SOME FACTS ABOUT CENTERS, INDEXICALS, AND DEMONSTRATIVES 
Rebecca J. Passonneau 
Columbia University 
450 Computer Science Bldg. 
New York, New York 10027, U.S.A 
becky@cs.columbia.edu 
ABSTRACT 1 
Certain pronoun contexts are argued to establish a 
local center (LC), i.e., a conventionalized indexical 
similar to lst/2nd pers. pronouns. Demonstrative 
pronouns, also indexicals, are shown to access en- 
tities that are not LCs because they lack discourse 
relevance or because they are not yet in the uni- 
verse of discourse. 
1 Introduction 
Referring expressions in discourse are multifunc- 
tional and dual-faced. Besides functioning to spec- 
ify referents, they also indicate the status of their 
referents in the evolving discourse model, such as 
the informational status of being given or new 
\[Pri81\], or maintain the attentional status of be- 
ing in focus \[Sid83\] \[Gro77\]. They are dual-faced 
in that the surface form of a referring expression 
is constrained by the prior discourse context, and 
then increments the context, serving to constrain 
subsequent utterances \[Isa75\]. As a consequence 
of this latter property, the communicative effect of 
many referring forms, especially pronouns, is rel- 
ative to specific types of discourse contexts. The 
discourse reference functions of a few types of pro- 
nouns are examined, taking into account their mul- 
tifunctionality and their dual nature, in order to 
clarify their processing requirements in dialogic 
natural language systems. In particular, a compar- 
ison of the conversational usage of it with two types 
of indexical pronouns indicates that certain uses of 
it, referred to as local centering, resemble what Ka- 
plan \[Kap89\] refers to as pure indexicals. Several 
functions of lhat are also identified and shown to 
contrast with local centering with respect to their 
preconditions and effects. 
Third person, definite (3d) pronouns contrast 
with indexical pronouns because the referents of 
the former are arbitrary, and must be actively es- 
tablished as part of the current universe of dis- 
course in order for the intended referent to be 
1 This paper was written under the support of DARPA 
grant N000039-84-C-0165 and NSF grant IRT-84-51438. I 
am grateful to Kathy McKeown for her generous support. 
identified. In contrast, the referents of index- 
icals such as I and you (i.e., the speaker and 
addressee) are necessary components of the dis- 
course circumstances. 2 Indexical pronouns can 
be further classified into pure indexicals versus 
demonstratives, 8 depending on how the current dis- 
course circumstances provide their referents. The 
referent of a pure indexical is fully determined by 
the semantic rules and a context, which together 
pick out a unique referent for each use. Thus I 
refers to the person who utters it (assuming that I 
is used to refer). A pure indexical cannot refer to 
alternative entities, nor can any other expression 
pick out the relevant entity via the same type of 
referring function. Pure indexicals do not add en- 
tities to a context, or change the attentional status 
of their referents. 
In contrast, the referent of a demonstrative pro- 
noun is not completely determined by the context 
plus the semantic rules. An accompanying demon- 
stration is required, such as a physical or vocal 
gesture to something in the immediate discourse 
circumstances. Further, demonstratives can refer 
to anything in the context that can be demon- 
strated. In the cases of discourse deixis discussed by 
Webber \[Web90\], e.g., demonstrative pronouns are 
used to refer to discourse segments. Webber notes 
that in these cases, the demonstration consists in 
the intention to refer signalled by the use of the 
demonstrative, plus the semantics of the contain- 
ing clause, plus attentional constraints on which 
discourse segments can be demonstrated. 4 Thus, 
3d pronouns, pure indexical pronouns, and demon- 
stratives all differ with respect to the set of con- 
textual elements that are available referents, and 
the manner in which the referent is related to the 
referring expression. Investigating their distinct 
discourse functions leads to extensions to the tri- 
2The term indexical includes devices whose meaning per- 
talns to the time, the place and the perceived environment of 
a discourse context, e.g., tense, deictic adverbs (here, there) 
and deictic pronouns (this, that) \[Pei35\]. 
3The view of indexicals presented here is largely drawn 
from Kaplan \[Kap89\]. 
4Webber \[Weh90\] argues that only segments on the right 
frontier are available referents. 
63 
partite discourse model of attentional state, inten- 
tional structure and segmental structure proposed 
by Grosz and Sidner \[GS86\]. 5 
The data presented here come from a set of dia- 
logic interviews, originally described in \[Sch85\] (cf. 
also \[PasS9\]). The methodology, fully described in 
\[Pas90\], primarily involves the examination of lin- 
guistic choices that are in principle independent, 
but which are found to co-vary significantly of- 
ten. Such co-variation is presumed to serve commu- 
nicative functions that discourse processing models 
need to replicate and explain. It should be remem- 
bered that the patterns of co-variation •described 
here represent pragmatically significant usage pat- 
terns, rather than obligatory ones. 
2 Local Center 
In previous work, I presented the results of an anal- 
ysis of the distribution of occurrences of it and 
that having explicit antecedents in conversational 
data from 4 interviews, involving 5 different speak- 
ers (g = 678) \[Pas89\]. The two pronouns have 
similar syntactic contexts of occurrence thus dif- 
ferences in their distribution are pragmatic in na- 
ture, and stem primarily from the semantic con- 
trast of demonstrativity with non-demonstrativity. 
Previously, I had noted that the data supported 
the centering rule (CR) \[GJW83\] and the property 
sharing principle (PSP) \[Kam86\]. A review of the 
assumptions of the centering model, and of the con- 
versational data, argues for an alternative view. In 
this section I reinterpret the results as establishing 
a distinct attentional state, local center. I explain 
the two property sharing patterns of Kameyama's 
PSP (subject and non-subject, \[Kam86\]) with re- 
spect to local center, and discuss the similarity be- 
tween local centers and pure indexicals. Finally, I 
discuss the relation • of local centering to intentional 
and segmental structure. 
According to the centering model, every utter- 
ance has a backward-looking center---the currently 
most salient entity, but it need not be overtly men- 
tioned in the current utterance \[GJW83\]. The cen- 
tering rule (CK) \[GJW83\], in combination with the 
property-sharing principle (PSP) \[Kam86\], predict 
certain preferred surface choices for maintaining 
the backward-looking center (Cb). The CR says 
that when the same Cb is maintained in a new ut- 
terance, it is likely to be expressed by ;a (3d) pro- 
noun \[GJW83\]. The PSP says that when 3d pro- 
nouns realize the Cb in adjacent utterances, they 
. 5 The term segmental structure is used in place of their 
linguistic structure. 
FA and GR Lex. Choice and Gr of N2 
of N1 SUB I Non-SUB 
I that it I that it l 
Cell No. 1 2 3 
147 31 39 19 
ProsvB 96.0 48.7 48.7 42.4 
27.1 6.4 1.9 12.9 
Cell No. 5 6 7 8 
37 21 34 14 
Pro,~on-SvB 43.1 21.9 21.9 19.1 
.9 .0 6.7 1.3 
Cell No. 9 10 11 1P 
18 6 11 10 
NPsuB 18.3 9.3 9.3 8.1 
.0 1.1 .3 .1 
Cell No. 13 14 15 16 
43 33 36 45 
NP,~o.-SUB 63.9 32.4 32.4 28.2 
6.8 .0 .4 I0.0 
Cell No, 17 18 19 20 
8 5 1 1 
OTHsuB 6.1 3.1 3.1 2.7 
.6 1.2 1.4 1.1 
Cell No. PI PP 23 2,~ 
23 44 19 33 
OTH,on-SvB 48.4 24.6 24.6 21.4 
13.3 15.3 1.3 6.3 
Table x-Square 116.3 
Probability 0.00001 
Table 1: Effects of form and grammatical role of 
antecedents on pronoun choice, with observed fre- 
quency, expected frequency, and x-squares for each 
cell (individual cells are numbered for convenient 
• reference) 
should both be subjects (canonical center reten- 
tion) or both not subjects (non-canonical center 
retention) \[Kam86\]. Given that the Cb can poten- 
tially be realized in non-preferred ways, that the 
Cb may change, or that it may be unexpressed, Cb 
has many possible surface realizations within a lo- 
cal discourse context of two s-adjacent utterances. 6 
The distinct effects of alternate realizations of Cb 
on segmental structure and intentional structure 
have not been explored. Also, since the centering 
model focusses on 3d pronouns, no claims are made 
regarding the relation of indexical pronouns to the 
discourse model. 
The empirical results presented in \[Pas89\] 
showed that two features of the utterances contain- 
ing a pronoun and its antecedent were extremely 
6I usethe somewhat awkward term s-adjacen$ to connote 
adjacency with respect to a containing segment, an impor- 
tant aspect of the Grosz-Sidner model; thus two s-adjacent 
utterances need not be literally adjacent. 
64 
predictive of lexical choice between it and that: the 
form of the antecedent (FA), and the grammati- 
cal role (GR) of both expressions. The best clas- 
sifications were where FA had the three values-- 
pronominal antecedent (PRO), full NP antecedent 
(NP), and other (OTH)--and where GR had the 
two values---subject (SUB) and non-subject (non- 
SUB). No other classifications of FA or GR were as 
predictive/ It is crucial to note that these classi- 
fications were the minimal set that still preserved 
the distinctiveness of the distributions. Seven other 
surface features had previously been found to be 
non-predictive \[Sch85\]. s Table 1 shows a very 
strong correlation (p -- .01%) 9 between the form 
and GR of the antecendent (N1) and the lexical 
choice and GR of the co-specifying pronoun (N2). 
Exactly 2 contexts selected for it, as shown by the 
combination of the high cell X2s, and the low val- 
ues for expected frequency, which together indi- 
cate that the observed frequency was significantly 
high. These 2 contexts were where the antecedent 
was PRO and where both expressions maintained 
the same GR value (cells 1, 7; PROGR, by itaR~). 
Of these 2, the more significant context, and in- 
deed the most significant context in the whole ta- 
ble, was where the antecedent was PROGRsvv (cell 
X 2 = 27.1). This is also the context type where 
the demonstrative was predicted not to occur (i.e., 
where the antecedent was PROscrBj; cells 2,4), 
indicating a functional opposition between it and 
that. l° Most of the cases of the PRO antecedents 
consisted of occurrences of it (65%), indicating that 
N1 and N2 often have the same form: it. Previ- 
ously unreported data bear on the likelihood that 
adjacent tokens of it will co-specify. An analy- 
sis of all adjacent utterance pairs where each con- 
tained at least one token of referential it revealed 
that 30% were cases where both were subjects, of 
which 90% co-specified. In contrast, it occurred 
with opposing GR values 20% of the time, with 
comparatively fewer instances where both tokens 
co-specified (65%). 
In sum, the data show that given ar~ occurrence 
of it with an antecedent, the antecedent is likely 
rCf. \[Sch85\] \[Sch84\] for how it was determined that these 
were the maximally predictive classifications. 
sViz., speaker alternation, clause type (main or subor- 
dinate), parallelism, and various measures of distance be- 
tween pronoun and antecedent (e.g., intervening utterances, 
intervening referents, syntactic depth). Note also that no 
significant variation with respect to FA and (lit was found 
across individual speakers or conversations. 
9Note that a probability of 5~ or less is generally taken 
to be higtfly significant. 
10 The remaining 4 of the 8 PRO antecedent contexts were 
non-predictive. 
to be it, the GR of both expressions is likely to be 
SUB, and in either case (SUB or non-SUB), they 
will have the same GR value. The opposing GR 
pattern is not predictive (where GR of N1 is not 
the same as GR of N2). Nor is it predicted to oc- 
cur with an antecedent NP, and is predicted not 
to occur with an antecedent OTH. The 2 contexts 
singled out here indicate that it is a likely form for 
re-referring to a known, given entity--because the 
antecedent is PRO. Conversely, successive occur- 
rences of it in Ui and Ui+I generally co-specify if 
they have the same GR. The entity referred to by 
it in these two patterns is called a local center. The 
following local center establishment (LCE) rule en- 
capsulates how a local center is anticipated and 
maintained, both for discourse understanding (.4) 
and generation (B). 
A: Recognizing a Local Center: Two s- 
adjacent utterances U1 and U2 establish en- 
tity £ as a local center only if U1 contains a 
3ds pronoun N1 referring to g, U2 contains 
a co-specifying 3ds pronoun N2, and N1 and 
N2 are both subjects or both non-subjects. 
In the canonical case, both are subjects. 
B: Generating a Local Center: To estab- 
lish g as a local center in a pair of s-adjacent 
utterances U1 and U2, use an expression of 
type N to refer to g in both utterances where 
each token, N1 and N2, is a 3ds pronoun, and 
each is the subject of its clause or each is not 
the subject of its clause. In the canonical 
case, both should be subjects. (Precondition: 
To establish an entity ,~ as a local center, C 
must be in the current focus space, and it 
must be possible to refer to it with a 3ds pro- 
noun.) 
Recall from §1 that the process of interpreting 
a pure index requires no search or inference, but 
depends only on how the discourse circumstances 
are currently construed. The semantic value of a 
pure index is a contextual attribute--e.g., current 
speaker--that must have a particular referential 
value whenever an utterance occurs. In many ways, 
a pronoun fulfilling the LC function is like a pure in- 
dex. Discourse initially, there is no LC, because the 
LCE rule depends minimally on an utterance pair. 
But for any utterance pair where the LCE rule has 
applied, there will be a discourse entity--a com- 
ponent of the speech situation--that is by default 
indexed to the use of subsequent referring expres- 
sions with the right lexico-grammatical properties. 
An LC conforms to the characteristics of a pure in- 
dexical in that it becomes established as a transient 
attribute of the speech situation analogous to the 
essential attribute current speaker. The relation 
of the referent to the referring expression is one- 
65 
to-one; no other referents are candidate LCs, and 
no other form can access the LC. The processing 
mechanism for interpreting subsequent expressions 
conforming to the LCE rule is highly constrained. 
It is analogous to, although not identical with, that 
for pure indexicals. The difference is that the lo- 
cal center is not lexicalized, but rather, must be 
established and maintained by certain conventions 
of usage. CPs can choose not to establish a LC, or 
can choose not to maintain it. 11 
Kameyama \[Kam86\] proposed canonical and 
non-canonical property sharing patterns, but did 
not discuss what governs the choice between them. 
Here it is suggested that the non-canonical LC pat- 
tern, illustrated in 1), results from the interac- 
tion of two distinct pragmatic effects. In the non- 
canonical LC contexts, where the LC was realized 
by non-SUB, the grammatical subjects were most 
often 1st or 2nd person pronouns. 12 This data con- 
forms to an empirically supported proposal made 
by Givon and others \[Giv76\] \[Li76\] that preferred 
subjects are animate rather than inanimate, defi- 
nite rather than indefinite, pronouns rather than 
full NPs, and 1st or 2nd person rather than 3rd 
person, due to the facts that in English, gram- 
matical subjects often express discourse topics (cf. 
also IF J84\]), that people prefer to talk about them- 
selves and other people, and that discourse topics 
are given. The interviews examined here were in- 
tentionaUy biased towards the discussion of non- 
animate entities, is But Givon's subject hierarchy 
predicts that, given a non-animate and an animate 
entity in a single utterance, the latter will more of- 
ten occur as the subject. Since every matrix-clause 
utterance can have only one subject, there is po- 
tential competition for the subject role. The data 
show that when SUB, reserved by the LCE rule for 
establishing a local center, is pre-empted by a Ist or 
2nd person pronoun, it is still possible for LC to be 
realized by alternate means, namely by sharing of 
non-SUB. Thus the sharing of the GR value across 
utterances is a defining characteristic, as noted by 
Kameyama \[Kam86\]. The non-canonical LC con- 
11 That CPs often do maintain an LC is borne out by data 
pertaining to cohesive chains, a succession of utterance pairs 
in which every utterance contains a co-speclfying pronoun 
token. There were 101 cohesive chains in the interview data, 
ranging in length from 2 to 13 successive utterances, con- 
talning 506 pronouns, the majority of which involved LC 
contexts; cf. \[Pas90\]. 
12The two next most likely possibilities were an sallmate 
full NP, or a non-referential pleonastic element, e.g., existen- 
tial there. After that, there was a very small heterogeneous 
category. Note: subject always refers to a surface grammat- 
ical function. 
13E.g., college courses, degree requirements, career op- 
tions, resttm~s, and so on. 
figuration results from an interaction between two 
separate organizing forces: the LC status of the 3d 
pronoun referent, and the attentional prominence 
of the speaker and hearer. 
(1) 
Sla: 
Slb: 
S1¢: 
Sxd: 
Sle: 
S2a: 
S2b: 
$3 : 
I don't have the mental capacity 
to handle uh what I would like to teach 
which'd be philosophy 
or history at U of C 
uh with that level students um 
maybe with time and experience 
I'll gain it 
but I don't have it now 
In example 1), the utterance pair $2 and $3 
share a 1st person subject and a non-canonical lo- 
cal center. 14 In this case, the centering model can- 
not provide a principled answer to the question of 
whether the speaker--the grammatical subject-- 
or the speaker's 'mental capacity'--referred to by 
successive 3d pronoun direct objects--is the cur- 
rent center. In the model proposed here, $2 and S~ 
establish 'mental capacity' as a local center, an at- 
tentional status for regulating the generation and 
production of 3ds pronouns, and the question of 
which entity is more salient does not arise. But lo- 
cal centering does seem to have a secondary func- 
tion pertaining to the linkage between utterances 
at the level of intentional and segmental structure. 
In addition to sharing a default referent, clauses 
containing LC pronouns are often semantically 
alike in other ways. In an initial attempt to test 
for this similarity, utterance pairs with PRO an- 
tecedents were classified into those that did and 
did not conform to the LCE rule. No other con- 
texts were examined because contexts with OTH 
and NP antecedents were presumed to be even less 
like LC contexts. These utterance pairs were sorted 
into cases where the lexical root of the matrix verb 
in both clauses was identical (i.e., the verb of which 
the pronoun was an argument), but where the ut- 
terances were not verbatim repetitions. 15 The re- 
sults were that 30% of the LC contexts had the 
same verb, but only 11% of contexts differing from 
LC in that N2 was that instead of it. None of 
the contexts with opposing GI~ values for the two 
pronouns had the same verb, which is not surpris- 
ing given that for most verbs, each argument po- 
sition has a very distinct semantic role. In sum, 
by maintaining an LC and the same lexical verb, 
14In interview excerpts, S is the student and C the coun- 
selor. Feedback cues from the addressee indicating contin- 
ued attention (e.g., uhhuh) have been omitted. 
15In copular clauses, the be-complements were compared 
instead of the verb; ellipsis was counted as identity. 
the speaker continues to predicate the same type 
of information about the same entity. This pre- 
sumably serves as a cue that the speaker main- 
tains a common Discourse Segment Purpose (DSP, 
\[GS86\]) throughout both utterances--to convey in- 
formation about the local center with respect to 
the state of affairs conveyed by the verb. Insofar as 
local centering pertains to segment continuation, 
or to relating a new utterance to the DSP of a 
preceding utterance, a discourse plan to continue 
the current DSP need not refer directly to the sur- 
face grammatical choices which reflect that plan, 
but only to the current status of LC. If there is a 
current LC, then maintaining it would reflect the 
speaker's intention for the next utterance to con- 
tinue the same DSP as the prior utterance. 
The data assembled here indicate that local cen- 
tering not only constrains the interpretation of cer- 
tain pronouns, but also conveys the inter-utterance 
relevance of locally centered entities in a larger dis- 
course segment, or in the discourse as a whole. 
However, most of the entities referred to in the con- 
texts represented in Table I are not LCs. Logically, 
that means they can fall into several classes: e.g., 
entities that are former or potential LCs because 
they are in the universe of discourse and are rele- 
vant to a former or future DSP; entities that are 
in the universe of discourse but are not LCs be- 
cause they are peripheral to the current DSP; and 
finally, entities that are not yet in the universe of 
discourse. The next section will illustrate how the 
demonstrative picks out entities in the latter two 
classes. 
3 New Entities, Anti-centers, 
and Non Entities 
The results presented in the preceding section in: 
dicate that referential it has different discourse ef- 
fects, depending on its grammatical role, and on 
various properties of its antecedent, which in turn 
depend on the status of the referent in the discourse 
context. Just as local centering is only one dis- 
course referring function that it participates in, it 
will be seen that there are several referring func- 
tions the demonstrative participates in, each with 
distinct preconditions and effects. Although pro- 
nouns are often thought of as identifying topical 
entities, that is not necessarily the case. English 
has a relatively impoverished inventory of pronouns 
in comparison to the Bantu language Chich~wa, 
which has two sets of definite pronouns, one of 
which is morphologically incorporated into the verb 
stem, and the other of which consists of indepen- 
NP Antecedent IT THAT 
Given 78 17 
Not Given 31 71 
Probability " \] , .0001 
Table 2: Givenness and Lexical Choice of Pronoun 
dent morphemes IBM87\]. is In their analysis of 
Chich~wa, Bresnan and Mchombo argue that of 
the two non-argument grammatical roles in LFG, 
WOP(ic) and fOC(us), the independent pronouns 
can only fill the FOC role, not TOP \[BM87\]. In 
their framework, no expression can simultaneously 
be TOP and FOC. x7 This is reminiscent of the 
pragmatic contrast in English between it and that 
in focus-marking constructions, as illustrated in 2a- 
b) below. That is acceptable, while it is not, as a 
syntactically focussed element: 
(2) 
a. That/*It I bought for my mother, 
but I could get another one for you. 
b. Pepper is okay, but don't add more curry. 
It's ?that/*it that makes me sneeze. 
These examples are compatible with the conver- 
sational data in the following way. If TOP and 
FOC are truly contrastive grammatical functions, 
the above examples show that that is more accept- 
able as FOC. We have seen that it is less likely 
when the antecedent is NP or OTH than when it 
is PRO, that it occurs often as SUB, and often 
with SUB antecedents. Thus it, whether fullfill- 
ing LC or not, correlates with other properties of 
discourse topics. An entity that has been referred 
to by an antecedent pronoun has already been lo- 
cated in the universe of discourse, and already has 
the informational status of given prior to the oc- 
currence of the pronoun itself, and thus is a likely 
topic. We have also seen that that is unlikely with 
PROsvB antecedents, which would correlate with 
a presumed likelihood for that to not express TOP. 
But further evidence regarding the informational 
and attentional status of the likely referents of that 
reinforces the presumed TOP/FOC contrast. 
The first case we'll look at involves NP an- 
tecedents. Table 2 shows the distribution of an- 
tecedent NPs, classifed according to whether they 
were given or not, by lexical choice of it or that. 
A referent was classified as given if it had been 
16In addition, there is a separate set of demonstrative 
pronouns. 
17More specifically, not at the same level of LFG func- 
tional clause structure. 
67 
mentioned previously, if it was closely associated 
with a previously mentioned entity (e.g., social 
worker and the social work profession), or if it was 
a commonly known individual entity whose iden- 
tity would would be known to either speaker (e.g., 
places such as New York City). The very low prob- 
ability for the X 2 of Table 2 (p = .01%) indicates 
that the tendency for that to occur with new an- 
tecedents and for it to occur with given antecedents 
is extremely significant. Further classifying the lo- 
cal utterance contexts by GR in various ways did 
not reveal any further significant distinctions. This 
result, while not counter-intuitive, is not one that 
would be obvious without looking at frequency dis- 
tributions in actual on-line discourse, since it can 
easily and naturally be used to co-specify with a 
new antecedent, or that with a given antecedent. 
Some examples from the interviews are shown in 
3-4) with the relevant pronoun token and its NP 
antecedent in boldface. They have been particu- 
larly selected to show that the occurring pronoun 
can be felicitously replaced with the opposite choice 
(shown in parentheses). 
(3) 
Cla: 
Clb: 
Clc: 
C~ : 
Ca : 
(4) 
it is the service that you give to other 
people be it as a doctor or a social 
worker a psychiatrist or a lawyer 
you have a certain expertise 
and people use that (it) 
C1 " 
C2a: 
Cab: 
Ca : 
C4 : 
I know we've had information about it 
and uh if not you can a- 
just write directly to Bryn Mawr 
and ask them about the p~ogrRm 
and see if they still have it (that) 
One way to interpret these results is that a single 
reference to a new entity is insufficient to establish 
the entity as part of the universe of discourse, given 
the processing demands of actual on-line discourse. 
In the cases where an entity is already given, but 
is referred to by a full NP rather than a pronoun 
(for whatever reason), the entity can be successfully 
reinvoked in the immediately following utterance 
by a 3ds pronoun. If the entity is new, a single prior 
mention is not in general sufficient, with respect to 
these data, to predispose the use of a 3ds pronoun 
to reinvoke it. Instead, the demonstrative functions 
to incorporate these new entities into the context. 
The demonstrative has another singular func- 
tion with NP antecedents. Table 1 singles out 
2 significant contexts where there was a full NP 
NP Ant. Relevant Not Rel. 
NPsvB/ITsvB 7 11 
NPnon-SVB/IT .... sub 17 21 
NPx/ITx 31 22 
NPsuB/THATxuB 2 3 
N P .... suB/TH AT .... sub 3:t 9 
NPx/ITx 23 17 
Table X ~ 14 
Probability .016 
Table 3: Subsequent Discourse Relevance 
antecedent (cells 13, 16). If the antecedent was 
an NPnonstrBs, there was an increased likelihood 
for thatnonstrns and a decreased likelihood for 
itst~B.r. Because itsunJ is the canonical indi- 
cator of LC, and because LCs are presumed to 
have discourse relevance (i.e., play a central role 
in the current DSP), I hypothesized that the link- 
age between an antecedent NPnonSUBJ and a co- 
specifying thatnonSUBJ served to mark the referent 
as being unlike a local center by being peripheral 
to the current DSP. This was tested by examin- 
ing how often an entity mentioned in the NP con- 
texts was mentioned later in the discourse. Table 
3 depicts the contexts in which an antecedent NP 
was followed by it or that, where GR for each was 
SUB or non-SUB, or where the GR values differed 
(X). These 6 contexts were coded for whether the 
referent was referred to again within the 10 utter- 
ances following the utterance containing the pro- 
noun. If so, the entity was coded as relevant; else 
it was non-relevant. The low probability of 1.6% 
indicates a significant correlation. The 2 cells con- 
tributing the most to the overall significance were 
for the NPno~-StrB/THATno,,-strB context, with 
non-relevant entities occurring significantly often, 
and relevant entities occurring significantly rarely. 
This evidence supports the view that the features 
of this context function to re-invoke entities while 
simultaneously signalling their peripheral status. 
The final referring function discussed here is 
where the demonstrative has an OTH antecedent. 
When N1 is OTHnonSUB (contexts 21-24), itSUB 
is unlikely (context 21), and both cases of thatsuB 
(context 22) and thatno,,-SVB (context 24) are sig- 
nificantly frequent. I will argue that these OTH 
contexts exemplify intra-textual deixis, which is 
analogous to the cases of discourse deixis stud- 
ied by Webber \[Web90\]. I refer to these cases 
as intra-textual deixis because the deictic refer- 
ence involves referents related to grammatical con- 
stituents rather than to discourse segments. 
In previous work, I pointed out that the criti- 
cal feature of the antecedent type which favors the 
lexical choice of that is syntactic, namely the dis- 
tinction between NPs with lexical noun heads and 
other types of constituents \[Sch84\]. Contexts where 
N1 is an NP whose head is a derived nominaliza- 
tion (such as the careful choice of one's words)pat- 
tern like those where the head is a lexical noun. Is 
Gerundives fall into the OTH class. Unlike NPs, 
the OTH antecedents cannot be marked for def- 
initeness: *a/*the carefully choosing one's words 
versus a/the careful choice of words. Definiteness 
is one of the means for indicating whether a refer- 
ent is presupposed to be part of the current context. 
Thus a possible difference between the interpreta- 
tion of the two types of phrases carefully choosing 
one's words and a careful choice of words would 
have to do with whether there is a discourse entity 
in the context as a consequence of the occurrence 
of the phrase itself. 
(5) 
Via: 
C:~a : 
C2b: 
Csa: 
Csb: 
C4 : 
there are some books that we 
have that talk about interviewing 
um one's called Sweaty Palms 
which I think is a great title (laugh) 
um but it talks very interestingly 
about how to go about interviewing 
and that's that's going to be important 
Another feature of OTH antecedents pertains to 
their ability to evoke specific entities into the uni- 
verse of discourse. Compare the two pronouns in 
example 5). The token of it in C~a unambiguously 
refers to the one book called Sweaty Palms. The 
referent of that in C4 is much harder to pin down. 
Does it correspond to interviewing, or to how to 
go about interviewing? This example illustrates an 
inherent vagueness in the processing of finding a 
textual referent for a demonstrative which I will 
now describe in more detail. 
Webber \[Web90\] notes that deictic reference is 
inherently ambiguous, although I prefer the term 
vague, in that vagueness connotes an underspeci- 
fled interpretation that can be given a number of 
more specific readings. Webber argues persuasively 
that deictic reference to a discourse segment is re- 
stricted to references to open segments on the right 
frontier, but that there is still an ambiguity as to 
which segment might be referred to, due to the 
recursive nature of discourse segmentation. Since 
an open segment on the right frontier may contain 
lSMixed nominals, such as the careful choosing of one's 
words, occurred too rarely to have a discriminating effect on 
contexts favoring it or that. 
within it an embedded open segment that is also on 
the right frontier, a token of the demonstrative that 
refers to a discourse segment can be ambiguous be- 
tween a more inclusive segment and a less inclusive 
one \[Web90\]. The vagueness may be eliminated if 
the context in which the deictic expression occurs 
clearly selects one of the possible readings. This 
phenomenon pertaining to deictic reference to seg- 
ments is replicated in the cases where that has an 
OTH antecedent, thus in C4 of 5), the antecedent of 
the demonstrative pronoun could be interviewing, 
or the more inclusive expression go about interview- 
ing, or the more inclusive one yet how to go about 
interviewing. I will now argue that such expres- 
sions do not in and of themselves introduce entities 
into the universe of discourse. 
(6) 
UI: 
V2: 
Us: 
I noticed that Carol insisted on 
sewing her dressesk from non-synthetic fabric. 
That's an example of how observant I am. 
And theyk always turn out beautifully. 
(7) 
UI: 
V2: 
Us: 
I noticed that Caroli insisted on 
sewing her dresses from non-synthetic fabric. 
That's an example of how observant I am. 
*That's because shei's allergic to synthetics. 
(8) 
UI: 
V2: 
U3: 
I noticed that Carol/ insisted on 
sewing her dresses from non-synthetic fabric. 
She/should try the new rayon challis. 
*That's because she's allergic to synthetics. 
The examples in 6)-8) show that entities intro- 
duced by referential NPs in U1 are still available 
for pronominal reference in Us, after an intervening 
U2. Ux introduces the referring expressions Carol 
and her dresses. Example 6) shows that the refer- 
ent of her dresses is still available in U 3 even though 
it is not mentioned in U2. Instead, Us contains 
a pronoun that refers to the fact that is asserted 
by the whole utterance U1. In contrast, the refer- 
ent of the non-nominal sentence constituent--Carol 
insisted on sewing her dresses from non-synthetic 
fabric--is not available after an intervening sen- 
tence that contains a deictic reference to a differ- 
ent non-nominal constituent, as in 7), or after an 
intervening sentence that contains a reference to a 
discourse entity mentioned in U1, as in 8). 
The preceding examples show that OTH con- 
stituents do not introduce entities into the dis- 
course context. With such antecedents, the demon- 
69 
strative does not access a pre-existing discourse en- 
tity, but rather, plays a role in a referring function 
by virtue of which a new discourse entity is added 
to the context. The occurrence of the demonstra- 
tive triggers a referring function that is constrained 
by the semantics of the demonstrative pronoun 
and its local semantic context, the antecedent, and 
other contextual considerations. The result of ap- 
plying an appropriate referring function is to in- 
crement the context with the new discourse entity 
that is found to be the referent of the demonstra- 
tive pronoun. 
This investigation has shown that a pronoun 
does not achieve discourse reference in and of it- 
self. In combination with various linguistic prop- 
erties of the prior utterance, and depending on the 
status of the referent in the context, a pronoun may 
have distinct referring functions. Although this in- 
vestigation has focussed primarily on non-animate 
pronouns, future research is expected to show that 
elements of the contrast between it and that oc- 
cur with animate 3d pronouns (e.g., he, she) since 
these pronouns have both demonstrative and non- 
demonstrative uses. 

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