Sperber and Wilson (1995, 142) suggest that the goal of the comprehension process is
to maximize the relevance of any information being processed. … people hope that the assumption being processed is relevant (or else they would not bother to process it at all), and they try to select a context which will justify that hope: a context which will maximize relevance. In verbal comprehension in particular, it is relevance which is treated as given, and context which is treated as a variable.
This is another perspective on the process of ‘context construction’ described in Chapter 15. But context being holarchic, that process itself has a context. Relevance involves some relation to the known (or presupposed), but also some novelty; if i tell you what you already take for granted, that is not relevant. Relevance itself, then, is determined by context, i.e. by the ‘state of information’ (Peirce) in which the communication or ‘processing’ is situated – or in Peircean terms, in which the sign determines an interpretant.
Peirce in a 1906 text identified three kinds of interpretant:
In all cases, it includes feelings; for there must, at least, be a sense of comprehending the meaning of the sign. If it includes more than mere feeling, it must evoke some kind of effort. It may include something besides, which, for the present, may be vaguely called “thought.” I term these three kinds of interpretant the “emotional,” the “energetic,” and the “logical” interpretants.EP2:409
Naturally it is the ‘logical interpretant, the conveyed thought’ (EP2:410) which is most crucial for a sign involved in a process of dialog or inquiry; and ‘the essence of the logical interpretant’ (EP2:412) is the habit which is established or modified by that semiosic process. Not all signs can have a logical interpretant, and even a sign which would have one if the semiotic process were completed may not produce it in an actual semiotic process, depending on the timing:
It is not to be supposed that upon every presentation of a sign capable of producing a logical interpretant, such interpretant is actually produced. The occasion may either be too early or too late. If it is too early, the semiosis will not be carried so far, the other interpretants sufficing for the rude functions for which the sign is used. On the other hand, the occasion will come too late if the interpreter be already familiar with the logical interpretant, since then it will be recalled to his mind by a process which affords no hint of how it was originally produced. Moreover, the great majority of instances in which formations of logical interpretants do take place are very unsuitable to serve as illustrations of the process, because in them the essentials of this semiosis are buried in masses of accidental and hardly relevant semioses that are mixed with the former.EP2:414
What makes a semiosis ‘relevant’ or essential (rather than accidental) to the formation of a logical interpretant? To deal with this question, Peirce constructs a scenario of an inquiry process and conducts a thought-experiment to investigate how it works.
The best way that I have been able to hit upon for simplifying the illustrative example which is to serve as our matter upon which to experiment and observe is to suppose a man already skillful in handling a given sign (that has a logical interpretant) to begin now before our inner gaze for the first time, seriously to inquire what that interpretant is. It will be necessary to amplify this hypothesis by a specification of what his interest in the question is supposed to be.… unless our hypothesis be rendered specific as to that interest, it will be impossible to trace out its logical consequences, since the way the interpreter will conduct the inquiry will greatly depend upon the nature of his interest in it.EP2:414
The inquirer’s ‘interest’ is part of the context of the inquiry – not the ‘context which is treated as a variable’ according to Sperber and Wilson, but the situational context which determines what is essential and what is irrelevant in the text.