Presuppositions in Spoken Discourse

Chapter 1
work about presupposition, which has focused on the similarities between triggered
presuppositions rather than their potential differences.
I will argue that the corpus data shows that abstract presuppositions seem to
be used and perceived by discourse participants in a manner similar to discourse
anaphora. I will present cases where the use of presupposed information shares
many of the characteristics identified as typical of discourse anaphora. Even in
cases where a resolution by binding or a resolution by accommodation would not
make a perceivable truth-conditional difference, discourse participants do seem to
perceive bound presuppositions similarly to anaphoric expressions.
Additionally, bound abstract presuppositions have a discourse function in
addition to their semantic function when they occur naturally produced in context.
In cases where the presuppositional expression could have been replaced with a
pronominal anaphor, and where the semantic contribution would have been the
same, I maintain that an abstract presuppositional expression can have additional
communicative utility, either by more precisely referring to an abstract idea present
in the earlier context, or by contributing rhetorical effect by emphasizing a feeling
of parallelism or contrast. Presuppositional expressions can also help to summarize
more precisely information referred to in the discourse and help make implicit
conclusions explicit. These are all functions that pronominal anaphor cannot serve
or do not serve as well.
The corpus results do not yield evidence that a hierarchical discourse
structure constrains the search for antecedents for presupposed information as has
been suggested for anaphoric expressions. Presupposed information seems to be
able to be used in a freer manner, perhaps because of its greater descriptive
content.
The binding theory considers presupposed information to differ from empty
anaphoric information such as pronominal anaphors in one important respect: a
presuppositional expression can create its own antecedent if the discourse does not
provide one via the process of accommodation. The status of accommodated
information, when it is used, why it is used, what licenses it, and preferences for its
interpretation, is not clear. Most work on accommodation is highly theoretical. Our
understanding of accommodation therefore would benefit from looking at naturally
produced examples and here I hope to make a contribution.
There is a general misconception that presupposed information will be
shared information. However, in the corpus, the majority of the presuppositions
triggered by factive verbs that needed to be accommodated were believed by the
speaker to be new to the hearer. Often the point of the utterance was the
presupposed information. This confirms earlier empirical observations that other
presupposition triggers, in particular it-clefts (Prince 1978, Delin 1995) and definite
descriptions (Fraurud 1990, Poesio & Vieira 1998) can intentionally contribute
hearer-new information.
We still know little about what factors make it possible to understand
accommodated information, and what affects the speaker’s choice of an expression
that must be accommodated. I will argue that neither of the two explanations for
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