66 3. The Code Model Decoded
From an information theoretic perspective, the semantic intentions of the woman are irrelevant.
The transmitter and receiver are only concerned with how the constructed message may be related to the set of possible primary messages in this case the set of
characters composing the English alphabet and the signal alphabet in this case the set dots and dashes defined by Morse Code.
For readers not directly concerned with the information theoretic perspective on communication, this distinction between message and signal may seem superfluous—a
“quibble over semantics.” Indeed, most linguists have handled it so, as the code model quotations presented in section
2.4 illustrate. This practice has reflected a grave
misunderstanding, for as will be seen, it is a very significant distinction. Indeed, this misunderstanding andor disregard for this distinction has been one of the major factors
contributing to the integration of the conduit metaphor with Shannon’s information theory.
3.2.3.1.3. Transmitter and receiver
Shannon specifies that, in addition to having a well established definition of acceptable messages, “The system must be designed to operate for each possible
selection, not just the one which will actually be chosen since this is unknown at the time of design”
Shannon 1948 :379,
1949 :3. This may apply to previously undefined strings
of characters or to already defined strings of characters. If a single message or fixed arrangements of characters were to be accepted as possible messages, then the signal
need not correspond to the respective characters in those messages, but only to the respective fixed arrangements as wholes. Weaver addresses such a situation in discussing
the fact that information does not concern semantics:
The concept of information applies not to the individual messages as the concept of meaning would, but rather to the situation as a whole, the unit information indicating that in
this situation one has an amount of freedom of choice, in selecting a message, which it is convenient to regard as a standard or unit amount.
The two messages between which one must choose, in such a selection, can be anything one likes. One might be the text of the King James Version of the Bible, and the other might
be “Yes.” The transmitter might code these two messages so that “zero” is the signal for the first, and “one” the signal for the second; or so that a closed circuit current flowing is the
signal for the first, and an open circuit no current flowing the signal for the second. Thus the two positions, closed and open, of a simple relay, might correspond to the two messages.
Weaver 1949b :100
Obviously, Shannon’s theory requires that the transmitter and receiver both be capable of handling the message. In describing the components in the communication
process, Shannon termed it so:
A transmitter which operates on the message in some way to produce a signal suitable for transmission over the channel. …
The receiver ordinarily performs the inverse operation of that done by the transmitter, reconstructing the message from the signal.
Shannon 1948 :381,
1949 :6
3. The Code Model Decoded 67
