Information Technology Reference
In-Depth Information
vergence of previously unrelated and deeply contrasting traditions. “A
confluence of fundamental quantities always is intriguing” (Berger 2000,
661) and may yield insights not obtainable from either discourse in isola-
tion. The intention, both in the direct treatment of information theory
and for the analogies with concepts from linguistics, remains an enhanced
understanding of the condition within which human choice operates,
rather than implementing deterministic computations, beyond reveal-
ing the basis for Boolean operations. The emphasis on human choice is
consistent with this topic's treatment of semantics, but contrasts with
the dominant deterministic approach to the use of information theory in
retrieval.
Messages for Selection and Message
In information theory, the message and messages for selection are fun-
damental and interrelated components of a coherent and comprehen-
sive model of communication; communication is understood primarily
as the transmission of signals across telecommunication channels. In the
model of communication developed for information theory, an informa-
tion source chooses from messages for selection and then combines them
into a message. In its technical and deliberately intratheoretic sense, infor-
mation is a measure of freedom of choice in selecting messages from the
source. Measures of information can be derived directly from the mes-
sage if the stability of the statistical characteristics of messages is present
or assumed across the samples analyzed. The message is then passed to
a transmitter, which operates on the message to produce a signal for
transmission before sending it across a communication channel; noise in
the communication channel is assumed. The communication channel is
linked to a receiver, which operates on the signal to transform it into a
message that can be passed to the destination. The information source,
transmitter, receiver, and destination can be a combination of human and
technology. For instance, the information source could be a printer that
selects messages from a type font, or a person who composes a telegram
and implicitly chooses from the lexicon of the language, in accord with
the combinative constraints of syntactically acceptable telegraphic mes-
sages. For a telegraphic message, the transmitter would be a combination
