with our taxonomy. We will now discuss possible reasons for this difference.
First of all, we think there are some problems with their approach which make a direct comparison difficult. For one, they are not very explicit on the criteria they used for annotation: they do not mention the problem of overlaps and how they influenced their data, i.e. whether they regarded constituents that were separated from the original utterance as shown above in (96-a) asNSUs or not. In general, they do not offer in the paper a clear definition of what they classified in the first place, beyond the statement that “dialogue is full of intuitively complete utterances that are not sentential”; and they do not make a distinction similar to ours between ‘message-type NSUs’ and ‘non-message-typeNSUs’. From the fact that they have a class Acknowledgements which include “utterances like ‘okay’, ‘yes’ and ‘mm’
that signal that the previous utterance was understood” (p.17) one can conclude that they used what we called the wide-definition of fragmenthood above.29If that is the case, however, then their numbers are significantly lower than ours: remember that if we include what we called ‘non-message-typeNSUs, we got 19.4% for the same corpus. This can presumably be partially explained by the fact that in some of the files they included (namely in the formal interviews) such kinds of utterances were not transcribed,30 but it is difficult to say whether this accounts for the whole difference.
This vagueness about the data makes it difficult to interpret their 99.5% coverage. Perhaps more import-antly, however, their classes are rather surface-oriented and hence not as much contextual information is needed for the classification task as with our taxonomy. This is an advantage for annotation, and could help to explain why they achieved greater coverage in the classification task than we did. But a surface-oriented approach to defining speech acts is a hindrance for formalising the resolution of fragments, as we will argue below in Section 2.4.
2.2.4.4 Conclusions
We believe that this study has shown that our taxonomy offers a satisfactory coverage of the data, and thus forms a good starting point from which a formalisation can proceed without the danger of loosing sight of the actual data.
has been performed with the fragment, or at least not in the sense that the speech act type uniquely determines it; we will see later that the semantics of the speech act does indeed have an influence.
What we deliberately haven’t said above is what kind of material from context and fragment has to be combined to arrive at the resolution of the fragment. For resolution-via-inference cases, this should be relatively clear: since the material coming from the fragment has to form the basis of an inferential process that might have to take into account extra-linguistic knowledge sources like world knowledge or plans, it seems that both the starting point and the result of this process will clearly be a semantic representation. Or to put it differently, it seems that the process is best defined on logical formulae, rather than on syntactic structures.31 The question how res-via-id fragments are resolved, i.e. what is actually supposed to be ‘identical’ in these cases, however, is less easily answered, and will occupy us for much of the remainder of the thesis. In the rest of this section, we will give a preview of that discussion; we will go into more detail in Chapter 4, where we discuss Morgan’s (1973) purely syntactic approach, and in Chapter 5, where we discuss a grammar-based approach that strives to mix a semantic with a syntactic approach.
The examples of res-via-id fragments we have seen so far seem to be compatible with both syntactic and semantic approaches. A syntactic approach for example could work by copying over bits of the question to the fragmental answer, to (re-)construct a syntactic structure for the resolved fragment which is then interpreted.32 In such an approach, the material that is supposed to be identical inαandβis syntactic structure. A semantic approach on the other hand could work by combining the appropriate semantic material fromαandβto result in a semantic representation of the intended meaning.
As we will see in our discussion on Morgan’s (1973) approach, however, there are examples that seems to disfavour a syntactic resolution. In example (101), for instance, the syntactic structure corresponding to “heihimself likes Johni” is not well-formed, whereas the fragment (101-b) is.33
(101) a. A: Who likes Peter?
b. B: He himself.
*Heihimself likes Peteri.
Another example of this kind is the following, where similarly a binding constraint is violated:
(102) A: Who does Sandy think John likes.
B: Herself.
*Sandyithinks John likes herselfi.
31Note that we talk of processes here just for convenience; the actual definition of resolution we give in Chapter 8 will be specified declaratively.
32We will discuss the distinction between syntactic and semantic approaches to ellipsis in general in Chapter 3 and to fragments in particular in Chapter 4.
33Similar examples are discussed in (Barton 1990) and (Ginzburg 1999b).
Nevertheless, this cannot be taken as evidence that a purely semantic approach would do better, as (Ginzburg 1999b) pointed out.34 Why this is so can be shown in English with examples like (103) and (104). The preposition in (103), being a verb particle, is normally seen to be fulfilling only a syntactic role, and hence is not represented in the logical form (cf. e.g. (Pollard & Sag 1994, p.25)). This example, however, suggests that the questions license the use of the preposition in the answer: in (103-a), only the same preposition as in the question is allowed; one cannot use the (similarly semantically null) verb particle “of”. In (103-b) no semantically null preposition (i.e. preposition as a verb particle) is felicitous at all. If the presence of these verb particles, which are semantically empty, is not recorded in the logical form of either question or answer, then we can conclude from this that at least this kind of syntactic information has to be preserved in the representation of the context.
(103) a. A: On whom can Mary always rely?
B: On Peter. /#Of Peter.
b. A: Who does Mary like?
B: # On Peter.
Similarly, the grammatical idiosyncrasy of the verbs “make” and “do” in example (104) (they require an infinite verb or a base-form verb in their argument VP, respectively) seems to be ‘transmitted’ to the short-answer.35 A semantic explanation of this fact would have to claim that the VPs in these short-answers are of different semantic type; a claim that presumably would lead to a fine-grainedness in semantic types that could cause problems elsewhere in the grammar.
(104) a. A: What did he make you do? B: Sing. / #To sing.
b. A: What did he force you to do? B: To sing.
Examples from case-rich languages like German can reinforce the observation even more. In the fol-lowing example, it seems to be the case that the (quite idiosyncratic) case-assignment by the verb to its arguments is also effective across the sentence boundary.
(105) A: Wemdat hast Du geschmeichelt? B: [Dem Mann]dat. A: Who did you flatter? B: The man.
A: Wenacchast Du gelobt? B: [Den Mann]acc. A: Who did you praise? B: The man.
(Ginzburg 1999b) and subsequent papers only investigate this syntactic influence for short answers to
34(Ginzburg 1999b) does not discuss ‘why’-questions, and does not make a distinction comparable to ours between resolution-via-inference and resolution-via-identity. Indeed, as we will explain in 5, his approach seems for principled reasons to be only applicable to the latter.
35We will discuss later the fact that the complementizer in (104-b) does actually seem to be optional.
complement questions and certain types of fragmental questions, but as the following examples show, the situation seems to be similar for our whole class of res-via-id fragments.
(106) a. He made him sing.
Sing a whole aria(, to be precise.) / #to sing a whole aria.
b. He forced him to sing.
To sing a whole aria(, to be precise.)
(107) A: [Der Lehrer]nomgab [dem Sch¨uler]dat[den Hammer]acc. The teacher gave the student the hammer.
a. B: [Der Mathelehrer]nom(, um genau zu sein).
The maths teacher(, to be precise).
b. B: [Dem Klassensprecher]dat(, um genau zu sein).
The head of class(, to be precise).
c. B: [Den neuen /0]acc(, um genau zu sein).
The new (one)(, to be precise).
Ginzburg & Sag (2001) explain this data for short-answers by stipulating a requirement of an identity of category between wh-phrase and the phrase constituting the fragment (the exact technical details of how they do this are discussed in detail in Chapter 5.).36In their approach, the pattern observed in (103-a) for example would be explained by the requirement of categorial identity between “on whom” / “of whom”
(aPP[on] /PP[of], respectively) and “on Peter” / “of Peter” (similarly aPP[on] /PP[of]).37(103-b) would be ruled out, since the wh-phrase is anNP, and the short-answer aPP. Note that their approach does not require full syntactic reconstruction, but is restricted to exactly this amount of syntactic information.
We highlight some problems with this approach here. First, it seems that words from certain classes can be ‘dropped’ in short-answers. For example, questions where the wh-phrase is a PP, like those in (103) above and in (108) below, can nevertheless be answered felicitously with NP-fragments, as shown in (108-a).
(108) a. A: On whom did Mary rely?
B: Sandy. / On Sandy.
b. A: On what did you put the book?
B: The table. / On the table.
Similarly, the complementizer “to” from the VP-answer in (104-b) above seems to be dispensable, as
36They only offer an approach for some of the speech-acts we have classified above, but presumably their approach could be extended to deal with the observations for other res-via-id cases of fragments in a similar way by stipulating categorial identity.
37They do not explicitly deal with prepositional phrases, but this is what follows from the examples given in their paper.
(109) shows.38
(109) A: What did he force you to do?
B: Sing. / To sing.
Moreover, as we have seen above when we looked at elaborations, res-via-id fragments do not always replace an element inα(where this element would be the antecedent for Ginzburg’s parallelism con-straint). The examples in (36) above, two of which are repeated here as (110), have shown that also non-realised optional arguments of elements ofαcan be elaborated with fragmental utterances.
(110) a. A: Peter was reading when I saw him.
A book about Montague semantics(, to be precise).
b. A: Die Verleihung war spektakul¨ar.
[Des Oskars]gen, meine ich.
(The handing over of the award was spectacular. Of the Oscar, I mean.)
Examples like this suggest that it is not directly the syntactic category of an element ofαthat is im-portant, but rather the syntactic constraint of an element ofαon its complements, be that a verb, as in (110-a) above, or a noun, as in (110). Note also that arguably we even need the requirements for a related verb, namely the transitive rather than the intransitive version of ‘read’, in (110-a).
As we said, we will return to the question of how this data that apparently pulls in different directions—
contra syntactic, but also contra semantic reconstruction—should best be analysed. For now, this closes our introduction of our taxonomy, and we conclude by comparing it to ones that can be found in the literature.