Presuppositions in Spoken Discourse

Chapter 5
5.4 IS THERE A PREFERENCE FOR HIGHER LEVELS OF ACCOMMODATION?
Both Heim and van der Sandt have suggested that higher levels of accommodation
will be preferred over lower levels and evaluating the likelihood of this proposed
preference in relation to the corpus results is the third main question for this
chapter. These preferences should have resulted in GLOBAL being more frequent
than LOCAL or INTERMEDIATE, and INTERMEDIATE more frequent than LOCAL.
First I will present several explanations given in the literature for why there
should be a preference for higher levels of accommodation over lower. Then I’ll
discuss these in relation to the corpus data. Factive presuppositions were locally
accommodated as often as globally, so the data does not show a tendency for
higher levels of accommodation over lower levels for all trigger types. I’ll present
an alternative proposal, that there is no general preference for higher levels of
accommodation, and that triggers differ in the likelihood with which they will be
used under embedding, and the behavior of the induced presupposition will also
differ depending on the type of embedding.
There are two well discussed accounts for the proposed preference,
contrasted at length in Geurts (2001). The first proposal is that backgrounded
information tends to float up to the main context. Because presuppositions are
arguably a kind of backgrounded information they also tend to float up. This
proposal was made by Geurts (1999, 2001), and he terms it the Bouyancy Principle,
or BP. Geurts comments that it still remains to be explained why background
information should float up, so the BP isn’t really an explanation. The second
proposal argues that the proposed preference is related to the desire of speakers to
make the strongest reading possible. Presupposed information projected to the
main context is argued to result in a stronger reading than non-globally
accommodated versions, so hearers will tend to globally accommodate. This
account is advocated by those working on Optimality Theory treatments of
presupposition (e.g. Blutner 2000, Zeevat to appear) and is captured by the
workings of Blutner’s (2000) proposed constraint BESTRONG. Semantic strength is
usually defined in the following way: consider two possible readings for an
utterance, reading A and reading B. If reading A entails reading B but reading B
does not entail reading A, then reading A is stronger because it would add more
information to the context than reading B, hence Geurts (2001) terms this the
Informativeness Principle, or IP.
A simple example of how the IP works is given below. The interpretation of
the DRS when the presupposition triggered is globally accommodated, (43)b,
entails the interpretation of the DRS when the same presupposition is locally
accommodated, (43)c, but not vice-versa.
(43) a. If the King of France is bald, then he lives in exile.
b. [ x : KofF(x) [ bald(x) ] → [ lives_in_exile(x) ] ]
c. [ [x : KofF(x), bald(x) ] → [ lives_in_exile(x) ] ]
138