1. A graphical user interface residing in memory, comprising: a) a query specification display area for specifying result fields and operators to define an abstract query, each result field corresponding to a logical field specification of a data abstraction model describing data in a database, wherein the data abstraction model comprises metadata for mapping the result fields to the data in the database and wherein the logical field is associated with a specific set of data in the database and is used to describe the specific set of data; b) a classification field specification display area for specifying classification fields for the abstract query, each classification field being configured to determine classified information related to the specific set of data associated with one of the logical fields, the classification field specification display area comprising: a result field window displaying a plurality of available result fields; and a plurality of graphical elements configured to allow specification of classification definitions for one or more selected result fields from the plurality of available result fields, each classification definition specifying how to divide data to be returned for a corresponding selected result field into a plurality of categories; c) a first selection element for specifying whether the specified classification fields will be included with the abstract query for execution; and d) a second selection element for initiating execution of the abstract query according to the selection made using the first selection element.