2.3.3: Data Retrieval

Data retrieval is characterized by strongly structured data.

Objects are described by tuples of attribute values, that have a well defined (and simple) type like

These types allow easy comparisons like

Tuples are selected according to these comparison operations.

ZUGANGAbb. 3: Database entries

However, to find data sets for a specific information need, it is necessary to know the semantics of the entries.

To select a "good" data set additional domain knowledge and elaborated optimization procedures are necessary.


© 1998 / HTML-Version 17. 11. 1998: R. Ferber