LIS 677 - Definitions

Section A

Assigned or assignment or controlled indexing
Indexing with terms from a controlled list.
Extraction indexing
Indexing with terms from the text, abstract, or title of the item indexed.
Free-text searching
Searching using uncontrolled vocabulary, such as that found in titles, abstracts, or full text.
Full-text database
A database that contains the full text of documents, rather than just citations, abstracts, or other surrogates.
Precision ratio
The ratio of the number of relevant items retrieved to the total number of items retrieved.
Recall ratio
The ratio of the number of relevant items retrieved to the total number of relevant items indexed.
Stoplist
A list of words or other character strings that are not to be used as initial terms in index entries.
BT
A symbol used in thesauri to identify the following term(s) as (a) broader term(s) to the heading term.
NT
A symbol used in thesauri to identify the following term(s) as (a) narrower term(s) to the heading term.
The most usual broader/narrower term relationship is one of genus/species: the narrower term refers to a subclass of the class of things referred to by the broader term.
RT
A symbol used in thesauri to identify the following term(s) as (a) related term(s) to the heading term.
Two terms are related terms to one another if they are both allowed in indexing and have a close paradigmatic relationship but neither is a narrower or broader term to the other.
SN
A symbol used in thesauri to indicate that what follows is a scope note to the heading term.
A scope note gives some indication of how the heading term is or is not to be used; it often refers to a related or overlapping term.
UF
A symbol used in thesauri to indicate that the following term is not used in indexing and that the heading term is used instead.
USE
A symbol used in thesauri to indicate that the heading term is not used in indexing and that the following term(s) is/are used instead.
Letter-by-letter filing or arrangement or alphabetizing
An alphabetical arrangement in which the entries are filed according to the letters in them, ignoring spaces and punctuation.
Word-by-word filing or arrangement or alphabetizing
An alphabetical arrangement in which spaces between words are significant.
Homograph
A word or phrase with the same spelling as, but a different meaning from, another word or phrase.

Section B

Citation indexing
Indexing in which each term uniquely identifies a document cited by the item indexed.
Exhaustivity of indexing
The degree to which an item is indexed by all applicable terms.
Specificity of indexing
The degree to which a concept is specified in detail in indexing.
Relevance
The characteristic of being appropriately retrieved in response to a given query.
Pertinence
The characteristic of being both relevant and useful to the needs of a particular enquirer at a particular time.
Precoordination
The combination of terms or other components to form compound terms at or before the time of indexing.
Postcoordination
The combination of terms at the time of retrieval to form a compound search specification that corresponds to no single index term used in indexing.
Enumerative
Of an indexing or classification scheme, listing or enumerating terms explicitly, rather than making provision for synthesizing them.
Synthetic
Of an indexing or classification scheme, making provision for the synthesis of terms out of components, rather than listing or enumerating them explicitly.
Paradigmatic or semantic relation
A relation between terms that is true as a matter of general knowledge, rather than depending on what the terms refer to in some particular document.
Syntagmatic or syntactic relation
A relation between terms that depends on what the terms refer to in some particular document, rather than being true as a matter of general knowledge.
Role indicator
A character, mark, or short abbreviation which can be applied to a term so that the function ascribed to it in a given context (e.g., raw material, process, product) may be identified.
Weighting
The assignment of differential values, or weights, to terms either in a query or as assigned to a document.
Citation or combination order
The order in which the terms or other components are combined or cited in precoordination.
Quasi-synonym
A term which is treated as equivalent to another term for purposes of indexing even though the two terms are not synonymous.
Chain
A sequence of terms in which the class represented by each term includes all the classes represented by the terms that follow that term.

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Last updated September 8, 2004.
This page maintained by Prof. Tim Craven
E-mail (text/plain only): craven@uwo.ca
Faculty of Information and Media Studies
University of Western Ontario,
London, Ontario
Canada, N6A 5B7