M Haklay

OpenStreetMap: User-Generated Street Maps

The OpenStreetMap project is a knowledge collective that provides user-generated street maps. OSM follows the peer production model that created Wikipedia; its aim is to create a set of map data thats free to use, editable, and licensed under new copyright schemes. A considerable number of contributors edit the world map collaboratively using the OSM technical infrastructure, and a core group, estimated at approximately 40 volunteers, dedicate their time to creating and improving OSMs infrastructure, including maintaining the server, writing the core software that handles the transactions with the server, and creating cartographical outputs. Theres also a growing community of software developers who develop software tools to make OSM data available for further use across different application domains, software platforms, and hardware devices. The OSM projects hub is the main OSM Web site.

How Good is Volunteered Geographical Information? A Comparative Study of OpenStreetMap and Ordnance Survey Datasets

Within the framework of Web 2.0 mapping applications, the most striking example of a geographical application is the OpenStreetMap (OSM) project. OSM aims to create a free digital map of the world and is implemented through the engagement of participants in a mode similar to software development in Open Source projects. The information is collected by many participants, collated on a central database, and distributed in multiple digital formats through the World Wide Web. This type of information was termed ‘Volunteered Geographical Information’ (VGI) by Goodchild, 2007. However, to date there has been no systematic analysis of the quality of VGI. This study aims to fill this gap by analysing OSM information. The examination focuses on analysis of its quality through a comparison with Ordnance Survey (OS) datasets. The analysis focuses on London and England, since OSM started in London in August 2004 and therefore the study of these geographies provides the best understanding of the achievements and difficulties of VGI. The analysis shows that OSM information can be fairly accurate: on average within about 6 m of the position recorded by the OS, and with approximately 80% overlap of motorway objects between the two datasets. In the space of four years, OSM has captured about 29% of the area of England, of which approximately 24% are digitised lines without a complete set of attributes. The paper concludes with a discussion of the implications of the findings to the study of VGI as well as suggesting future research directions.

How Many Volunteers Does it Take to Map an Area Well? The Validity of Linus' Law to Volunteered Geographic Information

Abstract title/> In the area of volunteered geographical information (VGI), the issue of spatial data quality is a clear challenge. The data that are contributed to VGI projects do not comply with standard spatial data quality assurance procedures, and the contributors operate without central coordination and strict data collection frameworks. However, similar to the area of open source software development, it is suggested that the data hold an intrinsic quality assurance measure through the analysis of the number of contributors who have worked on a given spatial unit. The assumption that as the number of contributors increases so does the quality is known as ‘Linus’ Law’ within the open source community. This paper describes three studies that were carried out to evaluate this hypothesis for VGI using the OpenStreetMap dataset, showing that this rule indeed applies in the case of positional accuracy.

Web-based GIS for collaborative planning and public participation: an application to the strategic planning of wind farm sites.

Spatial planning typically involves multiple stakeholders. To any specific planning problem, stakeholders often bring different levels of knowledge about the components of the problem and make assumptions, reflecting their individual experiences, that yield conflicting views about desirable planning outcomes. Consequently, stakeholders need to learn about the likely outcomes that result from their stated preferences; this learning can be supported through enhanced access to information, increased public participation in spatial decision-making and support for distributed collaboration amongst planners, stakeholders and the public. This paper presents a conceptual system framework for web-based GIS that supports public participation in collaborative planning. The framework combines an information area, a Multi-Criteria Spatial Decision Support System (MC-SDSS) and an argumentation map to support distributed and asynchronous collaboration in spatial planning. After analysing the novel aspects of this framework, the paper describes its implementation, as a proof of concept, in a system for Web-based Participatory Wind Energy Planning (WePWEP). Details are provided on the specific implementation of each of WePWEPs four tiers, including technical and structural aspects. Throughout the paper, particular emphasis is placed on the need to support user learning throughout the planning process.

Usability evaluation and PPGIS: towards a user-centred design approach

Public Participation GIS (PPGIS) is a field of research that, among other things, focuses on the use of GIS by non-experts and occasional users. These users tend to have a diverse range of computer literacy, world views, cultural backgrounds and knowledge. These aspects require that the systems used within PPGIS are accessible and easy to use. Human-Computer Interaction (HCI) and the related usability evaluation techniques focus on how to make computer systems more accessible, while focusing on user needs and requirements. Thus, the synergy between PPGIS and HCI seems natural. In this paper, we discuss the aspects of this synergy, building on our experience from three workshops. We demonstrate how usability evaluation can contribute to PPGIS research, and how PPGIS research can contribute to the HCI aspects of GIS in general. We conclude this paper with a call for a user-centred design approach to PPGIS projects.

Agent-based models and individualism: is the world agent-based?

Agent-based models (ABMs) are an increasingly popular tool in the social sciences. This trend seems likely to continue, so that they will become widely used in geography and in urban and regional planning. We present an overview of examples of these models in the life sciences, economics, planning, sociology, and archaeology. We conclude that ABMs strongly tend towards an individualist view of the social world. This point is reinforced by closer consideration of particular examples. This discussion pays attention to the inadequacy of an individualist model of society with reference to debates in social theory. We argue that because models are closed representations of an open world it is important that institutions and other social structures be explicitly included, or that their omission be explained. A tentative explanation for the bias of ABMs is offered, based on an examination of early research in artificial intelligence and distributed artificial intelligence from which disciplines the approach is derived. Some implications of these findings are discussed. We indicate some useful research directions which are beginning to tackle the individualism issue directly. We further note that the underlying assumptions of ABMs are often hidden in the implementation details. We conclude that such models must be subject to critical examination of their assumptions, and that model builders should engage with social theory if the approach is to realise its full potential.

Neogeography and the delusion of democratisation

Within the academic and popular discussion of neogeography, it is routinely argued that the process of producing and using geographical information has been fundamentally democratised. Neogeography, in contrast to ‘established geography’, especially uses the argument that it is for anyone, anywhere, and anytime. Similar arguments have been used to praise the growth in Web GIS since the mid-1990s and seem to be persistent in the conceptualisation of these technologies. However, what is the nature of this democracy, and to what extent do the technologies that are used in neogeography fulfil this democratisation promise? In this contribution the framework offered by Andrew Feenberg in his critical theory of technology, and especially his call for ‘deep democratisation’, is used to provide a critique of these assertions of the nature of neogeography. The analysis shows that, unlike early critical GIS and the literature on participatory GIS, the analysis of neogeography adopted an instrumentalist interpretation of the technology and its applications. This view claims that technology is value free and that there is a separation between means and ends. This type of argument ignores and disguises the values that are integrated inexorably in advanced technologies. Once the values are exposed and discussed, neogeography becomes far less exciting and transformative. It becomes clear that there is a separation between a technological elite and a wider group of uninformed, labouring participants who are not empowered through the use of the technology. There are also multiple obstacles that limit the democratic potential of neogeography. The analysis progresses by considering the hierarchy of hacking, understood here as the ability to alter and change the meaning and use of a specific technological system. This hierarchy further explains the democratisation potentialities and limits of neogeography. Because of the reduced barriers, neogeography does offer some increased level of democratisation but, to fulfil this potential, it requires careful implementation that takes into account social and political aspects.

So go downtown: simulating pedestrian movement in town centres

Pedestrian movement models have been developed since the 1970s. A review of the literature shows that such models have been developed to explain and predict macro, meso, and micro movement patterns. However, recent developments in modelling techniques, and especially advances in agent-based simulation, open up the possibility of developing integrative and complex models which use existing models as ‘building blocks’. In this paper we describe such integrative, modular approach to simulating pedestrian movement behaviour. The STREETS model, developed by using Swarm and GIS, is an agent-based model that focuses on the simulation of the behavioural aspects of pedestrian movement. The modular structure of the simulation is described in detail. This is followed by a discussion of the lessons learned from the development of STREETS, especially the advantages of adopting a modular approach and other aspects of using the agent-based paradigm for modelling.

Assessing Data Completeness of VGI through an Automated Matching Procedure for Linear Data

New, free and fast growing spatial data sources have appeared online, based on VolunteeredGeographic Information (VGI). OpenStreetMap (OSM) is maybe the most representative project of this trend. Its increasing popularity and density urges researchers on studying its data quality. When this includes comparison with a reference dataset, data matching is necessary for the comparison to be meaningful, usually performed manually at data preparation stage. We propose an automated matching method specifically designed for VGI, based on a multi-stage approach that combines geometric and attribute constraints. We apply it on OSM dataset to compare it against official data from Ordnance Survey. We then show how the results can be used to evaluate data completeness of OSM.

Usability Engineering for GIS: Learning from a Screenshot

Abstract In this paper, the focus is on the concept of Usability Engineering for GIS – a set of techniques and methods that are especially suitable for evaluating the usability of GIS applications – which can be deployed as part of the development process. To demonstrate how the framework of Usability Engineering for GIS can be used in reality, a screenshot study is described. Users were asked to provide a screenshot of their GIS during their working day. The study shows how a simple technique can help in understanding the way GIS is used in situ.