On the Optimality of Vagueness:
“Around”,“Between” and the Gricean Maxims∗
Paul Egré, Benjamin Spector, Adèle
Mortier, Steven Verheyen
[Link to R scripts which implement models discussed in the paper]
Why
is our language vague? We argue that in contexts in which a cooperative speaker
is not perfectly informed about the world, the use of vague expressions can
offer an optimal tradeoff between truthfulness (Gricean Quality) and
informativeness (Gricean Quantity). Focusing on expressions of approximation such
as “around”, which are semantically vague, we show that they allow the speaker
to convey indirect probabilistic information, in a way that gives the listener
a more accurate representation of the information available to the speaker than
any more precise expression would (intervals of the form “between”). We give a
probabilistic treatment of the interpretation of “around”, and offer a model
for the interpretation and use of “around”- statements within the Rational
Speech Act (RSA) framework. Our model differs in substantive ways from the
Lexical Uncertainty model standardly used within the RSA framework for vague
predicates.
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