Presuppositions in Spoken Discourse

Anaphors and Bound Presuppositions
two linguistic expressions is very similar and the meaning of the two expressions is
also clearly the same. But we could also just simply consider this a return to an
earlier topic that the speaker wishes to pursue. The semantic similarity is strong
enough grounds to identify it as an antecedent, though there is no collaborating
evidence in the reaction of the other discourse participants which show that they
recognize that Speaker B is returning to an earlier topic, though it would seem quite
strange if they did not.
It has been argued that the only way to account for return pops is to believe
that speakers pop the focus space from the stack. This allows speakers to use
pronouns to refer to linearly distant items unambiguously, because in general longdistance
reference with pronouns like the one above should not be possible.
However, it is not entirely clear that this hierarchical structure in discourse
exists and limits the availability of antecedents, or is at all necessary to explain
anaphor resolution in cases of return pops. Walker (1996) has argued that discourse
processes that ‘operate under a limited resource constraint,’ such as ellipsis,
pronoun resolution and inferences about discourse relations, are instead affected by
the LIMITED ATTENTION CONSTRAINT. This constraint says that processing can
concentrate only on a limited number of items at a time; that is, linear recency is a
stronger factor in limiting the use of and ability to resolve these discourse processes
than hierarchical structure is, and that other information can also explain how
return pops are understood.
In order to see if hierarchical structure is really needed to account for return
pops and in order to find support for her model, Walker (1996) re-examined all the
examples in the literature. Walker points out three ways in which the antecedent of
an anaphoric pronoun for a return pop might be unambiguously signaled without
having to rely on a hierarchical structure as an explanation. 1) there may be no
other referent in the discourse with the same features, 2) the content of the first
utterance in the discourse segment that begins a return pop is sufficient to signal
what earlier context should be retrieved from main memory, 3) “the shared
knowledge of the conversants (e.g. shared knowledge of the task structure) creates
expectations…” (Walker 1996, p. 261) which allow the participants to
unambiguously predict context signaled.
In 19 out of 21 cases of return pops given in the literature, Walker found
one or more of the three clues that made the antecedent unambiguously
identifiable. In the remaining two cases there was a competing referent with the
same features as the correct antecedent in the context, but this individual was in
both cases never salient in the discourse. In the example taken from Fox, example
(25) given earlier, the clue to antecedent identification would be the information
that the anaphoric subject was going to the hospital, and because only one
discourse participant is talked of as going to the hospital earlier, this should be
sufficient to identify the earlier context where the earlier mentioned grandmother
appears in order to retrieve it as an antecedent.
Walker’s (1996) results put into doubt the assumption that hierarchical
discourse structure plays the key role in limiting the search space for antecedents of
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