Project Sidewalk: a Web-Based Crowdsourcing Tool for Collecting Sidewalk Accessibility Data at Scale Manaswi SAHA

Total Page:16

File Type:pdf, Size:1020Kb

Project Sidewalk: a Web-Based Crowdsourcing Tool for Collecting Sidewalk Accessibility Data at Scale Manaswi SAHA Singapore Management University Institutional Knowledge at Singapore Management University Research Collection School Of Information Systems School of Information Systems 5-2019 Project Sidewalk: A Web-based crowdsourcing tool for collecting sidewalk accessibility data at scale Manaswi SAHA Michael SAUGSTAD Hanuma MADDALI Aileen ZENG Ryan HOLLAND See next page for additional authors DOI: https://doi.org/10.1145/3290605.3300292 Follow this and additional works at: https://ink.library.smu.edu.sg/sis_research Part of the Databases and Information Systems Commons, and the Geographic Information Sciences Commons Citation SAHA, Manaswi; SAUGSTAD, Michael; MADDALI, Hanuma; ZENG, Aileen; HOLLAND, Ryan; BOWER, Steven; DASH, Aditya; CHEN, Sage; Li, Anthony; HARA, Kotaro; and FROEHLICH, Jon. Project Sidewalk: A Web-based crowdsourcing tool for collecting sidewalk accessibility data at scale. (2019). CHI '19: Proceedings of the 2019 CHI Conference on Human Factors in Computing Systems, Glasgow, Scotland, May 4-9. 62:1-14. Research Collection School Of Information Systems. Available at: https://ink.library.smu.edu.sg/sis_research/4399 This Conference Proceeding Article is brought to you for free and open access by the School of Information Systems at Institutional Knowledge at Singapore Management University. It has been accepted for inclusion in Research Collection School Of Information Systems by an authorized administrator of Institutional Knowledge at Singapore Management University. For more information, please email [email protected]. Author Manaswi SAHA, Michael SAUGSTAD, Hanuma MADDALI, Aileen ZENG, Ryan HOLLAND, Steven BOWER, Aditya DASH, Sage CHEN, Anthony Li, Kotaro HARA, and Jon FROEHLICH This conference proceeding article is available at Institutional Knowledge at Singapore Management University: https://ink.library.smu.edu.sg/sis_research/4399 Project Sidewalk: A Web-based Crowdsourcing Tool for Collecting Sidewalk Accessibility Data at Scale 1Manaswi Saha, 1Michael Saugstad, 2Hanuma Teja Maddali, 1Aileen Zeng, 3Ryan Holland, 2Steven Bower, 2Aditya Dash, 4Sage Chen, 2Anthony Li, 5Kotaro Hara, 1Jon Froehlich 1University of Washington; 2University of Maryland, College Park; 3Montgomery Blair High School; 4University of Michigan; 5Singapore Management University {manaswi,saugstad,aileenz,jonf}@cs.washington.edu Figure 1: In an 18-month deployment study of Project Sidewalk, we collected 205,385 sidewalk accessibility labels, including curb ramps, missing curb ramps, sidewalk obstacles, and surface problems. Each dot above represents a geo-located label rendered at 50% translucency. Try out the tool at http://projectsidewalk.io. ABSTRACT demonstrate the potential of virtually auditing urban accessi- We introduce Project Sidewalk, a new web-based tool that bility and highlight tradeoffs between scalability and quality enables online crowdworkers to remotely label pedestrian- compared to traditional approaches. related accessibility problems by virtually walking through CCS CONCEPTS city streets in Google Street View. To train, engage, and sus- tain users, we apply basic game design principles such as • Human-centered computing → Accessibility systems interactive onboarding, mission-based tasks, and progress and tools; Interactive systems and tools; • Information dashboards. In an 18-month deployment study, 797 online systems → Crowdsourcing. users contributed 205,385 labels and audited 2,941 miles of KEYWORDS Washington DC streets. We compare behavioral and label- ing quality differences between paid crowdworkers and vol- Crowdsourcing, accessibility, mobility impairments, GIS unteers, investigate the effects of label type, label severity, ACM Reference Format: and majority vote on accuracy, and analyze common label- Manaswi Saha, Michael Saugstad, Hanuma Teja Maddali, Aileen ing errors. To complement these findings, we report on an Zeng, Ryan Holland, Steven Bower, Aditya Dash, Sage Chen, An- interview study with three key stakeholder groups (N=14) thony Li, Kotaro Hara, Jon Froehlich. 2019. Project Sidewalk: A soliciting reactions to our tool and methods. Our findings Web-based Crowdsourcing Tool for Collecting Sidewalk Accessibil- ity Data at Scale. In CHI Conference on Human Factors in Computing Systems Proceedings (CHI 2019), May 4–9, 2019, Glasgow, Scotland UK. ACM, New York, NY, USA, 14 pages. https://doi.org/10.1145/ 3290605.3300292 Permission to make digital or hard copies of all or part of this work for personal or classroom use is granted without fee provided that copies 1 INTRODUCTION are not made or distributed for profit or commercial advantage and that copies bear this notice and the full citation on the first page. Copyrights Geographic Information Systems (GIS) such as Google Maps, for components of this work owned by others than the author(s) must Waze, and Yelp have transformed the way people travel be honored. Abstracting with credit is permitted. To copy otherwise, or and access information about the physical world. While republish, to post on servers or to redistribute to lists, requires prior specific these systems contain terabytes of data about road networks permission and/or a fee. Request permissions from [email protected]. and points of interest (POIs), their information about physi- CHI 2019, May 4–9, 2019, Glasgow, Scotland UK cal accessibility is commensurately poor. GIS websites like © 2019 Copyright held by the owner/author(s). Publication rights licensed to ACM. Axsmap.com, Wheelmap.org, and AccessTogether.org aim to ACM ISBN 978-1-4503-5970-2/19/05...$15.00 address this problem by collecting location-based accessibil- https://doi.org/10.1145/3290605.3300292 ity information provided by volunteers (i.e., crowdsourcing). CHI 2019, May 4–9, 2019, Glasgow, Scotland UK M. Saha et al. While these efforts are important and commendable, their study, paid workers also significantly outperformed regis- value propositions are intrinsically tied to the amount and tered and anonymous volunteers in finding accessibility prob- quality of data they collect. In a recent review of accessibility- lems (recall=68% vs. 61% and 49%, respectively) but precision oriented GIS sites, Ding et al. [15] found that most suffered was roughly equivalent for all groups (~70%). Our findings from serious data sparseness issues. For example, only 1.6% also show that the number of found issues significantly in- of the Wheelmap POIs had data entered on accessibility. One creases with the number of labelers per street—with five key limiting factor is the reliance on local populations with labelers, recall rose from 68% to 92%. physical experience of a place for data collection. While local To complement these findings, our interview study asked users who report data are likely to be reliable, the dependence about perceptions of and experiences with urban accessibil- on in situ reporting dramatically limits scalability—both who ity and solicited reactions to Project Sidewalk and the idea of can supply data and how much data they can easily supply. crowdsourcing accessibility in general. All three stakeholder In contrast, we are exploring a different approach embod- groups were positive: while government officials emphasized ied in a new interactive tool called Project Sidewalk (Figure 2), cost-savings and civic engagement, the MI and caregiver which enables online crowdworkers to contribute physical- groups focused more on personal utility and enhanced inde- world accessibility information by virtually walking through pendence. Key concerns also arose, including data reliability, city streets in Google Street View (GSV)—similar to a first- maintenance, and, for the MI participants, whether labels person video game. Rather than pulling solely from local properly reflected their accessibility challenges (the latter populations, our potential pool of users scales to anyone echoes findings from [24]). with an Internet connection and a web browser. Project Side- In summary, the contributions of this paper include: (i) walk extends previous work in streetscape imagery auditing Project Sidewalk, a novel web-based virtual auditing tool tools like Canvas [4], Spotlight [7], BusStop CSI [23], and for collecting urban accessibility data at scale; (ii) results Tohme [26], all which demonstrate the feasibility of virtual from an 18-month deployment and complementary data val- auditing and, crucially, that virtual audit data has high con- idation study exploring key behavioral and labeling quality cordance with traditional physical audits. However, this past differences between volunteer and paid crowdworkers; (iii) work has focused on small spatial regions, relied on special- findings from semi-structured interviews with three stake- ized user populations such as public health researchers [4, 7] holder groups soliciting reactions to Project Sidewalk and and paid crowdworkers [23, 26], and has not been publicly identifying key concerns and design suggestions; (iv) and our deployed. large, open-source sidewalk accessibility dataset1, which we In this paper, we present an 18-month deployment study believe is the largest of its kind. By scaling up data collection of Project Sidewalk in Washington DC. In total, 797 users methods for sidewalk accessibility, our overarching aim is contributed 205,385 geo-located accessibility labels and vir- to enable the development of new accessibility-aware map- tually audited the entirety of Washington DC (1,075 miles of ping tools (e.g., [24, 32]), provide increased transparency and city streets; see Figure 2).
Recommended publications
  • Geohack - Boroo Gold Mine
    GeoHack - Boroo Gold Mine DMS 48° 44′ 45″ N, 106° 10′ 10″ E Decim al 48.745833, 106.169444 Geo URI geo:48.745833,106.169444 UTM 48U 585970 5399862 More formats... Type landmark Region MN Article Boroo Gold Mine (edit | report inaccu racies) Contents: Global services · Local services · Photos · Wikipedia articles · Other Popular: Bing Maps Google Maps Google Earth OpenStreetMap Global/Trans-national services Wikimedia maps Service Map Satellite More JavaScript disabled or out of map range. ACME Mapper Map Satellite Topo, Terrain, Mapnik Apple Maps (Apple devices Map Satellite only) Bing Maps Map Aerial Bird's Eye Blue Marble Satellite Night Lights Navigator Copernix Map Satellite Fourmilab Satellite GeaBios Satellite GeoNames Satellite Text (XML) Google Earthnote Open w/ meta data Terrain, Street View, Earth Map Satellite Google Maps Timelapse GPS Visualizer Map Satellite Topo, Drawing Utility HERE Map Satellite Terrain MapQuest Map Satellite NASA World Open Wind more maps, Nominatim OpenStreetMap Map (reverse geocoding), OpenStreetBrowser Sentinel-2 Open maps.vlasenko.net Old Soviet Map Waze Map Editor, App: Open, Navigate Wikimapia Map Satellite + old places WikiMiniAtlas Map Yandex.Maps Map Satellite Zoom Earth Satellite Photos Service Aspect WikiMap (+Wikipedia), osm-gadget-leaflet Commons map (+Wikipedia) Flickr Map, Listing Loc.alize.us Map VirtualGlobetrotting Listing See all regions Wikipedia articles Aspect Link Prepared by Wikidata items — Article on specific latitude/longitude Latitude 48° N and Longitude 106° E — Articles on
    [Show full text]
  • Assessing the Credibility of Volunteered Geographic Information: the Case of Openstreetmap
    ASSESSING THE CREDIBILITY OF VOLUNTEERED GEOGRAPHIC INFORMATION: THE CASE OF OPENSTREETMAP BANI IDHAM MUTTAQIEN February, 2017 SUPERVISORS: Dr. F.O. Ostermann Dr. ir. R.L.G. Lemmens ASSESSING THE CREDIBILITY OF VOLUNTEERED GEOGRAPHIC INFORMATION: THE CASE OF OPENSTREETMAP BANI IDHAM MUTTAQIEN Enschede, The Netherlands, February, 2017 Thesis submitted to the Faculty of Geo-Information Science and Earth Observation of the University of Twente in partial fulfillment of the requirements for the degree of Master of Science in Geo-information Science and Earth Observation. Specialization: Geoinformatics SUPERVISORS: Dr. F.O. Ostermann Dr.ir. R.L.G. Lemmens THESIS ASSESSMENT BOARD: Prof. Dr. M.J. Kraak (Chair) Dr. S. Jirka (External Examiner, 52°North Initiative for Geospatial Open Source Software GmbH) DISCLAIMER This document describes work undertaken as part of a program of study at the Faculty of Geo-Information Science and Earth Observation of the University of Twente. All views and opinions expressed therein remain the sole responsibility of the author, and do not necessarily represent those of the Faculty. ABSTRACT The emerging paradigm of Volunteered Geographic Information (VGI) in the geospatial domain is interesting research since the use of this type of information in a wide range of applications domain has grown extensively. It is important to identify the quality and fitness-of-use of VGI because of non- standardized and crowdsourced data collection process as well as the unknown skill and motivation of the contributors. Assessing the VGI quality against external data source is still debatable due to lack of availability of external data or even uncomparable. Hence, this study proposes the intrinsic measure of quality through the notion of credibility.
    [Show full text]
  • 16 Volunteered Geographic Information
    16 Volunteered Geographic Information Serena Coetzee, South Africa 16.1 Introduction In its early days the World Wide Web contained static read-only information. It soon evolved into an interactive platform, known as Web.2.0, where content is added and updated all the time. Blogging, wikis, video sharing and social media are examples of Web.2.0. This type of content is referred to as user-generated content. Volunteered geographic information (VGI) is a special kind of user-generated content. It refers to geographic information collected and shared voluntarily by the general public. Web.2.0 and associated advances in web mapping technologies have greatly enhanced the abilities to collect, share and interact with geographic information online, leading to VGI. Crowdsourcing is the method of accomplishing a task, such as problem solving or the collection of information, by an open call for contributions. Instead of appointing a person or company to collect information, contributions from individuals are integrated in order to accomplish the task. Contributions are typically made online through an interactive website. Figure 16.1 The OpenStreetMap map page. In the subsequent sub-sections, examples of crowdsourcing and volunteered geographic information establishment and growth of OpenStreetMap have been devices, aerial photography, and other free sources. This are described, namely OpenStreetMap, Tracks4Africa, restrictions on the use or availability of geospatial crowdsourced data is then made available under the the Southern African Bird Atlas Project.2 and Wikimapia. information across much of the world and the advent of Open Database License. The site is supported by the In the additional sub-sections a step-by-step guide to inexpensive portable satellite navigation devices.
    [Show full text]
  • Deriving Incline for Street Networks from Voluntarily Collected GPS Traces
    Methods of Geoinformation Science Institute of Geodesy and Geoinformation Science Faculty VI Planning Building Environment MASTER’S THESIS Deriving incline for street networks from voluntarily collected GPS traces Submitted by: Steffen John Matriculation number: 343372 Email: [email protected] Supervisors: Prof. Dr.-Ing. Marc-O. Löwner (TU Berlin) Dr.-Ing. Stefan Hahmann (Universität Heidelberg) Submission date: 24.07.2015 in cooperation with: GIScience Group Institute of Geography Faculty of Chemistry and Earth Sciences Declaration of Authorship I, Steffen John, declare that this thesis titled, 'Deriving incline for street networks from voluntarily collected GPS traces’ and the work presented in it are my own. I confirm that: This work was done wholly or mainly while in candidature for a research degree at this Uni- versity. Where any part of this thesis has previously been submitted for a degree or any other qualifi- cation at this University or any other institution, this has been clearly stated. Where I have consulted the published work of others, this is always clearly attributed. Where I have quoted from the work of others, the source is always given. With the exception of such quotations, this thesis is entirely my own work. I have acknowledged all main sources of help. Where the thesis is based on work done by myself jointly with others, I have made clear exact- ly what was done by others and what I have contributed myself. Signed: Date: ii Abstract The knowledge of incline is useful for many use-cases in navigation for electricity-powered vehicles, cyclists or mobility-restricted people (e.g.
    [Show full text]
  • India Map with Directions Hd
    India Map With Directions Hd immobilisingSansone is proprioceptive: or pulverising willy-nilly.she intonates Autumnal sunwise and and crenate long herFrankie tuberosities. never tappings Disorienting critically and when trickiest Sloan Darrick overselling prenotify his her cumarin. temporary Maps on or directions for. Mawsynram in the world with india political boundaries, you get your feedback back country to be measur. Some features a map with india to the direction and not available in nainital? Are you wish to. Complete the direction line features a bunch look for the menu will appear here. The direction is it with no space to. I N D I A N O C E A N A Y O F BENGAL N I N D I A States and Union Territories New Delhi Srinagar Shimla Chandigarh Dehradun Jaipur Gandhinagar. It with india can be noted. On Wednesday the storm made landfall on India's eastern coast when wind speeds between 100 and 115 miles per hour. The direction is nepal and sichuan airline have traveled from nasa. Environmental issues for india with compass rose an abundance of northern border with artistic hindu goddess of these cities. Maps depict production and maps service during its landscape with india, and powerful developer tools to that they always reliable crossing could be an informative guide providing a block after day. Old is india with any particular place where many years, mouths of northern and myanmar. 41 Best Map of India With States ideas india map india. Campus Maps and Directions University Information. Google Maps. Read about major cities. Administered zone in india with a simple.
    [Show full text]
  • Shared Data Sources in the Geographical Domain— a Classification Schema and Corresponding Visualization Techniques
    International Journal of Geo-Information Article Shared Data Sources in the Geographical Domain— A Classification Schema and Corresponding Visualization Techniques Franz-Benjamin Mocnik * , Christina Ludwig , A. Yair Grinberger , Clemens Jacobs, Carolin Klonner and Martin Raifer Institute of Geography, Heidelberg University, 69120 Heidelberg, Germany; [email protected] (C.L.); [email protected] (A.Y.G.); [email protected] (C.J.); [email protected] (C.K.); [email protected] (M.R.) * Correspondence: [email protected] Received: 12 March 2019; Accepted: 15 May 2019; Published: 27 May 2019 Abstract: People share data in different ways. Many of them contribute on a voluntary basis, while others are unaware of their contribution. They have differing intentions, collaborate in different ways, and they contribute data about differing aspects. Shared Data Sources have been explored individually in the literature, in particular OpenStreetMap and Twitter, and some types of Shared Data Sources have widely been studied, such as Volunteered Geographic Information (VGI), Ambient Geographic Information (AGI), and Public Participation Geographic Information Systems (PPGIS). A thorough and systematic discussion of Shared Data Sources in their entirety is, however, still missing. For the purpose of establishing such a discussion, we introduce in this article a schema consisting of a number of dimensions for characterizing socially produced, maintained, and used ‘Shared Data Sources,’ as well as corresponding visualization techniques. Both the schema and the visualization techniques allow for a common characterization in order to set individual data sources into context and to identify clusters of Shared Data Sources with common characteristics.
    [Show full text]
  • Arxiv:2009.08188V1 [Cs.CV] 17 Sep 2020 Update
    JOURNAL Deploying machine learning to assist digital humanitarians: making image annotation in OpenStreetMap more efficient John E. Vargas-Mu~noza*, Devis Tuiab, Alexandre X. Falc~aoa a Laboratory of Image Data Science, Institute of Computing, University of Campinas, Campinas, Brazil; b Laboratory of Geo-information Science and Remote Sensing, Wageningen University & Research, the Netherlands ARTICLE HISTORY Compiled September 18, 2020 ABSTRACT This is a preprint of the paper published in the International Journal of Geographical Information Science. The publisher version can be found here: https://doi.org/10.1080/13658816.2020.1814303 Locating populations in rural areas of developing countries has attracted the atten- tion of humanitarian mapping projects since it is important to plan actions that affect vulnerable areas. Recent efforts have tackled this problem as the detection of buildings in aerial images. However, the quality and the amount of rural building an- notated data in open mapping services like OpenStreetMap (OSM) is not sufficient for training accurate models for such detection. Although these methods have the potential of aiding in the update of rural building information, they are not accurate enough to automatically update the rural building maps. In this paper, we explore a human-computer interaction approach and propose an interactive method to sup- port and optimize the work of volunteers in OSM. The user is asked to verify/correct the annotation of selected tiles during several iterations and therefore improving the model with the new annotated data. The experimental results, with simulated and real user annotation corrections, show that the proposed method greatly reduces the amount of data that the volunteers of OSM need to verify/correct.
    [Show full text]
  • Wialon Checklist (.Pdf)
    Wialon | Monitoring System gurtam.com Monitoring panel and unit properties Sensors and counters Dynamically updated unit list Virtual sensors based on any parameter sent from a device Filtering by IMEI, HW type, phone number, name, etc. Calculation table to configure any type of sensors Quick access to unit tooltip and extended information with the Calibration table management/import/export option to copy it Custom intervals, colors, and textual description for each sensor Copy and import/export tool for backup processes and settings sharing Real-time motion sensor support Smart trip detection capabilities Odometer, engine hours, and GPRS traffic counters Special icons for one-click access to basic tracking Sensor value variation notifications functionality (quick report, video, send SMS, etc.) Retranslation of raw and calculated sensor parameters Simple generation of links to share locations and sensor values Unit properties management/export Driving safety monitoring Unit profile and reference book to view/store parameters Editable driving quality criteria (harsh braking and driving, speeding, cornering, etc.) and presets for cars, trucks, and buses for a number of trackers Maintenance Acceleration calculation based on GPS and data from G-sensors Service approach/expiry notifications Sensors to be used as validators and criteria for violations Intervals by days, mileage, and engine hours Charts and the map with highlighted driving events Vehicle maintenance reporting Driver ranking report Maintenance log handling Custom limits or limits
    [Show full text]
  • Using Geographic Information Systems to Increase Citizen Engagement
    Using Geographic Information Systems to Increase Citizen Engagement Sukumar Ganapati Assistant Professor Public Administration Department School of International and Public Affairs College of Arts and Sciences Florida International University E-Government/Technology Series 2 0 1 0 E-GOVERNMENT/TECHNOLOGY SERIES Using Geographic Information Systems to Increase Citizen Engagement Sukumar Ganapati Assistant Professor Public Administration Department School of International and Public Affairs College of Arts and Sciences Florida International University TABLE OF CONTENTS Foreword ..............................................................................................4 Executive Summary ..............................................................................6 Introduction: Evolution of Geographic Information Systems ...............9 First Wave: Desktop GIS ...................................................................9 Second Wave: Web GIS .................................................................10 Third Wave: Geospatial Web 2.0 Platform .....................................11 Citizen-Oriented Geospatial Web 2.0 e-Government Applications ...13 Citizen-Oriented Transit Information ..............................................13 Citizen Relationship Management ..................................................15 Citizen-Volunteered Geographic Information .................................18 Citizen Participation in Planning and Decision Making ................21 The Future of GIS-Enabled Citizen Participation in Decision
    [Show full text]
  • Turkey Openstreetmap Dataset
    Open Geosci. 2019; 11:140–151 Research Article Open Access Mohammed Zia*, Ziyadin Cakir, and Dursun Zafer Seker Turkey OpenStreetMap Dataset - Spatial Analysis of Development and Growth Proxies https://doi.org/10.1515/geo-2019-0012 Received February 1, 2018; accepted April 16, 2018 1 Introduction Abstract: Number of studies covering major data aspects With the ease of online-data generation and dissemination of OpenStreetMap (OSM) for developed cities and coun- by the advent of Web2.0 technology the narrowly-targeted tries are available in scientific literature. However, this goods and services are getting as economically attractive is not the case for developing ones mainly because of and lucrative as mainstream fare [1, 2]. For example, we low data availability in OSM. This study presents a time- now have Whatsapp, Skype, Viber etc. in Telecommunica- series spatial analysis of Turkey OSM dataset, a devel- tion sector, which was predominantly governed by Tele- oping country, between the year 2007 and 2015 to un- com industries for decades. Wikipedia holds a huge pile derstand how the dataset has developed with time and of online free-content and competes with other propri- space. Five different socio-economic factors of the region etary data sources like Encyclopedia Britannica. Recent are tested to find their relationship, if any, with dataset free publication of classified information by WikiLeaks growth. An east-west spatial trend in data density is ob- and OpenLeaks has challenged governments and other na- served within the country. Population Density and Liter- tional intelligence agencies, who were regulating confi- acy Level of the region are found be the factors control- dential information of citizens so far [3].
    [Show full text]
  • Development of an Update Procedure for Authoritative Spatial Data by the Combination with Crowdsourced Information“
    Faculty of Environmental Sciences Institute for Cartography Master Thesis Development of an update procedure for authoritative spa- tial data by the combination with crowdsourced information submitted by Nita Maulia born on 24.11.1985 in Demak submitted for the academic degree of Master of Science (M.Sc.) Submission on 10/09/2018 Supervisors Prof. Dr. Lars Bernard TU Dresden Dr. Rob Lemmens University of Twente Dr. Stefan Wiemann TU Dresden Task Specification i Statement of Authorship Herewith I declare that I am the sole author of the thesis named „Development of an update procedure for authoritative spatial data by the combination with crowdsourced information“ which has been submitted to the study commission of geosciences today. I have fully referenced the ideas and work of others, whether published or unpublished. Literal or analogous citations are clearly marked as such. Dresden, 10/09/2018 Signature ii Abstract The demand for up-to-date spatial data is growing very high in this rapidly changing world. Updating the authoritative spatial data is not always associated with the updating of well-es- tablished existing spatial data, but it can be extended into the additional collection of new specific-themed spatial data. Unfortunately, authorities who produce ‘golden standard’ spatial data cannot fill those needs. Considering the merits that VGI can give to fill the gap between demand and supply in authoritative data update, a conceptual framework for authoritative data update using VGI data is proposed. The advantage of the proposed framework is its flexibilities that includes: customizable quality assessment modules; flexible assembly and placement of the quality modules; flexible workflow starting point; and the flexible weighting factor.
    [Show full text]
  • HANDS-ON WORKSHOP: Openstreetmap Contents
    HANDS-ON WORKSHOP: OpenStreetMap Working with OpenStreetMap Serena Coetzee, edits by Barend Köbben Version 1.1 March 2015 Contents 1. Introduction...............................................................................................................................1 2. Web 2.0 and geographic information.......................................................................................2 3. Familiarizing yourself with OpenStreetMap..........................................................................43 4. Editing OpenStreetMap data................................................................................................108 5. Downloading OpenStreetMap data.....................................................................................1513 References................................................................................................................................ 1715 1. Introduction These exercises are designed as a hands-on workshop in OpenStreetMap with the following objectives: to provide a brief background of Web 2.0 and geographic information to familiarize yourself with OpenStreetMap to add a point of interest to OpenStreetMap to download, edit and upload OpenStreetMap data with QGIS The exercises are designed for users who are familiar with geographic information and geographic information systems and who have experience in browsing the web and interactively using web applications, such as gmail or facebook. © Centre for Geoinformation Science (CGIS), University of Pretoria 2. Web 2.0 and
    [Show full text]