According to WordNet 2 the adjective "exhaustive" means
through or thoroughgoing (very thorough; exhaustively complete) "an exhaustive
study"; "made a thorough search"; "thoroughgoing research"
classification it is often demanded that classes should be collectively
exhaustive (sometimes thought of as covering the whole
universe of knowledge) and mutually exclusive, meaning that any item should have a place in
the system and that there is no overlapping between classes. This principle is
also known from probability theory:
"In probability theory, a set of events is collectively
exhaustive if at least one of the events must occur. For example,
when rolling a six-sided die, the outcomes 1, 2, 3, 4, 5, and 6
are collectively exhaustive, because they encompass the entire
range of possible outcomes.
Compare this to the concept of a set of outcomes which are
mutually exclusive, which means that at most one of the events
must occur. The set of all possible die rolls is both
collectively exhaustive and mutually exclusive." (Wikipedia,
also known in classification and indexing theory and in information retrieval.
Major and minor
descriptors are examples on how some databases applies different levels of
the two most important factors governing the effectiveness of an index language
have been thought to be the exhaustivity of indexing and the
specificity of the index language. There has been much debate about the
exact meaning of these two terms. Not wishing to enter into this controversy I
shall follow Keen and Digger in giving a working definition of each.
document, indexing exhaustivity is defined as the number of different
topics indexed, and the index language specificity is the ability of the
index language to describe topics precisely. Keen and Digger further define
indexing specificity as the level of precision with which a document is
actually indexed. It is very difficult to quantify these factors. Human
indexers are able to rank their indexing approximately in order of increasing
exhaustivity or specificity. However, the same is not easily done for
of some importance to be able to quantify the notions of indexing exhaustivity
and specificity because of the predictable effect they have on retrieval
effectiveness. It has been recognized (Lancaster) that a high level of
exhaustivity of indexing leads to high recall* and low precision*. Conversely, a
low level of exhaustivity leads to low recall and high precision. The converse
is true for levels of indexing specificity, high specificity leads to high
precision and low recall, etc. It would seem, therefore, that there is an
optimum level of indexing exhaustivity and specificity for a given user
few people (Sparck Jones[1972, 1973], Salton and Yang), have attempted to
relate these two factors to document collection statistics. For example,
exhaustivity can be assumed to be related to the number of index terms assigned
to a given document, and specificity related to the number of documents to which
a given term is assigned in a given collection" (van Rijsbergen, 1979, p. 24-25)
Keen, E. M. &
Digger, J. A. (1972). Report of an Information Science Index Languages Test.
Aberystwyth College of Librarianship, Wales.
Lancaster, F. W.
(1968). Information Retrieval Systems: Characteristics, Testing and
Evaluation. New York: Wiley.
Salton, G. &
Yang, C. S. (1973). On the specification of term values in automatic indexing.
Journal of Documentation, 29, 351-372.
Sparck Jones, K. (1972).
A statistical interpretation of term specificity and its application in
retrieval, Journal of Documentation, 28, 111-21.
Sparck Jones, K. (1973). Does Indexing Exhaustivity Matter? Journal of the
American Society for Information Science, 24(5), 313-316.
C. J. (1979). Information Retrieval. 2. ed. London: Butterworths. Online
Wellish, H. H. (1995). Indexing from A to Z.
2nd edition. New York: H. W. Wilson. (Exhaustivity pp.
The free encyclopedia. (2005). Collectively exhaustive.
Last edited: 01-08-2006