Geography Reference
In-Depth Information
Data Quality
This part deals with the quality of spatial data as a variable used to visualize
uncertainty in spatial data. Therefore, in the beginning of this chapter, we must
define notions and mutual relationships that are used in the text and thus illustrate
problematic and ambiguous view of data and information with geographic or spatial
aspects. The definition of the notion spatial data itself is difficult, and there are often
problems with terminology and correct understanding of the meaning of this
expression. In practice, there is not only this notion, but a whole spectrum of
notions bearing similar and often confused meaning.
To determine and define the quality of spatial data, the actual meaning of the
word
quality
must be understood. Moreover, the notion quality must be used with
great discretion, because the notions uncertainty and quality of spatial data are not
synonyms, although, in many cases, they are very close to each other. They have
similar categories, deal with similar domains and in many cases, quality is confused
with uncertainty and vice versa (Brus et al.
2013
). Uncertainty in this meaning is
considered a property allowing to evaluate how good (of what quality) are the
available data, and uncertainty distinctively influences the quality of spatial data.
Basic and distinctive difference is the fact that uncertainty can be introduced in any
phase of the production of mapping data and GIS analyses (monitoring, conceptual
modelling, measuring, analysis, visualization etc.) including perception by the end
users, and as such, it concerns not only the quality of the spatial data, but the whole
process of transferring geographic information.
The notion of quality and its contents has been undergoing historical develop-
ment and transformation. From this point of view, it must be deciphered not only as
part of the given context and discourse of the scientific field, but also with regard to
its genetic and semantic interpretation. Thus, quality in the meaning of this paper
can be most conveniently defined as each property or quality that belongs to
something, or is connected to something, as the thing that modifies the thing to
fulfil its purpose for which it was created or founded (Brugger
1994
), and quality
means the quality of the acquired information. From this point of view, a high-
quality piece of information can be considered such piece of information that is
useful and helpful for its “consumer”, which, in connection with traditional defini-
tion of information means that the information quality is very dependant not only on
basic data, but on the users themselves. High-quality information can then be
defined as “accurate, trustworthy and sufficient for the decision-making of the
user”. In connection with the possibility to interpret data and information in many
ways, also above-mentioned knowledge (tacit, explicit) and experience of the
originator and recipient of the information enter the process. Therefore, it is very
interesting to consider also the efficient quality of information—actual usefulness
where an important factor is the skills of the information user. For users without
sufficient skills, information is not of high-quality (useful), but, quite to the
contrary, the quality of the presented information can even decrease. This fact is
also reflected by the used definition of quality “convenience of use” (Beard
