ribe data source material and method.
- Positional accuracy: it is the accuracy of the coordinates, and it also can be expressed as the absolute accuracy and relative accuracy. The accuracy of the position of features whether in two or three dimensions: vertical and horizontal position precision.
- Attribute accuracy: This is the level of adherence to logical rules of data structure, attribution and relationships. Also reflects the estimates of the truth. Explain and describe boundary and characteristics of woodland soil or polygon is extremely difficult and subjective.
- Logical consistency: the fidelity of relationships encoded in the data structure
- Completeness: This is the presence and absence of objects in a dataset at a particular point in time. To assess how many objects are expected to be found in the database but missing and an assessment of the surplus data should not be included (such as buildings now demolished). In other words, how is data set to fully cover the object of the real world.
- Semantic accuracy: Emphasized the importance of the internal connection of data elements quality, i.e., described in addition to the error of uncertainty
- Usage, purpose, and constraints: It is a purpose statement to help potential users in determining data.
- Temporal quality: It is the accuracy of temporal attributes for reaction in the real world changes and update speed in relationship database.
- Thematic accuracy: This is a quantitative attribute about right opposite the attribute to the corresponding physical distribution.
Hence, in some of these elements mentioned before are used to analyze the quality of the OSM map.
The Volunteered Geographic Information and OpenStreetMap
GoodChild (2007) for the first time put forward the volunteered Geographic Information (VGI) concept. At present about VGI have not form a unified definition. GoodChild (2007) believed VGI must set the following three elements: web 2.0, the collective wisdom (Smith, 1994) the new geography (Tunner, 2006), and it reflects the new acquisition and application of geographic information for the Internet age. Li and Qian (2010) from the perspective of broad sense and narrow sense to explained VGI, they considered narrow VGI is composed of a non-expert users using the 3s technology spontaneously create geographic information; Generalized VGI is with narrow VGI related concepts, patterns, methods and techniques. Wikipedia in the definition of VGI is refers to the user through the way of online collaboration, handheld GPS terminals, open access to ordinary high resolution remote sensing images, and personal space cognitive reference, on the basis of the geographical knowledge creating, editing, management and maintenance of geographic information. This paper argues that VGI refers to ordinary users via Internet spontaneously complete with spatial information data collection, processing, management and maintenance.
VGI is widespread impact of emerging geographical information industry. In early 2012, the famous American social media positioning service provider Foursquare and the world's leading mobile phone and PC maker Apple announced that using Google Maps, turned to the broad prospects for development and OpenStreetMap data free VGI website, visible VGI has geographic information data of the traditional industry has a strong impact.
VGI information mainly comes from the user's voluntary contribution, its core idea is GoodChild (2007a, 2007b), "everyone is sensor", that is, everyone can complete the geog
