1. A method of generating information from a plurality of data items, the method comprising the steps of: (a) populating an aggregate data item with at least one of the plurality of data items; wherein each individual data item comprises original information including an attribute and a value, wherein the attribute of the individual data item is an identifier for the individual data item, wherein the aggregate data item is a form of derived attribute, wherein the derived attribute represents a transformation of a collection of individual data items into a single data item with a value, wherein said value of the derived attribute is an aggregate value comprising a map of attribute to value for each said individual data item within said collection of individual data items such that a derived attribute forms a single data item suitable for inferencing by a knowledge base, said single data item retaining the original information relating to each of the plurality of individual data items yet queried by the knowledge base as a whole to extract information regarding said individual data items; and (b) generating the information using the aggregate data item, wherein the method of generating information is performed by a decision support system, and wherein the information so generated falls into one or more of the following groups: i. textual information; ii. a machine instruction.
37. A method defined by claim 1 further comprising: applying a rule to said aggregate data item, wherein said rule is applied by a rules-based knowledge base, wherein said rule includes a set operation that includes at least one of the following operations performed on said collection of individual data items: querying; iterate over; identifying subsets; identifying a specific individual data item; sorting; and comparing the collection of individual data items with other collections of individual data items; wherein said rule is able to query said plurality of individual data items as a single data item rather than relying on a plurality of rules for each individual data item or a combination thereof.