Overview 

This International Standard establishes the principles for describing the quality of geographic data. It:

• defines components for describing data quality;
• specifies components and content structure of a register for data quality measures;
• describes general procedures for evaluating the quality of geographic data;
• establishes principles for reporting data quality.

This International Standard also defines a set of data quality measures for use in evaluating and reporting data quality. It is applicable to data producers providing quality information to describe and assess how well a dataset conforms to its product specification and to data users attempting to determine whether or not specific geographic data is of sufficient quality for their particular application. This International Standard does not attempt to define minimum acceptable levels of quality for geographic data.

Core Concepts

Geographic data is increasingly being shared, interchanged and used for purposes other than their producers’ intended ones. Information about the quality of available geographic data is vital to the process of selecting a dataset in that the value of data is directly related to its quality. A user of geographic data may have multiple datasets from which to choose. Therefore, it is necessary to compare the quality of the datasets to determine which best fulfils the requirements of the user.

The purpose of describing the quality of geographic data is to facilitate the comparison and selection of the dataset best suited to application needs or  requirements. Complete descriptions of the quality of a dataset will encourage the sharing, interchange and use of appropriate datasets. Information on the quality of geographic data allows a data producer to evaluate how well a dataset meets the criteria set forth in its product specification and assists data users in evaluating a product’s ability to satisfy the requirements for their particular application. For the purpose of this evaluation, clearly defined procedures are used in a consistent manner.

To facilitate comparisons, it is essential that the results of the quality reports are expressed in a comparable way and that there is a common understanding of the data quality measures that have been used. These data quality measures provide descriptors of the quality of geographic data through comparison with the universe of discourse. The use of incompatible measures makes data quality comparisons impossible to perform. This International Standard standardises the components and structures of data quality measures and defines commonly used data quality measures.

This International Standard recognizes that a data producer and a data user may view data quality from different perspectives. Conformance quality levels may be set using the data producer’s product specification or a data user’s data quality requirements. If the data user requires more data quality information than that provided by the data producer, the data user may follow the data producer’s data quality evaluation process flow to get the additional information. In this case the data user requirements are treated as a product specification for the purpose of using the data producer process flow.

The objective of this International Standard is to provide principles for describing the quality for geographic data and concepts for handling quality information for geographic data, and a consistent and standard manner to determine and report a dataset’s quality information. It aims also to provide guidelines for evaluation procedures of quantitative quality information for geographic data.

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