THE ROLE OF QUALITY IN SPATIAL DATA INFRASTRUCTURES
A.J. Jakobsson1, L. Tsoulos2
1 - National Land Survey of Finland
2 - National Technical University of Athens
Already in the 1980’s, data quality was recognized as an important issue in cartography (e.g. Chrisman, 1982). Goodchild and Gopal edited a book on the accuracy of spatial databases in 1989. At the beginning of 1990, the development of GIS created a need to define data quality in geographic information (e.g. Buttenfield, 1993). In the Spatial Data Transfer Standard (SDTS), five quality elements were described (FGDC, 1991): lineage, positional accuracy, attribute accuracy, completeness, and logical consistency. This was followed by the ICA book on spatial data quality (Guptill & Morrison, 1995) introducing two more elements: Semantic Accuracy and Temporal Accuracy. Goodchild and Jeansoulin edited a book entitled “Data Quality in Geographic Information, From Error to Uncertainty” in 1998, which reflected widening of the concept of data quality. The description of a European quality standard started at the beginning of the 1990’s and resulted in a pre-standard in 1998. When international standardisation begun in 1996, it was decided to build the ISO 19113 on the existing CEN standard. We can name these efforts as ‘truth-in-labelling’ and regard them also as based on the production-centred view of quality.
The term Spatial Data Infrastructure is described in the SDI cookbook (Nebert, 2004) as “the relevant base collection of technologies, policies and institutional arrangements that facilitate the availability of and access to spatial data.” European Parliament, Council and Commission have agreed on the content of the directive for European Spatial Infrastructure (INSPIRE) and European countries have to implement legislation by 2009. This paper will discuss how quality should be taken into account in the development of national SDIs.
First different quality concepts are described using four quality management viewpoints: production centred, planning centred, customer centred and system centred. System centred view is argued to be the most important from the SDIs point-of –view.
Harmonization is one of the major challenges in the implementation of SDI and a special challenge for the ESDI. Normally the harmonization process includes describing a common schema with quality requirements. Quality requirements are not commonly described at the moment, while ISO 19113 and ISO 19114 standards can be utilized for the description of the requirements. Most of the efforts in SDI development have been concentrating on solving the interoperability issues at data or system level. Organizational issues have nearly been ignored. Quality is often regarded as one of the metadata labels, which can be solved by reporting it to the users.
The paper will introduce and discuss some new ideas on how quality should be managed in national SDI programmes. These include quality models for data production, quality accreditation, certification and auditing.
Finally we discuss the benefits of introducing the quality to SDI programmes.