scholarly journals ASSESSMENT OF COMPLETENESS AND POSITIONAL ACCURACY OF LINEAR FEATURES IN VOLUNTEERED GEOGRAPHIC INFORMATION (VGI)

2015 ◽  
Vol XL-1-W5 ◽  
pp. 169-174
Author(s):  
M. Eshghi ◽  
A. A. Alesheikh
Keyword(s):  
Spatial Data ◽  
Volunteered Geographic Information ◽  
Geographic Information ◽  
Positional Accuracy ◽  
Linear Feature ◽  
Almost All ◽  
Information Collecting ◽  
Correct Data ◽  
Official Data

Recent advances in spatial data collection technologies and online services dramatically increase the contribution of ordinary people to produce, share, and use geographic information. Collecting spatial data as well as disseminating them on the internet by citizens has led to a huge source of spatial data termed as Volunteered Geographic Information (VGI) by Mike Goodchild. Although, VGI has produced previously unavailable data assets, and enriched existing ones. But its quality can be highly variable and challengeable. This presents several challenges to potential end users who are concerned about the validation and the quality assurance of the data which are collected. Almost, all the existing researches are based on how to find accurate VGI data from existing VGI data which consist of a) comparing the VGI data with the accurate official data, or b) in cases that there is no access to correct data; therefore, looking for an alternative way to determine the quality of VGI data is essential, and so forth. In this paper it has been attempt to develop a useful method to reach this goal. In this process, the positional accuracy of linear feature of Iran, Tehran OSM data have been analyzed.

Quality Evaluation of Volunteered Geographic Information

Crowdsourcing ◽  
2019 ◽  
pp. 1173-1201
Author(s):  
Hongyu Zhang ◽  
Jacek Malczewski
Keyword(s):  
Quality Evaluation ◽  
Evaluation Process ◽  
Volunteered Geographic Information ◽  
Geographic Information ◽  
Positional Accuracy ◽  
Product Selection ◽  
Geographic Space ◽  
Large Size

A large amount of crowd-sourced geospatial data have been created in recent years due to the interactivity of Web 2.0 and the availability of Global Positioning System (GPS). This geo-information is typically referred to as volunteered geographic information (VGI). OpenStreetMap (OSM) is a popular VGI platform that allows users to create or edit maps using GPS-enabled devices or aerial imageries. The issue of quality of geo-information generated by OSM has become a trending research topic because of the large size of the dataset and the inapplicability of Linus' Law in a geospatial context. This chapter systematically reviews the quality evaluation process of OSM, and demonstrates a case study of London, Canada for the assessment of completeness, positional accuracy and attribute accuracy. The findings of the quality evaluation can potentially serve as a guide of cartographic product selection and provide a better understanding of the development of OSM quality over geographic space and time.

Quality Evaluation of Volunteered Geographic Information

2017 ◽  
pp. 19-46 ◽  
Author(s):  
Hongyu Zhang ◽  
Jacek Malczewski
Keyword(s):  
Quality Evaluation ◽  
Evaluation Process ◽  
Volunteered Geographic Information ◽  
Geographic Information ◽  
Positional Accuracy ◽  
Product Selection ◽  
Geographic Space ◽  
Large Size

A large amount of crowd-sourced geospatial data have been created in recent years due to the interactivity of Web 2.0 and the availability of Global Positioning System (GPS). This geo-information is typically referred to as volunteered geographic information (VGI). OpenStreetMap (OSM) is a popular VGI platform that allows users to create or edit maps using GPS-enabled devices or aerial imageries. The issue of quality of geo-information generated by OSM has become a trending research topic because of the large size of the dataset and the inapplicability of Linus' Law in a geospatial context. This chapter systematically reviews the quality evaluation process of OSM, and demonstrates a case study of London, Canada for the assessment of completeness, positional accuracy and attribute accuracy. The findings of the quality evaluation can potentially serve as a guide of cartographic product selection and provide a better understanding of the development of OSM quality over geographic space and time.

Quality Assessment of Volunteered Geographic Information for Educational Planning

2017 ◽  
pp. 76-96
Author(s):  
Hafiz Muhammad Muzaffar ◽  
Ali Tahir ◽  
Asmat Ali ◽  
Munir Ahmad ◽  
Gavin McArdle
Keyword(s):  
Spatial Data ◽  
Ground Truth ◽  
Volunteered Geographic Information ◽  
Educational Planning ◽  
Geographic Information ◽  
Public Companies ◽  
Domain Specific ◽  
Route Finding ◽  
Thematic Accuracy

Volunteered Geographic Information is the term used to describe the process of collecting spatial data using a network of volunteers. The approach collects spatial data to build maps which are often freely accessible. The maps and the underlying data can be used by the public, companies and government agencies for a variety of tasks such as route finding. Given that untrained volunteers may collect the spatial data, questions regarding the quality of VGI have been raised. Several studies have emerged to assess the quality (positional, semantic and thematic accuracy) of VGI by comparing the data to ground truth. This approach fails to capture the quality of VGI for domain specific tasks. In this chapter we examine the quality of VGI for an educational planning task in Islamabad, Pakistan, and show that while the data may be suitable for route finding tasks, they are insufficient for educational planning alone.

scholarly journals Quality Verification of Volunteered Geographic Information Using OSM Notes Data in a Global Context

2020 ◽  
Vol 9 (6) ◽  
pp. 372
Author(s):  
Toshikazu Seto ◽  
Hiroshi Kanasugi ◽  
Yuichiro Nishimura
Keyword(s):  
Quality Management ◽  
Geographical Distribution ◽  
Regional Differences ◽  
User Interaction ◽  
Volunteered Geographic Information ◽  
Geographic Information ◽  
Positional Accuracy ◽  
New Approach ◽  
Global Context

Although the data obtained from volunteered geographic information (VGI) are inherently different from public surveys, the quantity of the data are vast and the quality of the data are often poor. To improve the quality of VGI data, the positional accuracy and diversity and interaction of the number of users involved in the regional generation of the data are important. This research proposes a new approach for the accumulation of OpenStreetMap (OSM) data by using OSM Notes and attempts to analyze the geographical distribution and the characteristics of the contents of the contributions, quantitatively and qualitatively. Subsequently, the results demonstrated regional differences in OSM Notes, but it provided users with an understanding of the new features of quality management in OSM, even in regions where OSM activities are not necessarily active. In addition, it was also possible to discover new factors such as the time transition required for the correction and contribution of anonymous users. These results are expected to serve as a tool for users to communicate with each other to resolve data bugs that exist in OSM and provide future researchers with examples of user interaction in global OSM activities.

Assessing The Quality of Water Depth Derived From Volunteered Geographic Information (VGI) For Flood Monitoring. A Case Study of Hurricane Harvey In Harris County, Texas

2021 ◽  
Author(s):  
Abdullatif Alyaqout ◽  
T. Edwin Chow ◽  
Alexander Savelyev
Keyword(s):  
Water Depth ◽  
Temporal Distribution ◽  
Volunteered Geographic Information ◽  
Temporal Variations ◽  
Geographic Information ◽  
Text Messages ◽  
Quality Of Water ◽  
Significant Difference ◽  
Flood Monitoring

Abstract The primary objectives of this study are to 1) assess the quality of each volunteered geographic information (VGI) data modality (text, pictures, and videos), and 2) evaluate the quality of multiple VGI data sources, especially the multimedia that include pictures and videos, against synthesized water depth (WD) derived from remote sensing (RS) and authoritative data (e.g. stream gauges and depth grids). The availability of VGI, such as social media and crowdsourced data, empowered the researchers to monitor and model floods in near-real-time by integrating multi-sourced data available. Nevertheless, the quality of VGI sources and its reliability for flood monitoring (e.g. WD) is not well understood and validated by empirical data. Moreover, existing literature focuses mostly on text messages but not the multimedia nature of VGI. Therefore, this study measures the differences in synthesized WD from VGI modalities in terms of (1) spatial and (2) temporal variations, (3) against WD derived from RS, and (4) against authoritative data including (a) stream gauges and (b) depth grids. The results of the study show that there are significant differences in terms of spatial and temporal distribution of VGI modalities. Regarding VGI and RS comparison, the results show that there is a significant difference in WD between VGI and RS. In terms of VGI and authoritative data comparison, the analysis revealed that there is no significant difference in WD between VGI and stream gauges, while there is a significant difference between the depth grids and VGI.

An Assessment of Several Taxonomies of Volunteered Geographic Information

2013 ◽  
pp. 1794-1808
Author(s):  
Antony K Cooper ◽  
Serena Coetzee ◽  
Derrick G Kourie
Keyword(s):  
Spatial Data ◽  
Formal Concept Analysis ◽  
Geographic Information ◽  
Geographical Information ◽  
User Generated Content ◽  
Formal Concept ◽  
Data Bases ◽  
Data Infrastructures ◽  
Spatial Data Infrastructures ◽  
Official Data

User-Generated Content (UGC) in general, and Volunteered Geographical Information (VGI) in particular, are becoming more important as sources for official data bases, such as those used in national Spatial Data Infrastructures (SDIs). Discovering and assessing VGI as suitable geospatial resources for one’s purposes is hence becoming more important, but can be difficult. One way of assessing VGI resources is by classifying them into different types of resources, i.e. a taxonomy of resources. The question is whether such taxonomies can accurately identify suitable VGI resources. We assess five taxonomies both subjectively and using formal concept analysis to determine their discrimination adequacy, that is, how well the taxonomies discriminate between repositories containing UGC in general, or VGI in particular.

scholarly journals The Spatial-Comprehensiveness (S-COM) Index: Identifying Optimal Spatial Extents in Volunteered Geographic Information Point Datasets

2020 ◽  
Vol 9 (9) ◽  
pp. 497
Author(s):  
Haydn Lawrence ◽  
Colin Robertson ◽  
Rob Feick ◽  
Trisalyn Nelson
Keyword(s):  
Social Media ◽  
Data Quality ◽  
Spatial Scales ◽  
Volunteered Geographic Information ◽  
Geographic Information ◽  
Quality Metric ◽  
Fine Grained ◽  
Multi Scale ◽  
Feasible Study

Social media and other forms of volunteered geographic information (VGI) are used frequently as a source of fine-grained big data for research. While employing geographically referenced social media data for a wide array of purposes has become commonplace, the relevant scales over which these data apply to is typically unknown. For researchers to use VGI appropriately (e.g., aggregated to areal units (e.g., neighbourhoods) to elicit key trend or demographic information), general methods for assessing the quality are required, particularly, the explicit linkage of data quality and relevant spatial scales, as there are no accepted standards or sampling controls. We present a data quality metric, the Spatial-comprehensiveness Index (S-COM), which can delineate feasible study areas or spatial extents based on the quality of uneven and dynamic geographically referenced VGI. This scale-sensitive approach to analyzing VGI is demonstrated over different grains with data from two citizen science initiatives. The S-COM index can be used both to assess feasible study extents based on coverage, user-heterogeneity, and density and to find feasible sub-study areas from a larger, indefinite area. The results identified sub-study areas of VGI for focused analysis, allowing for a larger adoption of a similar methodology in multi-scale analyses of VGI.

scholarly journals Smartphone-assisted spatial data collection improves geographic information quality: pilot study using a birth records dataset

2016 ◽  
Vol 11 (3) ◽  
Author(s):  
Xiaohui Xu ◽  
Hui Hu ◽  
Sandie Ha ◽  
Daikwon Han
Keyword(s):  
Pilot Study ◽  
Data Collection ◽  
Spatial Data ◽  
Information Quality ◽  
Reference Method ◽  
Application Programming Interface ◽  
Geographic Information ◽  
Aerial Image ◽  
Positional Accuracy ◽  
Birth Records

It is well known that the conventional, automated geocoding method based on self-reported residential addresses has many issues. We developed a smartphone-assisted aerial image-based method, which uses the Google Maps application programming interface as a spatial data collection tool during the birth registration process. In this pilot study, we have tested whether the smartphone-assisted method provides more accurate geographic information than the automated geocoding method in the scenario when both methods can get the address geocodes. We randomly selected 100 well-geocoded addresses among women who gave birth in Alachua county, Florida in 2012. We compared geocodes generated from three geocoding methods: i) the smartphone-assisted aerial image-based method; ii) the conventional, automated geocoding method; and iii) the global positioning system (GPS). We used the GPS data as the reference method. The automated geocoding method yielded positional errors larger than 100 m among 29.3% of addresses, while all addresses geocoded by the smartphoneassisted method had errors less than 100 m. The positional errors of the automated geocoding method were greater for apartment/condominiums compared with other dwellings and also for rural addresses compared with urban ones. We conclude that the smartphone-assisted method is a promising method for perspective spatial data collection by improving positional accuracy.

scholarly journals The GeoWeb and everyday life: An analysis of spatial tactics and volunteered geographic information

First Monday ◽  
2014 ◽  
Author(s):  
Jessa Lingel ◽  
Bradley Wade Bishop
Keyword(s):  
Everyday Life ◽  
Spatial Data ◽  
Information Science ◽  
Volunteered Geographic Information ◽  
Political Efficacy ◽  
Geographic Information ◽  
Future Research ◽  
The Political ◽  
Geospatial Technologies ◽  
Opening Up

In this paper, we discuss GeoWeb technologies, specifically those created via volunteered geographic information (VGI) as a means of analyzing the political contours of mapmaking. Our paper is structured around two case studies of VGI projects that allow for consideration for the political efficacy (and potential drawbacks) of these geospatial technologies. We use de Certeau’s constructs of strategies and tactics as a conceptual framing, which allows for a political reading of geographic data couched in the context of everyday life, as well as opening up inquiry into the politics of making, accessing and interpreting spatial data. We conclude by suggesting provocations for future research on the GeoWeb and VGI at the intersection of geography and information science.

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