Top Term (TT)

Use the top term operator (TT) to replace a term in a query with the top term that has been defined for the term in the standard hierarchy (Broader Term [BT], Narrower Term [NT]) in a thesaurus. A top term is the broadest conceptual term related to a given query term. For example, a thesaurus might define the following hierarchy:

DOG
   BT1 CANINE
     BT2 MAMMAL
       BT3 VERTEBRATE
         BT4 ANIMAL

The top term for dog in this thesaurus is animal.

Top terms in the generic (BTG, NTG), partitive (BTP, NTP), and instance (BTI, NTI) hierarchies are not returned.

Syntax

Syntax Description
TT(term[,thes]) Replaces the specified word in a query with the top term in the standard hierarchy (BT, NT) for term.

term

Specify the operand for the top term operator. term is replaced by the top term defined for the term in the specified thesaurus. However, if no TT entries are defined for term, term is not replaced in the query expression and term is the result of the expansion.

You cannot specify expansion operators in the term argument.

thes

Specify the name of the thesaurus used to return the expansions for the specified term. The thes argument is optional and has a default value of DEFAULT. A thesaurus named DEFAULT must exist in the thesaurus tables if you use this default value.

Example for TT Operator

The term dog has a top term of animal in the standard hierarchy of a thesaurus. A TT query for dog returns all documents that contain the phraseanimal. Documents that contain the worddog are not returned.

CTX_THES.TT for more information on browsing the top terms in your thesaurus