Information Technology Reference
In-Depth Information
of the Roman alphabet; the message is understood as syntactically and
orthographically acceptable written sequences from the English language
lexicon. The level of granularity at which the messages for selection are
conceived stops at the individual character, without giving direct attention
to such features as intercharacter or mosaic differentiation and redun-
dancy, although the existence and function of these features is recognized
(Cherry 1978; Warner 2003, 551). Thus, the message in information the-
ory is understood as constructed from individual messages for selection
and combined into a linear sequence or message.
Message
In information theory, the message emerges in two forms: the message
for sending, passed from the information source to the transmitter, and
the message reconstructed by the receiver from the received signal and
passed to the destination. Classically, information theory was concerned
with ensuring a close correspondence between the message sent and the
message received, accepting that a signal would be perturbed by noise in
the communication channel. The message is identical with the signal for
certain uses of writing—handwritten, typed, or printed forms used for
communication over distance—and neither transmitter nor receiver oper-
ates significantly on the message or signal. Selection errors and noise (for
instance, orthographic mistakes and printing failures) are still possible,
and some suggest that redundancy in written language was deliberately
introduced to enable reconstruction of the message intended to be sent
(Warner 2003). For other historically subsequent uses of writing, such as
telegraphy and e-mail, the transmitter and receiver operate on the mes-
sage and received signal, and technology displaces direct human labor
and intervention over time.
We are concerned here with the message, not the transformations
between message and signal. There are two methods for assimilating
this concern to the model of communication in information theory. The
full model could be retained, an identity between the message sent, and
the message received assumed, with the transmitter and decoder work-
ing without error and the signal not perturbed by noise. Alternatively,
the transmitter and decoder could be eliminated from the model and the
signal regarded as the message in transmission or as the message as sig-
