Presuppositions in Spoken Discourse

Chapter 5
examine what the information was to the speaker and what purpose or role it
served in the discourse. 4
Presupposed information that the hearer has to accommodate could be
shared knowledge, or hearer-old, or it could be hearer-new. If it is shared knowledge it is part
of the common ground between the participants, but has not yet been expressed or
made salient in the current discourse. Then it seems to perform a reminding
function, making known information that is needed in order to provide
background for non-presupposed information, perhaps making the message more
coherent. This potential function of presupposition is discussed in Delin (1995) and
is often an implicit assumption in much discussion of presupposition.
Another reason why shared information must perhaps be activated in a
discourse may have to do with reasoning. Walker (1996) has suggested that logical
conclusions cannot be made unless all premises are activated and available. If the
discourse participants share an important element of background information
which is needed as a premiss to support a conclusion, this information may need to
be introduced into the discourse first before the conclusion could be made. This
could possibly be a role played by shared presuppositions in discourse, given that
presuppositions are generally treated as background knowledge, i.e. information
that is taken for granted, this seems to be an appropriate form by which to
introduce such information.
Information that is hearer-known but discourse-new has a different status
than information already given. The former is not activated at the time when it is
used, whereas the latter might be. Most theories of discourse make a distinction
between information that is activated or salient and information that is perhaps
being retrieved from e.g. main memory.
Presupposed information that must be accommodated could also be
information assumed by the speaker to be hearer-new. The claim that some trigger
types are clearly being used to intentionally introduce hearer-new discourse
information as a major usage is still somewhat controversial, despite the earlier
corpus work that has shown that it is a common use for the presuppositions
associated with some triggers, e.g. see Prince’s (1978) work on information bearing
it-clefts, and Delin’s (1995) work on it-clefts, as well as the many studies of definite
NPs, in particular Fraurud (1990) and Poesio & Vieira (1998). This earlier work for
the most part comes from written corpora. We know very little however about how
frequent this type of usage is for spoken discourse, or for factives.
Another generally agreed upon feature of presupposition is that, whether
discourse-given, hearer-old or hearer-new, the presupposed information generally
4 Conclusions we can make from the figures for accommodation are therefore very different
from those we can make from the examples of binding, where we can assume that the annotator
and the discourse participants were both aware of the information because it was discourse-given,
and something can easily be said about the function of bound presuppositions based on the
transcript alone. The speaker’s message is not intended for the annotator and the hearer’s
interpretation can differ from the annotator, so we need to try to determine what the participants
meant and understood by looking at other utterances.
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