Identity Examples given for this class are:
21.
a)I met a man. The man told me a story.
b)I ran two miles. The run did me good.
He also gives as an example of direct reference (identity) the following:
22.Her house was large. The size surprised me.
I n (24) shown above, the term “direct” refers to the fact that the size (of the house) has already been mentioned (when describing it as being large). This notion of “identity” does not seem to conform to a notion of co-referentiality. In other approaches (see Strand, below, for instance) the reference the size is seen as associated to the noun the house rather than to the adjective large.
P ronominalization s These are cases in which the description uses only a subset of the properties that characterise a previously mentioned entity. We have a continuum: an elderly gentleman, the elderly gentleman, the elderly man, the gentleman, the man, the oldster, the adult, the person, he. The semantic relations of synonymy and hypernymy belong to this class together with the use of pronouns.
23.I met an elderly gentleman. The man told me a story.
E pithets This class contains those cases in which the bridging reference adds new information to the entity referred to.
24.I met a man. The bastard stole my money.
I n the example above (26) the antecedent for the bastard is the entity referred to by a man---that entity is also a bastard, but this information is new. The extra information is concerned with the speaker's opinion of the facts rather than the facts themselves.
S et membership In this class are those cases in which the description picks out an element from a previously mentioned set.
25.
a)I met two people. The woman told me a story.
b)I swung three times. The first swing missed by a mile.
Indirect reference by association
Clark, like the other authors we have discussed, notes that the description may not have a directly mentioned antecedent but one that is closely related to it. He notes that the associated information varies in its predictability from absolutely necessary to quite unnecessary, distinguishing three levels:
Necessary parts
26.
a)I entered the room. The ceiling was high.
I entered the room. The size was overwhelming.
Probable parts
27.
a)I entered the room. The windows looked out to the bay.
b)I went shopping. The walk did me good.
Inducible parts
28.I entered the room. The chandeliers sparkled brightly.
I ndirect reference by characterisation
A description may characterise a role played in an event or circumstance mentioned earlier. Clark presents a variety of such cases:
N ecessary roles
29.
a)John was murdered. The murderer got away.
b)I went shopping. The time I started was 3 p.m.
Optional roles
30.
a)John died. The murderer got away.
b)John was murdered. The knife lay nearby.
Clark observes that often noun phrases contain as part of their specification the information of how they relate to other events as in the person who murdered John, the knife with which it was done. Adjectives can carry out a characterising function too, as in the guilty party got away. He says that what adjectives, relative clauses and derived nouns (such as murderer) do is to pick out the role the intended antecedent plays in the previously mentioned events. Clark comments that sometimes the distinctions between parts and roles may be impossible to maintain.
Relations of reasons, causes and consequences As we have already seen, the antecedent of a bridging description is often an event and not an object and may give the reason for, cause of, or consequence of other events or states. Clark's examples for this class do not include the use of definite descriptions. We present as an example (33).
31.An earthquake... The suffering people are going through...
7. Sidner’s co-specification and specification rules
Sidner (1979) lists several ways (rules) in which a full definite NP may derive its co-specification or specification from the focus (a list of the most salient elements in the discourse, i.e., what the discourse is about). The focus for definite description interpretation includes:
the current focus, the most salient element in the last sentence according to a set of rules proposed by Sidner;
the potential focus, elements in the last sentence other than the current focus;
the stacked focus, the set of current foci previous to the last sentence (It is not clear if the Actor Focus Stack should be also considered for definite description interpretation.). Sidner presents several algorithms that work together to resolve anaphoric NPs and to keep track of the discourse focus. Her algorithms rely on a semantic network that encodes elements and their associations, provides links expressing their general class, and provides for inheritance of associations. The rules listed by Sidner are the following: Explicit Backwards Co-specification
Co-specification 1 Definite description and focus have the same head and no new information is introduced by the definite.
32.A small office... The office
S he mentions the difficulty imposed by definites with new information since it is not clear whether they co-specify with the focus or refer to a new discourse element. Clark, however, has observed that a definite description may specify or add new information to the antecedent (epithet).
C o-specification 2 The definite's head noun lexically generalises that of the focus and has no restrictive postmodifiers.
33. A ferret... The animal...
S he claims that generalisations accompanied by restrictive relative post-nominal modifiers fail to co-specify with the focus. This class is similar to Clark's pronominalization.
I mplicit Backwards Specification
H ere the definite does not co-specify with the focus. It is said, instead, to specify an element c losely related to the focus by association. She proposes the following restriction on the elements available for the computation of specifications: NPs in the stacked foci are not considered as focus for these cases. Sidner says that stacked foci do not seem to be used in this way perhaps because the additional processing time would not make it possible to extend the judgements to the focus stack. This means that a definite description can only specify an element in the previous sentence.
A ssociated Specification The definite names an entity associated with the focus directly or by inheritance on the network hierarchy. The inferences made in the association involve common sense knowledge about the world.
34.Meeting... The participants...
I nferred Specification As above but the inferences involve hearers' suppositions that are not necessarily true. (This class may include a broad range of relations.)
35.The dead heiress... The murderer
S et-element Specification The focus is a set, the description is singular and has the same head as the focus and additional modifiers whose role is to determine which member of the set is being discussed.
36.There were clowns performing in the square. The clown with the unicycle did a
fantastic stunt.
S idner comments that these cases are easier to distinguish than other specifications, because the head noun is the singular form of the noun phrase represented in the focus. There are, however, set-element sequences such as a couple...the woman which would involve knowledge of set-element relations as well as generalisation and/or associations. It is not clear whether the associated specification or inferred specification rules would handle cases like this.
C omputed Specification The specification of the description may be computed from that of the focus. The description has an ordinal modifier, the same head as the focus and no relative clause modifiers. Sidner observes that descriptions containing full relatives (such as the first person to sail to America) use the relative clause and not the focus to compute its specification.
