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with the following quality dimensions: accuracy, consistency, completeness, timeliness,
query frequency, source availability, and accepted response time. Associated
with timeliness, we also add currency and volatility.
??? Accuracy: Measures how close to the value in the real world the data under
consideration are. Another vision, from the ontological point of view, defines
inaccuracy as the probability that an information system represents an incorrect
state of the real world (Wand & Wang, 1996). The accuracy of a data
warehouse is influenced by two main factors: (a) accuracy of the data sources
and (b) the error factor that the ETL process can introduce.
??? Consistency:. We adopt the ontological point of view, which describes consistency
as the ???logical consistency??? of information. The underlying idea is
that given two instances of representation for the same data, the value of the
data must be the same. For example, if it is known that the sales of a company
exceed a certain monthly value v, we expect the database to reflect this fact.
??? Completeness:.Is the information system able to represent every significant
state of the real world. The methodology presented here emphasizes representation
instead of structure.
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