movie below shows Agent-Street and how one can download the models we have created by clicking on the model vending machines. By clicking on the vending machines, models can be downloaded and saved. Such vending machines are common features in Second Life and allow users to store objects and scripts in their personal inventory for later use such as rebuilding the models on their own Land or in free sand-boxes. We have been using the Mauve Land for this (SLURL).
In our previous models avatars could only visualise and initiate the models. For example, in the pedestrian evacuation model users could only observe how agents exited the building (in a similar way to professionally developed 3D pedestrian modelling software packages such as STEPS). In this new model, we extend the basic pedestrian evacuation model, so that agents not only consider their environments but also other avatars. In this sense we are not only incorporating iconic and symbolic modelling styles but also adding a further human dimension, moving towards an augmented reality (i.e. as if the agents and the humans were in the same crowd). The movie below shows how pedestrian paths change when avoiding an avatar. The movie shows a how an avatar stationed near the exit impacts on pedestrian egress as agents have to move around it.
Previous posts on our and others work on Second Life can be found by clicking here. We have also set up a website outlining the work in detail (click here) or alternatively if you have a Second Life account this SLurl will take you to the Land, once you teleport to the area, follow the red arrow (beam of red light) into the sky to find Agent-Street. If the models are running slow let us know as we having problems with fish entering our land from a neighbouring island.
"In this paper we analyse the street network of London both in its primary and dual representation. To understand its properties, we consider three idealised models based on a grid, a static random planar graph and a growing random planar graph. Comparing the models and the street network, we find that the streets of London form a self-organising system whose growth is characterised by a strict interaction between the metrical and informational space. In particular, a principle of least effort appears to create a balance between the physical and the mental effort required to navigate the city."
The full reference is:
Masucci, A. P., Smith, D., Crooks, A. T. and Batty, M. (2009) Random Planar Graphs and the London Street Network, Centre for Advanced Spatial Analysis (University College London): Working Paper 146, London, England. (pdf)
Currently at CASA we are exploring ways to simulate various aspects of city life and visualize such models taking advantage of our London database which we are developing along with the advances in graphic card technology and networked communication. We presented some of this work at the AAG last week (click here to download the presentation and here to see the abstract).
We just finished writing a brief paper for the April 2009 issue of Geospatial Today entitled "New Developments in GIS for Urban Planning". The paper basically covers new the tools and techniques being developed at CASA which we are targeting at urban planners. Many of the tools are associated with visualising urban problems and their solutions.
Virtual London within Google Earth
Full Reference:
Batty, M., Hudson-Smith, A., Crooks, A. T., Milton R. and Smith D. (2009) New Developments in GIS for Urban Planning, Geospatial Today, June: 40-43. (pdf).
There is a growing interest and use of virtual worlds for both entertainment and academic research. Worlds such as Second Life and World of Warcraft attract thousands of users and have both virtual and real world economies. Such virtual worlds have come a long way since the original text worlds such as Zork (known as MUDS), they have developed into 3D immersive environments, where users can chat using both voice and text.
Virtual worlds can be broadly broken down into two distinct categories, the first being game focused such as World of Warcraft and Star Wars Galaxies (e.g. MMORGs). The second type being socially focused such as Second Life and Active Worlds (e.g. Massively Multiuser Virtual Environments).
Such virtual worlds have a great potential as sites for research in the social, behavioural, and economic sciences (see Bainbridge (2007), The Scientific Research Potential of Virtual Worlds). Universities are using them to promote themselves and exploring there use for teaching (e.g. Ohio University, see the movie below). While others are using virtual worlds for military applications, such as combat simulation (see movie below) or for studying the spread of epidemics (e.g. Kafai et al., 2007). For the geographer, the ability of people to create their own land and build their own houses leads to the creation of a digital geography and research can be carried out in topics such as of urban sprawl and the development of ghost towns were land and buildings have been abandoned by their original inhabitants (see Dodge and Kitchin, 2001 for more information).
My own interest in virtual worlds arises because they offer a new arena to explore agent-based modeling for the social scientist, they can be viewed as a digital laboratory where real world landscapes (including buildings, roads, terrain) can be imported and explored thus moving away from an artificial laboratory on ones desktop into a more collaborative 3D environment comparable to a real-world laboratory accessible by others, who are able to visualize and discuss issues such as pedestrian egress from buildings in real time or taking one of the examples above, imagine using agents as the enemy within combat simulations.
Examples of agent-based models in virtual worlds include ant foraging (Tectonic 2007, see the movie below) or herding behavior of sheep (Merrick and Maher, 2007). While our own work at CASA explores three simple agent-based models as pedagogic demonstrators and as a “proof-of-concept” (see the movie below), including Conway’s Game of Life, Schelling’s (1978) Segregation model. These models were chosen as they highlight how classical automata styles of models which have inspired a generation of modelers can be created and explored in Second Life. The third model is a prototype pedestrian evacuation model which is more complex than the previous two and highlights how a variety of models that can be created in Second Life and potentially linked to real world places such as football or underground stations. This model relates to the genus of such models of which the social forces model developed and popularised by Helbing and Molnár (1995) is typical.
While virtual worlds offer much potential there are still problems such as the need of land (maybe OpenSim can help here?), deficiencies of the internet (e.g. bandwidth, package delivery etc.), server side delays, limited script sizes, etc. Nevertheless, there is the potential to build realistic cities using real world data, populate such cities with agents and see how the city might evolve over time.
There is also the potential to use evolutionary computation for such modeling. For example the movie below is by Karl Sims and shows results involving simulated Darwinian evolutions of virtual block creatures who are tested for their ability to perform a given task. The successful survive and make offspring for a new population. As this cycle of variation and selection continues, creatures with more and more successful behaviours can emerge (see Evolved Virtual Creatures,1994).
Dodge, M. and Kitchin, R. (2001)Atlas of Cyberspace, Addison-Wesley, London, UK. Kafai, Y.B., Feldon, D., Fields, D., Giang, M. and Quintero, M. (2007) 'Life in the Times of Whypox: A Virtual Epidemic as a Community Event', in Steinfeld, C., Pentland, B., Ackermann, M. and Contractor, N. (eds.), Proceedings of the Third International Conference on Communities and Technology, Springer, New York, pp. 171-190.
Helbing, D. and Molnár, P. (1995) Social Force Model for Pedestrian Dynamics, Physical Review E, 51(5): 4282-4286.
Below is a paper we will be presenting in March at GISRUK 2009. The full reference is:
Crooks, A. T., Hudson-Smith, A., M., Milton, R., and Batty, M. (2009), Crowdsourcing Spatial Surveys and Mapping, in Fairbairn, D. (ed.), Proceedings of the 17th Geographical Information Systems Research UK Conference, Durham University, England, pp 263-269. (pdf)
We thought we would put it on-line, to gauge peoples thoughts about it as it is the product of the crowd. Any comments and suggestions are most welcome.
Why blog about this work? It demonstrates the potential of crowdsourcing peoples opinions to specific questions over space and time both statistically and geographically, such work potentially allows one to crowdsource peoples perceptions on: fear of household burglary, quality of local schools, who would you vote for? etc. Additionally it is the ability to access real time information and use it for a purpose. For example, with the growth in mobile phones with built in GPS (such as the iPhone) if one had enough participants one could use the data for calibrating pedestrian or traffic simulations and therefore help potentially understand human behavoir. Such as peoples daily movement patterns (see urbanTick for such work).
Crowdsourcing Spatial Surveys and Mapping
1. Introduction
This paper presents the potential of linking the GMap Creator software and the MapTube web service to create near-real time spatial surveys. Three different surveys will be presented which map people’s perceptions about certain questions, including the current financial crisis, anti-social behaviour and peoples thoughts on road pricing. Basic results will be highlighted for each and the geodemographic profiles of respondents will be explored. However, before discussing this, the underlying technologies that we use for the creation of the surveys: GMap Creator and MapTube, will be introduced.
1.1. GMap Creator
GMap Creator is a free piece of software that takes a shapefile and enables the creation of thematic layers which can be quickly and easily integrated into Google Maps in a simple ‘point and click’ manner (see Hudson-Smith et al. (under review) for more details). Using GMap Creator, it is possible to overlay pre-rendered thematic tiles on top of street and satellite views of Google Maps, making it possible to show complex areal coverage’s. The purpose of such a tool is to build feature rich cartographic websites that may easily be used and interpreted by individuals who have limited experience of spatial data handling (e.g. www.londonprofiler.org Gibin et al., 2008) rather than for more formal exploratory spatial data analysis.
1.2. MapTube
MapTube (www.maptube.org) combines the generic idea of YouTube where users can share information with the ability of GMap Creator to create thematic maps. MapTube provides a ‘place to put maps’ as we demonstrate in Figure 1, which highlights the most viewed maps currently on the MapTube site. MapTube acts as a portal for geographic data, data is not stored on the site. Every map hosted on MapTube is held on an outside server, and pulled in using the XML file which is automatically created when using GMap Creator. This allows data creators to maintain ownership of the data. MapTube allows one to view and compare different datasets as a series of layers (i.e. mashup) through the Google Map interface. However, we are currently working on an implementation for OpenLayers (see Milton, 2008).
Figure 1.MapTube home page showing the most popular maps.
2: Near Real-Time Spatial Surveys
Not only does MapTube allow people to share and view other people’s maps but it can also be used in more innovative ways. For example, as web surveys are often aspatial (e.g. surveymonkey.com), the ability to combine GMap Creator and MapTube offers a simple solution to build spatial surveys for large areas. Figure 2 shows the process of creating the near real-time maps. Users are asked a series of questions and to enter their postcode so that the results can be geo-coded. This is then sent to a web server, time stamped and stored in a database. Every 30 minutes (however, this can be varied) a script is run to create a new shapefile, compiling all the results from a survey, aggregating them into a spatial units (in this case postcode districts). The shapefile is then passed to GMap Creator along with an XML file containing information including: settings for colour thresholds, maximum level of zoom and the field name of the shapefile for which the map is to be created on. GMap Creator runs creates a series of image tiles which updates the map on MapTube which can then be served back over the internet.
Figure 2. The process of gathering, storing and creation of maps.
What follows are three surveys which map people’s perceptions about certain issues done in association various BBC organisations. For each survey no personal information was collected and participants were reassured that actual locations could not be identified. This was ensured through the use of postcode districts rather than the postcode unit or building address therefore preserving data confidentiality. Used in conjunction with MapTube, it allowed participants and other users to take other information and lay the maps on top of one other.
2.1. Mapping the Credit Crunch
A pilot study was carried out as an experiment to create a mood map of the credit crunch within the United Kingdom in conjunction with BBC Radio 4 iPM show . Based on what is the “singly most significant factor hurting the person the most about the credit crunch”, participants were asked to enter the first part of their postcode (postcode district) so their responses could be geo-tagged along with one of six options to choose from: mortgage or rent, fuel, food prices, holidays, other, or the credit crunch is not affecting me.
Between 26th April and 29th June 2008 there were 23475 responses to the survey with 48.8% of response saying that fuel was most significant factor hurting the person the most about the credit crunch (Figure 3). However there was spatial variation around the country with more respondents within Greater London saying it was either mortgage or rent, or food as shown in Figure 4.
Figure 3. Overall percentages for the Credit Crunch Survey.
Figure 4. Results of the Credit Crunch Survey Focused Around London (Note: the Colour represents the Most Frequent Response in the Postcode District).
2.2. Anti-Social Behaviour in East Anglia
The Credit Crunch Map has since led to BBC Look East, using the system to map peoples perceptions of anti-social behaviour.
Each respondent was asked “what problems do you face where you live?” Respondents had five options: drunken youths, noisy neighbours, boy racers, no problems, great community and no problems. The survey ran between 4th July 2008 and 12th September 2008. During this time 6902 responses were received. Figure 5 shows the overall percentages, with 33.7% saying drunken youths with the other categories broken down relatively evenly between 14 to 18%. Figure 6 maps the responses with drunken youths clustering around urban areas such as Norwich and Newmarket.
Figure 5. Overall Percentages for the Anti-Social Behaviour Survey.
Figure 6. Results of the Anti-Social Behaviour Survey Focused Around East Anglia (Note: the Colour represents the Most Frequent Response in the Postcode District, click here to see the map).
2.3. The Manchester Congestion Charge
There was a proposal for Manchester in introduce a congestion charge zone motorists pay to drive in and out of the city at peak times. The BBC North West Tonight program wanted people's reaction to the proposed Greater Manchester congestion charge, from within the city but also people who drive in from outside the region. As these people don't get a vote but may end up paying the charge (subsequently the people of Manchester said no).
People were asked the following question “If a congestion charge is introduced in Greater Manchester, along with significant investment in public transport, will you:” and then asked to select one of the following options: drive and pay the charge, drive at different times, use public transport/motorbike/bicycle, work or shop elsewhere, or I am not affected by these changes. The survey began on 14th October 2008. By the 10th December 2008, there were 14933 responses with 46.8% saying they would work or shop elsewhere (Figure 7). This online collaboration provided a unique picture of how well the proposal was going down across the north west of England as the map is updated every day (Click here to see the final map).
Figure 7. Overall percentages for the Manchester Congestion Survey.
3. Geodemographic Profiles of Respondents
While we only asked for respondents or their first part of their postcode, many entered their full postcode as can be seen in Table 1. We note that this in not a representative sample but it does provide an opportunity to further investigate who is responding to such surveys. To gain this understanding we use two geodemographic classification schemes. First, the Acorn classification from CACI which categorises neighbourhoods based on multidimensional socio-demographic attributes. The second being the e-Society geodemographic classification (Longley et al., 2008) which categorizes neighbourhoods based on their engagement with new information communication technologies.
For the analysis, index scores was calculated. An index score compares the over or under representation of a specific target variable against a base population (e.g. the national average). Where a score of 100 is the national average, 200 is double the national average and a score of 50 is 50% below the national average. From such analysis it is the middle and upper classes who are over-represented within the surveys as shown in Table 2, this potentially relates to demographics of the readers, listeners, and viewers Radio 4 and the BBC news. The over representation of E-business users in the E-society classification (Table 3) suggest many respondents are answering the questionnaire while at work. Furthermore the geodemographic profiles of responses to individual questions can also be explored as seen in Table 4. Across all demographic groups the biggest concern was fuel.
Table 1. Total Number of Respondents to Surveys and Number Who Entered Their Full Postcode.
Table 2. Index Scores of Respondents by Acorn Category Classification.
Table 3. Index Scores of Respondents by E-Society Group Classification.
Table 4. Percentage of Responses to the Credit Crunch Survey Broken Down by Acorn Category.
4. Discussion
This paper has demonstrated the potential of using GMap Creator and MapTube for near-real time spatial survey thus providing a resource to map the nations opinions to specific questions over space and time both statistically and geographically. The potential of this approach for gathering spatial information is enormous. For example, it could easily be used to gather other information such as fear of household burglary, the quality of primary school education and so on. We consider this in many senses this to be Web 2.0 and Neogeography in action.
However, the geodemographics of the respondents shows there is an inherit bias in who is answering the questions and there is the question to whether or not respondents are influenced by the maps before answering the questions. Further work is to explore how the maps evolve over time, as each response is time stamped and how this relates to news headlines. Additionally, we are currently exploring the geodemographic profiles of each survey in more detail. We have currently re-run the credit crunch with the BBC with slightly different options to the answer.
The question remains the same - "what single factor is hurting you most about the credit crunch?" But we decided to change the categories slightly:Mortgage or rent, Petrol, Food prices, Job security, Utility bills, or Not affected. This survey ran between 5th October 2008 and 3 February 2009 and has now closed. The final map can be viewed here. During this time we received 20,072 responses, which can be broken down as follows (Figure 8): Mortgage or Rent 11.05%, Petrol 4.7%, Food Prices 11.89%, Job Security 27.25%, Utility Bills 21.92%, and Not Affected 23.20%
The Return of the Credit Crunch on the BBC Site
Figure 8: Overall percentages for the Credit Crunch Survey
5. References
Gibin M, Singleton AD, Mateos P, and Longley PA. (2008) Exploratory cartographic visualisation of London using the Google Maps API, Applied Spatial Analysis and Policy 1(2) pp85-97.
Hudson-Smith A, Crooks AT, Gibin M, Milton R, and Batty M (under review) Neogeography and Web 2.0: Concepts, Tools and Applications, Journal of Location Based Services.
Longley PA, Webber R, Li C, (2008) The UK geography of the e-society: a national classification Environment and Planning A 40(2) pp362-382.
Last week CASA hosted a two day workshop showcasing our work along with researchers from the University of Leeds as part of the of the S4 European Spatial Analysis network modelling tour. Over 150 people both from the public and private sector came to the event from all across Europe. The first day of the event was designed to showcase CASA's use of new technologies for mapping and visualizing information about cities and was entitled "Geographic Information in a Web-Based World."
Other talks on the first day explored the use of MapTube and GMapCreator for Crowdsourcing near-real time spatial surveys and understanding crowdsourced geographical information via the analysis of OpenStreetMap. On a more data oriented side, there were talks on exploring urban data collection and mapping, analysing and visualising fine scale urban form and socio-economic datasets. The day concluded with a talk by Andrew Hudson-Smith from Digital Urban on Web 2.0 and neogeography in real and virtual spaces: from geocaching through to Second Life.
The second day of the workshop was entitled "Developments in Urban Models, Simulation and Spatial Analysis" and talks ranged from: rank clocks and scaling in city sizes, geodemographics, retail modelling, the need to capture urban form patterns and processes in agent-based models, pedestrian modelling, consumer behaviour, microsimulation and 3D visualisation and communication of agent-based models.
Click here to see the full program and to download the presentations.
Readers of the blog might have been wondering why I been interested in Second Life (click here to see blog posts on Second Life), and why I been exploring fine scale modelling of the London housing market and what this has to do with GIS and ABM. As part of the CASA seminar series, I was asked to give a talk about some of my work from the last year. The talk was entitled "Modelling Cities: An Approach using Agent-Based Models and GIS' which pulled together these topics. The abstract or the talk is below:
The Agent-based modelling (ABM) paradigm is becoming an increasingly used technique to study cities. It allows us to grow social structures in artificial worlds specifically how a set of micro-specifications are sufficient to generate the macro-phenomena of interest. Until recently many applications of agent-based models exploring urban phenomena have used a regular partition of space (cells) to represent space. While these models have provided valuable insights into urban phenomena especially as they can capture geographic detail, they miss geometric detail. This area is critical to good applications but is barely touched upon in the literature.Geometry (points, lines and polygons), forms the skeleton of cities from streets and buildings, through to parks, rivers, etc. The ability to represent the urban environment as a series of points, lines, and polygons allows for different size features such as houses and roads to be directly incorporated into the modelling process onto which other physical and social attributes can be added. Additionally the inclusion of geometry allows us to make agent-based models more realistic compared to representing the urban environment as a series of discrete regular cells.This presentation introduces ABM, explore how agent-based models coupled loosely with geographic information systems (GIS) can be created through illustrated examples focusing on residential location. These applications directly consider geometry when building these artificial worlds and running the simulations. Furthermore, these models highlight how the inclusion of geometry impacts on simulation results. Problems and challenges with this approach and ABM in general will be identified. To conclude we will argue the need for fine scale and extensive datasets of the built and socio-economic environments to ground such models, along with the need to communicate and visualise agent-based models. To this extent we introduce our detailed housing and built environment database for London, which will be used as a building block for agent-based models associated with London. We then explore how such models might be communicated and shared with others using advances in technology, specifically Web 2.0 and Second Life.
Some people have asked for the slides of the talk, so I have made them available, they can be downloaded from here (28MB). Accompanying these I have also made a movie of the talk which give a sense of dynamics from such models.
Agent-based modelling (ABM) is becoming the dominant paradigm in social simulation due primarily to a worldview that suggests that complex systems emerge from the bottom-up, are highly decentralised, and are composed of a multitude of heterogeneous objects called agents. These agents act with some purpose and their interaction, usually through time and space, generates emergent order, often at higher levels than those at which such agents operate. ABM however raises as many challenges as it seeks to resolve. It is the purpose of this paper to catalogue these challenges and to illustrate them using three somewhat different agent-based models applied to city systems. The seven challenges we pose involve: the purpose for which the model is built, the extent to which the model is rooted in independent theory, the extent to which the model can be replicated, the ways the model might be verified, calibrated and validated, the way model dynamics are represented in terms of agent interactions, the extent to which the model is operational, and the way the model can be communicated and shared with others. Once catalogued, we then illustrate these challenges with a pedestrian model for emergency evacuation in central London, a hypothetical model of residential segregation model tuned to London data, and an agent-based residential location model, for Greater London. The ambiguities posed by this new style of modelling are drawn out as conclusions, and the relative arbitrariness of such modelling highlighted.
Anyone wishing to give us feedback on the article is most welcome.
Full Reference:
Crooks, A.T., Castle, C. J. E., and Batty, M. (2008), Key Challenges in Agent-Based Modelling for Geo-spatial Simulation, Computers, Environment and Urban Systems, 32(6): 417-430. (pdf)
