File size: 66,408 Bytes
6fa4bc9
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
85
86
87
88
89
90
91
92
93
94
95
96
97
98
99
100
101
102
103
104
105
106
107
108
109
110
111
112
113
114
115
116
117
118
119
120
121
122
123
124
125
126
127
128
129
130
131
132
133
134
135
136
137
138
139
140
141
142
143
144
145
146
147
148
149
150
151
152
153
154
155
156
157
158
159
160
161
162
163
164
165
166
167
168
169
170
171
172
173
174
175
176
177
178
179
180
181
182
183
184
185
186
187
188
189
190
191
192
193
194
195
196
197
198
199
200
201
202
203
204
205
206
207
208
209
210
211
212
213
214
215
216
217
218
219
220
221
222
223
224
225
226
227
228
229
230
231
232
233
234
235
236
237
238
239
240
241
242
243
244
245
246
247
248
249
250
251
252
253
254
255
256
257
258
259
260
261
262
263
264
265
266
267
268
269
270
271
272
273
274
275
276
277
278
279
280
281
282
283
284
285
286
287
288
289
290
291
292
293
294
295
296
297
298
299
300
301
302
303
304
305
306
307
308
309
310
311
312
313
314
315
316
317
318
319
320
321
322
323
324
325
326
327
328
329
330
331
332
333
334
335
336
337
338
339
340
341
342
343
344
345
346
347
348
349
350
351
352
353
354
355
356
357
358
359
360
361
362
363
364
365
366
367
368
369
370
371
372
373
374
375
376
377
378
379
380
381
382
383
384
385
386
387
388
389
390
391
392
393
394
395
396
397
398
399
400
401
402
403
404
405
406
407
408
409
410
411
412
413
414
415
416
417
418
419
420
421
422
423
424
425
426
427
428
429
430
431
432
433
434
435
436
437
438
439
440
441
442
443
444
445
446
447
448
449
450
451
452
453
454
455
456
457
458
459
460
461
462
463
464
465
466
467
468
469
470
471
472
473
474
475
476
477
478
479
480
481
482
483
484
485
486
487
488
489
490
491
492
493
494
495
496
497
498
499
500
501
502
503
504
505
506
507
508
509
510
511
512
513
514
515
516
517
518
519
520
521
522
523
524
525
526
527
528
529
530
531
532
533
534
535
536
537
538
539
540
541
542
543
544
545
546
547
548
549
550
551
552
553
554
555
556
557
558
559
560
561
562
563
564
565
566
567
568
569
570
571
572
573
574
575
576
577
578
579
580
581
582
583
584
585
586
587
588
589
590
591
592
593
594
595
596
597
598
599
600
601
602
603
604
605
606
607
608
609
610
611
612
613
614
615
616
617
618
619
620
621
622
623
624
625
626
627
628
629
630
631
632
633
634
635
636
637
638
639
640
641
642
643
644
645
646
647
648
649
650
651
652
653
654
655
656
657
658
659
660
661
662
663
664
665
666
667
668
669
670
671
672
673
674
675
676
677
678
679
680
681
682
683
684
685
686
687
688
689
690
691
692
693
694
695
696
697
698
699
700
701
702
703
704
705
706
707
708
709
710
711
712
713
714
715
716
717
718
719
720
721
722
723
724
725
726
727
728
729
730
731
732
733
734
735
736
737
738
739
740
741
742
743
744
745
746
747
748
749
750
751
752
753
754
755
756
757
758
759
760
761
762
763
764
765
766
767
768
769
770
771
772
773
774
775
776
777
778
779
780
781
782
783
784
785
786
787
788
789
790
791
792
793
794
795
796
797
798
799
800
801
802
803
804
805
806
807
808
809
810
811
812
813
814
815
816
817
818
819
820
821
822
823
824
825
826
827
828
829
830
831
832
833
834
835
836
837
838
839
840
841
842
843
844
845
846
847
848
849
850
851
852
853
854
855
856
857
858
859
860
861
862
863
864
865
866
867
868
869
870
871
872
873
874
875
876
877
878
879
880
881
882
883
884
885
886
887
888
889
890
891
892
893
894
895
896
897
898
899
900
901
902
903
904
905
906
907
908
909
910
911
912
913
914
915
916
917
918
919
920
921
922
923
924
925
926
927
928
929
930
931
932
933
934
935
936
937
938
939
940
941
942
943
944
945
946
947
948
949
950
951
952
953
954
955
956
957
958
959
960
961
962
963
964
965
966
967
968
969
970
971
972
973
974
975
976
977
978
979
980
981
982
983
984
985
986
987
988
989
990
991
992
993
994
995
996
997
998
999
1000
1001
1002
1003
1004
1005
1006
1007
1008
1009
1010
1011
1012
1013
1014
1015
1016
1017
1018
1019
1020
1021
1022
1023
1024
1025
1026
1027
1028
1029
1030
1031
1032
1033
1034
1035
1036
1037
1038
1039
1040
1041
1042
1043
1044
1045
1046
1047
1048
1049
1050
1051
1052
1053
1054
1055
1056
1057
1058
1059
1060
1061
1062
1063
1064
1065
1066
1067
1068
1069
1070
1071
1072
1073
1074
1075
1076
1077
1078
1079
1080
1081
1082
1083
1084
1085
1086
1087
1088
1089
1090
1091
1092
1093
1094
1095
1096
1097
1098
1099
1100
1101
1102
1103
1104
1105
1106
1107
1108
1109
1110
1111
1112
1113
1114
1115
1116
1117
1118
1119
1120
1121
1122
1123
1124
1125
1126
1127
1128
1129
1130
{
    "paper_id": "P83-1007",
    "header": {
        "generated_with": "S2ORC 1.0.0",
        "date_generated": "2023-01-19T09:19:20.287326Z"
    },
    "title": "A UNIFIED ACCOUNT OF DEFINITE NOUN PHRASES IN DISCOURSE",
    "authors": [
        {
            "first": "Barbara",
            "middle": [
                "J"
            ],
            "last": "Grosz",
            "suffix": "",
            "affiliation": {
                "laboratory": "",
                "institution": "SRI International",
                "location": {
                    "settlement": "Menlo Park",
                    "region": "CA"
                }
            },
            "email": ""
        },
        {
            "first": "Aravind",
            "middle": [
                "K"
            ],
            "last": "Joshi",
            "suffix": "",
            "affiliation": {
                "laboratory": "",
                "institution": "University of Pennsylvania",
                "location": {
                    "settlement": "Philadelphia",
                    "region": "PA"
                }
            },
            "email": ""
        },
        {
            "first": "Scott",
            "middle": [],
            "last": "Wcinstein",
            "suffix": "",
            "affiliation": {},
            "email": ""
        }
    ],
    "year": "",
    "venue": null,
    "identifiers": {},
    "abstract": "",
    "pdf_parse": {
        "paper_id": "P83-1007",
        "_pdf_hash": "",
        "abstract": [],
        "body_text": [
            {
                "text": "Linguistic theories typically assign various linguistic phenomena to one of the categories, syntactic, semantic, or pragmatic, as if the phenomena in each category were relatively independent of those in the others. However, various phenomena in discourse do not seem to yield comfortably to any account that is strictly a syntactic or semantic or pragmatic one.",
                "cite_spans": [],
                "ref_spans": [],
                "eq_spans": [],
                "section": "Overview",
                "sec_num": "1."
            },
            {
                "text": "This paper focuses on particular phenomena of this sort-the use of various referring expressions such as definite noun phrases and pronouns-and examines their interaction with mechanisms used to maintain discourse coherence.",
                "cite_spans": [],
                "ref_spans": [],
                "eq_spans": [],
                "section": "Overview",
                "sec_num": "1."
            },
            {
                "text": "Even a casual survey of the literature on definite descriptions and referring expressions reveals not only defects in the individual accounts provided by theorists (from several different disciplines), but also deep confusions about the roles that syntactic, semantic, and pragmatic factors play in accounting for these phenomena. The research we have undertaken is an attempt to sort out some of these confusions and to create the basis for a theoretical framework that can account for a variety of discourse phenomena in which all three factors of language use interact. The major premise on which our research depends is that the concepts necessary for an adequate understanding of the phenomena in question are not exclusively either syntactic or semantic or pragmatic.",
                "cite_spans": [],
                "ref_spans": [],
                "eq_spans": [],
                "section": "Overview",
                "sec_num": "1."
            },
            {
                "text": "The next section of this paper defines two levels of discourse coherence and describes their roles in accounting for the use of singular definite noun phrases. To illustrate the integration of factors in explaining the uses of referring expressions, their use on one of these levels, i.e., the local one, is discussed in Sections 3 and 4. This account requires introducing the notion of the centers of a sentence in a discourse, a notion that cannot be defined in terms of factors that are exclusively syntactic or semantic or pragmatic. In Section 5, the interactions of the two levels with these factors and their effects on the uses of referring expressions in discourse are discussed.",
                "cite_spans": [],
                "ref_spans": [],
                "eq_spans": [],
                "section": "Overview",
                "sec_num": "1."
            },
            {
                "text": "A discourse comprises utterances that combine into subconstituents of the discourse, namely, units of discourse that are typically larger than a single sentence, but smaller than the complete discourse. However, the constituent structure is not determined solely by the linear sequence of utterances.",
                "cite_spans": [],
                "ref_spans": [],
                "eq_spans": [],
                "section": "Coherence",
                "sec_num": null
            },
            {
                "text": "It is common for two contiguous utterances to be members of different subconstituents of the discourse (as with breaks between phrases in the syntactic analysis of a sentence); likewise, it is common for two utterances that are not contiguous to be members of the same subconstituent.",
                "cite_spans": [],
                "ref_spans": [],
                "eq_spans": [],
                "section": "Coherence",
                "sec_num": null
            },
            {
                "text": "An individual subcoastituent of a discourse exhibits both internal coherence and coherence with the other subconstituents. That is, discourses have been shown to have two levels of coherence. Global coherence refers to the ways in which the larger segments of discourse relate to one another. It depends on such things as the function of a discourse, its subject matter, and rhetorical schema [Grosz, 1977 [Grosz, , 1981 Reichman, 1981 I. Local coherence refers to the ways in which individual sentences bind together to form larger discourse segments. It depends on such things as the syntactic structure of an utterance, ellipsis, and the use of pronominal referring expressions [Sidner, 1981 I. The two levels of discourse coherence correspond to two levels of focusing--global focusing and centering.",
                "cite_spans": [
                    {
                        "start": 393,
                        "end": 405,
                        "text": "[Grosz, 1977",
                        "ref_id": "BIBREF3"
                    },
                    {
                        "start": 406,
                        "end": 420,
                        "text": "[Grosz, , 1981",
                        "ref_id": null
                    },
                    {
                        "start": 421,
                        "end": 438,
                        "text": "Reichman, 1981 I.",
                        "ref_id": null
                    },
                    {
                        "start": 681,
                        "end": 697,
                        "text": "[Sidner, 1981 I.",
                        "ref_id": null
                    }
                ],
                "ref_spans": [],
                "eq_spans": [],
                "section": "Coherence",
                "sec_num": null
            },
            {
                "text": "Participants are said to be globally focused on a set of entitie.~ relevant to the overall discourse. These entities may either have been explicitly introduced into the discourse or be sufficiently closely related to such entities to be considered implicitly in focus [Grosz, 19811 . In contrast, centering refers to a more local focusing process, one relates to identifying the single entity that an individual utterance most centrally concerns [Sidner, 1979; Joshi and Weinstein, 1981] .",
                "cite_spans": [
                    {
                        "start": 268,
                        "end": 283,
                        "text": "[Grosz, 19811 .",
                        "ref_id": null
                    },
                    {
                        "start": 446,
                        "end": 460,
                        "text": "[Sidner, 1979;",
                        "ref_id": "BIBREF14"
                    },
                    {
                        "start": 461,
                        "end": 487,
                        "text": "Joshi and Weinstein, 1981]",
                        "ref_id": null
                    }
                ],
                "ref_spans": [],
                "eq_spans": [],
                "section": "Coherence",
                "sec_num": null
            },
            {
                "text": "IThis research was supported in part by the National Science Foundation under Grant MCS-8115105 to SRI International, and Grant MCS81-07290 to the University of Pennsylvania.",
                "cite_spans": [],
                "ref_spans": [],
                "eq_spans": [],
                "section": "Coherence",
                "sec_num": null
            },
            {
                "text": "The two levels of focusing/coherence have different effects on the processing of pronominal and nonpronominal definite noun phrases. Global coherence and focusing are major factors in the generation and interpretation of nonpronominal def'lnite referring expressions. 2 Local coherence and centering have greater effect on the processing of pronominal expressions. In Section 5 we shall describe the rules governing the use of these kinds of expressions and shall explain why additional processing by the hearer (needed for drawing additional inferences} is involved when pronominal expressions are used to refer to globally focused entities or nonpronominal expressions are used to refer to centered entities.",
                "cite_spans": [],
                "ref_spans": [],
                "eq_spans": [],
                "section": "Coherence",
                "sec_num": null
            },
            {
                "text": "Many approaches to language interpretation have ignored these differences, depending instead on powerful inference mechanisms to identify the referents of referring expressions. Although such approaches may suffice, especially for well-formed texts, they are insufficient in general. In particular, such approaches will not work for generation.",
                "cite_spans": [],
                "ref_spans": [],
                "eq_spans": [],
                "section": "Coherence",
                "sec_num": null
            },
            {
                "text": "Here the relationships among focusing, coherence, and referring expressions are essential and must be explicitly provided for. Theories-and systems based on them--will generate unacceptable uses of referring expressions if they do not take these relationships into account. 3",
                "cite_spans": [],
                "ref_spans": [],
                "eq_spans": [],
                "section": "Coherence",
                "sec_num": null
            },
            {
                "text": "In our theory, the centers of a sentence in a discourse serve to integrate that sentence into the discourse. Each sentence, S, has a single backward-looking center, Cb(S), and a set of forward-looking centers, Cf(S). Cb(S) serves to link S to the preceding discourse, while Cf(S) provides a set of entities to which the succeeding discourse may be linked. To avoid confusion, the phrase =the center\" will be used to refer only to Cb(S).",
                "cite_spans": [],
                "ref_spans": [],
                "eq_spans": [],
                "section": "Centering and Anaphora",
                "sec_num": "3."
            },
            {
                "text": "To clarify the notion of center, we will consider a number of discourses illustrating the various factors that are combined in its definition (abstractly) and in its identification in a discourse. In Section 5 we define center more precisely, show how it relates to Sidner's [1981] immediate focus and potential loci, and discuss how the linkages established by the centers of a sentence help to determine the degree of intelligibility of a discourse. We begin by showing that the center cannot be defined in syntactic terms alone. The interaction of semantics and centering is more complex and is discussed in Section 4.",
                "cite_spans": [
                    {
                        "start": 266,
                        "end": 281,
                        "text": "Sidner's [1981]",
                        "ref_id": null
                    }
                ],
                "ref_spans": [],
                "eq_spans": [],
                "section": "Centering and Anaphora",
                "sec_num": "3."
            },
            {
                "text": "The following examples, drawn from Reinhart [1982] , illustrate the point that the notion of center is not syntactically definable, 4 i.e., the syntax of a sentence S does not determine which of its NPs realizes Cb(S). (The 2They differ in other respects also. Reichman [19811 a~d Grosz [19811 discuss some of these.",
                "cite_spans": [
                    {
                        "start": 35,
                        "end": 50,
                        "text": "Reinhart [1982]",
                        "ref_id": null
                    },
                    {
                        "start": 261,
                        "end": 286,
                        "text": "Reichman [19811 a~d Grosz",
                        "ref_id": null
                    }
                ],
                "ref_spans": [],
                "eq_spans": [],
                "section": "Centering and Anaphora",
                "sec_num": "3."
            },
            {
                "text": "3Initial attempts to incorporate focusing mechanisms in generation systems are described in [Appelt, 1981 and MeKeown, 1982] . 41ntonation can obviously affect the interpretation; for the purposes of this paper, it may be regarded a~ part of a syntax. reasons for the use of this terminology axe discussed in Section 4.) Although (lb) and (2b) are identical, Cb(lb) is Max and Cb(2b) is Rosa. This can be seen in part by noticing that =He saw Rosa\" seems more natural than (lb) and =Max saw her\" than (2b) (a fact consistent with the centering rule introduced in Section 5.) The subject NP is the center in one context, the object NP in the other.",
                "cite_spans": [
                    {
                        "start": 92,
                        "end": 109,
                        "text": "[Appelt, 1981 and",
                        "ref_id": null
                    },
                    {
                        "start": 110,
                        "end": 124,
                        "text": "MeKeown, 1982]",
                        "ref_id": null
                    }
                ],
                "ref_spans": [],
                "eq_spans": [],
                "section": "Centering and Anaphora",
                "sec_num": "3."
            },
            {
                "text": "Even when the NP used to realize Cb(S) can be syntactically determined, the Cb(S) itself is not yet fully determined, for Cb(S) is typically not a linguistic entity (i.e., it is not a particular linguistic expression). Rosa, not \u00b0Rosa \u00b0 is the Cb(2b). Consider. the discourse:",
                "cite_spans": [],
                "ref_spans": [],
                "eq_spans": [],
                "section": "Centering and Anaphora",
                "sec_num": "3."
            },
            {
                "text": "(3z)",
                "cite_spans": [],
                "ref_spans": [],
                "eq_spans": [],
                "section": "Centering and Anaphora",
                "sec_num": "3."
            },
            {
                "text": "How is Rosa?",
                "cite_spans": [],
                "ref_spans": [],
                "eq_spans": [],
                "section": "Centering and Anaphora",
                "sec_num": "3."
            },
            {
                "text": "(3b) Did anyone see her yesterday?",
                "cite_spans": [],
                "ref_spans": [],
                "eq_spans": [],
                "section": "Centering and Anaphora",
                "sec_num": "3."
            },
            {
                "text": "Max saw her.",
                "cite_spans": [],
                "ref_spans": [],
                "eq_spans": [],
                "section": "Centering and Anaphora",
                "sec_num": "3."
            },
            {
                "text": "Here, Cb(3c) is Rosa, but clearly would not be in other contexts where the expression \"her\" still realized the backward-looking center of \"Max saw her.\" This is seen most simply by considering the discourse that would result if \"How is Joan?\" replaced (3a). In the discourse that resulted, Joan, not Rosa, would be the center of (3c).",
                "cite_spans": [],
                "ref_spans": [],
                "eq_spans": [],
                "section": "Centering and Anaphora",
                "sec_num": "3."
            },
            {
                "text": "The interactions of semantic and pragmatic factors with centering and their effects on referring expressions are more complex than the preceding discussion suggests. In the examples given above, the NPs that realize Cb(S) also denote it., but this is not always the case: we used the term \"realize\" in the above discussion advisedly. In this section, we consider two kinds of examples in which the center of a sentence is not simply the denotation of some noun phrase occurring in the sentence. First, we will examine several examples in which the choice of and interaction among different kinds of interpretations of definite noun phrases are affected by the local discourse context (i.e., centering}. Second, the role of pragmatic factors in some problematic cases of referential uses of definite descriptions [Donnellan 1966 ] is discussed.",
                "cite_spans": [
                    {
                        "start": 812,
                        "end": 827,
                        "text": "[Donnellan 1966",
                        "ref_id": "BIBREF2"
                    }
                ],
                "ref_spans": [],
                "eq_spans": [],
                "section": "Centering and Realization",
                "sec_num": "4."
            },
            {
                "text": "The distinction between realization and semantic denotation is necessary to treat the interaction between value-free and value-loaded interpretations [Barwise and Perry, 1982] of definite descriptions, as they occur in extended discourse. Consider, for example, the following sequence:",
                "cite_spans": [
                    {
                        "start": 150,
                        "end": 175,
                        "text": "[Barwise and Perry, 1982]",
                        "ref_id": null
                    }
                ],
                "ref_spans": [],
                "eq_spans": [],
                "section": "Realization and Value-Free and Value-Loaded Interpretations",
                "sec_num": "4.1."
            },
            {
                "text": "(4a) The vice president of the United States is also president of the Senate. (4b) Historically, he is the president's key man in negotiations with Congress. (4b') As Ambassador to China, he handled many tricky negotiations, so he is well prepared for this Job.",
                "cite_spans": [],
                "ref_spans": [],
                "eq_spans": [],
                "section": "Realization and Value-Free and Value-Loaded Interpretations",
                "sec_num": "4.1."
            },
            {
                "text": "Cb(4b) and Cb(4b') are each realized by the anaphoric element \"he. = But (4b) expresses the same thing as \"Historically, the vice president of the United States is the president's key man in negotiations with Congress\" (in which it is clear that no single individual vice president is being referred to) whereas (4b') expresses the same thing as, \"As ambassador to China, the [person who is now] vice president of the United States handled many tricky negotiations,...\"",
                "cite_spans": [],
                "ref_spans": [],
                "eq_spans": [],
                "section": "Realization and Value-Free and Value-Loaded Interpretations",
                "sec_num": "4.1."
            },
            {
                "text": "This can be accounted for by observing that \"the vice president of the United States\" contributes both its value-free interpretation and its value-loading at the world type to Cf(4a). Cb(4b) is then the value-free interpretation and Cb(4b') is the valueloading, i.e., George Bush.",
                "cite_spans": [],
                "ref_spans": [],
                "eq_spans": [],
                "section": "Realization and Value-Free and Value-Loaded Interpretations",
                "sec_num": "4.1."
            },
            {
                "text": "In this example, both value-free and value-loaded interpretations are showu to stem from the same full definite noun phrase. It is also possible for the movement of the center from a value-free interpretation (for Cb(S)) to a value-loaded interpretation (for Cb of the next sentence)-or vice versa-to be accomplished solely with pronouns. That is, although (4b)-(4b') is (at least for some readers) not a natural dialogue, similar sequences are possible.",
                "cite_spans": [],
                "ref_spans": [],
                "eq_spans": [],
                "section": "Realization and Value-Free and Value-Loaded Interpretations",
                "sec_num": "4.1."
            },
            {
                "text": "There appear to be strong constraints on the kinds of transitions that are allowed. In particular, if a given sentence forces either the value-free or value-loaded interpretation, then only that interpretation becomes possible in a subsequent sentence.",
                "cite_spans": [],
                "ref_spans": [],
                "eq_spans": [],
                "section": "Realization and Value-Free and Value-Loaded Interpretations",
                "sec_num": "4.1."
            },
            {
                "text": "However, if some sentence in a given context merely prefers one interpretation while allowing the other, then either one is possible in a subsequent sentence.",
                "cite_spans": [],
                "ref_spans": [],
                "eq_spans": [],
                "section": "Realization and Value-Free and Value-Loaded Interpretations",
                "sec_num": "4.1."
            },
            {
                "text": "For example, the sequence. in which \"he\" may be interpreted a~ either value-free (iT') or value-loaded (VL}, may be followed by either of the following two sentences:",
                "cite_spans": [],
                "ref_spans": [],
                "eq_spans": [],
                "section": "Realization and Value-Free and Value-Loaded Interpretations",
                "sec_num": "4.1."
            },
            {
                "text": "(5c) As ambassador to China. he handled many tricky negotiations.",
                "cite_spans": [],
                "ref_spans": [],
                "eq_spans": [],
                "section": "Realization and Value-Free and Value-Loaded Interpretations",
                "sec_num": "4.1."
            },
            {
                "text": "(VL) (5c') He is required to he at least 35 years old.",
                "cite_spans": [],
                "ref_spans": [],
                "eq_spans": [],
                "section": "Realization and Value-Free and Value-Loaded Interpretations",
                "sec_num": "4.1."
            },
            {
                "text": "(V'F')",
                "cite_spans": [],
                "ref_spans": [],
                "eq_spans": [],
                "section": "Realization and Value-Free and Value-Loaded Interpretations",
                "sec_num": "4.1."
            },
            {
                "text": "tlowever, if we change (Sb) to force the value-loaded interpretation, as in (5b'), then only (5c) is possible. Similarly, if {5b) is changed to force the value-free interpretation, as in {4b), then only (5c') is possible.",
                "cite_spans": [],
                "ref_spans": [],
                "eq_spans": [],
                "section": "Realization and Value-Free and Value-Loaded Interpretations",
                "sec_num": "4.1."
            },
            {
                "text": "If an intermediate sentence allows both interpretations but prefers one in a given context, then either is possible in the third sentence. A use with preference for a valueloaded interpretation followed by a use indicating the value-free interpretation is illustrated in the sequence:",
                "cite_spans": [],
                "ref_spans": [],
                "eq_spans": [],
                "section": "Realization and Value-Free and Value-Loaded Interpretations",
                "sec_num": "4.1."
            },
            {
                "text": "John thinks that the telephone \u00a3s a toy. He plays with it every day.",
                "cite_spans": [],
                "ref_spans": [],
                "eq_spans": [],
                "section": "Realization and Value-Free and Value-Loaded Interpretations",
                "sec_num": "4.1."
            },
            {
                "text": "(V~ preferred; V~ok) He doesn't realize that \u00a3t is tn \u00a3nventlon that changed the world.",
                "cite_spans": [],
                "ref_spans": [],
                "eq_spans": [],
                "section": "Realization and Value-Free and Value-Loaded Interpretations",
                "sec_num": "4.1."
            },
            {
                "text": "The preference for a value-free interpretation that is followed bv a value-loaded one is easiest to see in a dialogue situation: ",
                "cite_spans": [],
                "ref_spans": [],
                "eq_spans": [],
                "section": "(V~",
                "sec_num": null
            },
            {
                "text": "From these examples, it might appear that the concepts of value-free and value-loaded interpretation are identical to Donnellan's I19661 attributive and referential uses of noun phrases. However, there is an important difference between these two distinctions. The importance to our theory is that the referential use of definite noun phrases introduces the need to take pragmatic factors (in particular speaker intention) into account, not just seman| ic factors.",
                "cite_spans": [],
                "ref_spans": [],
                "eq_spans": [],
                "section": "Realization and Referential Use",
                "sec_num": "4.2."
            },
            {
                "text": "[1966[ describes the referential and attributive uses of definite descriptions in the following way:",
                "cite_spans": [],
                "ref_spans": [],
                "eq_spans": [],
                "section": "DonnelIan",
                "sec_num": null
            },
            {
                "text": "\"A speaker who uses a definite description attributively in an assertion states something about whoever or whatever is the so-and-so. A speaker who uses a definite description referentially in an a~sertion, on the other hand , uses the description to enable his audience to pick out whom or what he is talking about and states something about that person or thing. In the first case the definite description might be said to occur essentially, for the speaker wishes to assert something about whatever or whoever fits that description; but in the referential use the definite description is merely one tool for doing a certain job--calling attention to a person or thing--and in gefieral any other device for doing the same job, another description or a name. would do as well. In the attributive use, the attribute of being the so-and-so is all imp~,rtant, while it is not in the referential use.*",
                "cite_spans": [],
                "ref_spans": [],
                "eq_spans": [],
                "section": "DonnelIan",
                "sec_num": null
            },
            {
                "text": "The distinction Donnellan suggests can be formulated in terms of the different propositions a sentence S containing a definite description D may be used to express on differcn! occasions of use. When D is used referentially, it contributes its denotation to the proposition expressed by S; when it is used attributively, it contributes to the proposition expressed by S a semantic interpretation related to the descriptive content of D. The identity of this semantic interpretation is not something about which Donnellan is explicit. Distinct formal treatments of the semantics of definite descriptions in natural language would construe the appropriate interpretation differently. In semantic treatments based on possible worlds, the appropriate interpretation would be a (partial} function from possible worlds to objects; in the situation semantics expounded by Barwise and Perry, the appropriate interpretation is a (partial} function from resource situations 5 to objects.",
                "cite_spans": [],
                "ref_spans": [],
                "eq_spans": [],
                "section": "DonnelIan",
                "sec_num": null
            },
            {
                "text": ".As just described, the referential-attributive distinction appears to be exactly the distinction that Barwise and Perry formulate in terms of the value-loaded and valuefree interpretations of definite noun phrases. But this gloss omits an essential aspect of the referentialattributive distinction as elaborated by Donnellan. In Donnellan's view, a speaker may use a description referentially to refer to an object distinct from the semantic denotation of the description, and, moreover, to refer to an object even when the description has no semantic denotation.",
                "cite_spans": [],
                "ref_spans": [],
                "eq_spans": [],
                "section": "DonnelIan",
                "sec_num": null
            },
            {
                "text": "In one sense, this phenomenon arises within the framework of Barwise and Perry's treatment of descriptions. If we understand the semantic denotation of a description to be the unique object that satisfies the content of the description, if there is one, then Barwise and Perry would allow that there are referential uses of a description D that contribute objects other than the semantic denotation of D to the propositions expressed by uses of sentences in which D occurs. But this is only because Barwise and Perry allow that a description may be evaluated at ~ resource situation other than the complete situation in order to arrive at its denotation on a given occasion of use. Still, the denotation of the description relative to a given resource situation is the unique object in the situation that satisfies the description relative to that situation.",
                "cite_spans": [],
                "ref_spans": [],
                "eq_spans": [],
                "section": "DonnelIan",
                "sec_num": null
            },
            {
                "text": "The referential uses of descriptions that Donnellan gives examples of do not seem to arise by evaluation of descriptions at alternative resource situations, but rather through the \"referential intentions\" of the speaker in his use of the description. This aspect of referential use is a pragmatic rather than a semantic phenomenon and is best analyzed in terms of the distinction between semantic reference and speaker's reference elaborated in Kripke With (6a) and (7a), Kripke has in mind a case like the one discussed in Donnellan [1066] , in which a speaker uses a description to refer to something other than the semantic referent of that description, i.e., the unique thing that satisfies the description (if there is one). Kripke analyzes this case as an instance of the general phenomenon of a clash of intentions in language use. In the case at hand, the speaker has a general intention to use the description to refer to its semantic referent; his specific intention, distinct from his general semantic intention, is to use it to refer to a particular individual. He incorrectly believes that these two intentions coincide and this gives rise to a use of the referring expression \"her husband\" in which the speaker's reference and the semantic reference are distinct. \"8 (The speaker's referent is presumably the woman's ]over).",
                "cite_spans": [
                    {
                        "start": 524,
                        "end": 540,
                        "text": "Donnellan [1066]",
                        "ref_id": null
                    }
                ],
                "ref_spans": [],
                "eq_spans": [],
                "section": "DonnelIan",
                "sec_num": null
            },
            {
                "text": "From our point of view, the importance of the case resides in its showing that Cf(S) may include more than one entity, that is realized by a single NP in S. In this case, \"her husband\" contributes both the husband and the lover to Cf{6a} and Cf(Ta). This can be seen by observing that both discourses seem equally appropriate and that the backward-looking centers of (6b) and /7b) are the husband and the lover, respectively, realized by their anaphoric elements. Hence, the forward-looking centers of a sentence may be related not semantically but pragmatically to the NPs that realize them. Hence, the importance of the referential/attributive distinction from our point of view is that it leads to cases in which the centers of a sentence may be pragmatically rather than semantically related to the noun phrases that realize them.",
                "cite_spans": [],
                "ref_spans": [],
                "eq_spans": [],
                "section": "DonnelIan",
                "sec_num": null
            },
            {
                "text": "In the foregoing sections we have discussed a number of examples to illustrate two essential points. First, the noun phrase that realizes the backward-looking center of an utterance in a discourse cannot be determined from the syntax of the utterance alone. Second, the relation N realizes c between noun phrases N and centers c is neither solely a semantic nor solely a pragmatic relation. This discussion has proceeded at a rather intuitive level, without explicit elaboration of the framework we regard as appropriate for dealing with centering and its role in explaining disco,trse phenomena. Before going on to describe constraints on the realization relation that 5Roughly, *any situation on which the speaker can focus attention \u00b0 is a potential candidate for a resource situation with respect to which the speaker may value load his uses of definite descriptions. Such resource situations must contain a unique object which satisfies the description.",
                "cite_spans": [],
                "ref_spans": [],
                "eq_spans": [],
                "section": "Constraints",
                "sec_num": null
            },
            {
                "text": "6There are, of course, several alternative explanations; e.g., the speaker may believe that the description is more likely than an accurate one to be interpreted correctly by the hearer. Ferreting out exactly what the case is in a given situation requires accounts of mutual belief and the like. A discussion of these issues is beyond the scope of this paper. explain certain phenomena in discourse, we should be somewhat more explicit about the notions of center and realization.",
                "cite_spans": [],
                "ref_spans": [],
                "eq_spans": [],
                "section": "Constraints",
                "sec_num": null
            },
            {
                "text": "We have said that each utterance S in a discourse has associated with it a backward-looking center, Cb(S), and a set of forward-looking centers, Cf(S). What manner of objects are these centers? They are the sort of objects that can serve as the semantic interpretations of singular noun phrases. 7 That is, either they are objects in the world (e.g., planets, people, numbers} or they are functions from possible worlds (situations, etc.} to objects in the world that can be used to interpret definite descriptions. That is, whatever serves to interpret a definite noun phrase can be a center.",
                "cite_spans": [],
                "ref_spans": [],
                "eq_spans": [],
                "section": "Constraints",
                "sec_num": null
            },
            {
                "text": "For the sake of concreteness in many of the examples in the preceding discussion, we have relied on the situation semantics of Barwise and Perry. The theory we are developing does not depend on this particular semantical treatment of definite noun phrases, but it does require several of the distinctions that treatment provides. In particular, our theory requires a semantical treatment that accommodates the distinction between interpretations of definite noun phrases that contribute their content to the propositions expressed by sentences in which they occur and interpretations that contribute only their denotation-in other words, the distinction between value-free and value-loaded interpretations. As noted, a distinction of this sort can be effected within the framework of \"possible-worlds\" approaches to the semantics of natural language. In addition, we see the need for interpretations of definite noun phrases to be dependent on their discourse context. Once again, this is a feature of interpretations that is accommodated in the relational approach to semantics advocated by Barwise and Perry, but it might be accommodated within other approaches as well. 8",
                "cite_spans": [],
                "ref_spans": [],
                "eq_spans": [],
                "section": "Constraints",
                "sec_num": null
            },
            {
                "text": "Given that Cb(S), the center of sentence S in a discourse, is the interpretation of a definite noun phrase, how does it become related to S? In a typical example, S will contain a full definite noun phrase or pronoun that realizes the center. The realization relation is neither semantic nor pragmatic. For example, N realizes c may hold in cages where N is a definite description and c is its denotation, its value-free interpretation, or an object related to it by a \"speaker's reference.\" More importantly, when N is a pronoun, the principles that govern which c are such that N realizes c derive from neither semantics nor pragmatics exclusively. They are principles that must be elicited from the study of discourse itself. A tentative formulation of some such principles is given below.",
                "cite_spans": [],
                "ref_spans": [],
                "eq_spans": [],
                "section": "Constraints",
                "sec_num": null
            },
            {
                "text": "Though it is typical that, when c is a center of S, S contains an N such that N realizes c, it is by no means necessary. In particular, for sentences containing noun 7In a fuller treatment of our theory we will consider centers that are realized by constituents in other syntactic categories.",
                "cite_spans": [],
                "ref_spans": [],
                "eq_spans": [],
                "section": "Constraints",
                "sec_num": null
            },
            {
                "text": "81srael [1983] discusses some of these issues and compares several properties of situation semantics with Montague semantics.",
                "cite_spans": [
                    {
                        "start": 8,
                        "end": 14,
                        "text": "[1983]",
                        "ref_id": null
                    }
                ],
                "ref_spans": [],
                "eq_spans": [],
                "section": "Constraints",
                "sec_num": null
            },
            {
                "text": "phrases that express functional relations (e.g., \"the door,\" \u2022 the owner'} whose arguments are not exhibited explicitly (e.g., a house is the current center, but so far neither its door nor its owner has been mentioned), 9 it is sometimes the case that such an argument can be the backward-looking center of the sentence. We are currently studying such cases and expect to integrate that study into our theory of discourse phenomena.",
                "cite_spans": [],
                "ref_spans": [],
                "eq_spans": [],
                "section": "Constraints",
                "sec_num": null
            },
            {
                "text": "The basic rule that constrains the realization of the backward-looking center of an utterance is a constraint on the speaker, namely:",
                "cite_spans": [],
                "ref_spans": [],
                "eq_spans": [],
                "section": "Constraints",
                "sec_num": null
            },
            {
                "text": "[f the Cb of the current utterance is the same as the Cb of the previous utterance, a pronoun should be used.",
                "cite_spans": [],
                "ref_spans": [],
                "eq_spans": [],
                "section": "Constraints",
                "sec_num": null
            },
            {
                "text": "There are two things to note about this rule. First, it does not preclude using pronouns for other entities as long as one is used for the center. Second, it is not a hard rule, but rather a principle, like a Gricean maxim, that can be violated. However, such violations lead at best to conditions in which the hearer is forced to draw additional inferences.",
                "cite_spans": [],
                "ref_spans": [],
                "eq_spans": [],
                "section": "Constraints",
                "sec_num": null
            },
            {
                "text": "As a simple example, consider the following sequence, assuming at the outset that John is the center of the discourse: (8b) is unacceptable, unless it is possible to consider the introduction of a second person named \"John.\" However, intervening sentences that provide for a shift in center from John to Mike (e.g., \"He was studying for his driver's test') suffice to make (8b) completely acceptable.",
                "cite_spans": [],
                "ref_spans": [],
                "eq_spans": [],
                "section": "Constraints",
                "sec_num": null
            },
            {
                "text": "Sidner's discourse focus corresponds roughly to Cb(S), while her potential foci correspond approximately to Cf(S). However, she also introduces an actor focus to handle multiple pronouns in a single utterance. The basic centering rule not only aLlows us to handle the same examples more simply, but also appears to avoid one of the complications in Sidner's account. Example D4 from Sidner [1081} illustrates this problem:",
                "cite_spans": [],
                "ref_spans": [],
                "eq_spans": [],
                "section": "Constraints",
                "sec_num": null
            },
            {
                "text": "(9-1)I haven't seen Jeff for several days, (9-2)Carl thinks he's studying for his exams. (9-3)But I think he Tent bo the Cape with Llnda.",
                "cite_spans": [],
                "ref_spans": [],
                "eq_spans": [],
                "section": "Constraints",
                "sec_num": null
            },
            {
                "text": "On Sidner's account, Carl is the actor focus after (0-2) and Jeff is the discourse focus (Cb(9-2)). Because the actor focus is preferred as the referrent of pronominal expressions, Carl is the leading candidate for the entity referred to by he in {9-3}. It is difficult to rule this case out without invoking fairly special rules. On our account, Jeff is Cb(0-2) and there is no problem. The addition of actor focus was made to handle multiple pronouns--for example, if (9-3) were replaced by He thinks he studies too much.",
                "cite_spans": [],
                "ref_spans": [],
                "eq_spans": [],
                "section": "Constraints",
                "sec_num": null
            },
            {
                "text": "The center rule allows such uses, without introducing a 9Grosz [1977] refers to this a~ \"implicit focusing'; other examples are presented in Joshi and Weinstein [1981] second kind of focus (or center), by permitting entities other than Cb(S) to be pronominalized as long as Cb(S) is.l\u00b0 Two aspects of centering affect the kinds of inferences a hearer must draw in interpreting a definite description. First, the shifting of center from one entity to another requires recognition of this change.",
                "cite_spans": [
                    {
                        "start": 63,
                        "end": 69,
                        "text": "[1977]",
                        "ref_id": null
                    },
                    {
                        "start": 141,
                        "end": 167,
                        "text": "Joshi and Weinstein [1981]",
                        "ref_id": null
                    }
                ],
                "ref_spans": [],
                "eq_spans": [],
                "section": "Constraints",
                "sec_num": null
            },
            {
                "text": "Most often such changes are affected by the use of full definite noun phrases, but in some instances a pronoun may be used. For example, Grosz [1977] presents several examples of pronouns being used to refer to objects mentioned many utterances back.",
                "cite_spans": [
                    {
                        "start": 137,
                        "end": 149,
                        "text": "Grosz [1977]",
                        "ref_id": "BIBREF3"
                    }
                ],
                "ref_spans": [],
                "eq_spans": [],
                "section": "Constraints",
                "sec_num": null
            },
            {
                "text": "Second, the hearer must process (interpret) the particular linguistic expression that realizes the center.",
                "cite_spans": [],
                "ref_spans": [],
                "eq_spans": [],
                "section": "Constraints",
                "sec_num": null
            },
            {
                "text": "Most previous attempts to account for the interaction of different kinds of referring expressions with centering and focusing (or \"topic') have conflated these two. For example, Joshi and Weinstein [1981] present a preliminary report on their research regarding the connection between the computational complexity of the inferences required to process a discourse and the coherence of that discourse as assessed by measures that invoke the centering phenomenon. However, several of the examples combine changes of expression and shifts in centering.",
                "cite_spans": [
                    {
                        "start": 178,
                        "end": 204,
                        "text": "Joshi and Weinstein [1981]",
                        "ref_id": null
                    }
                ],
                "ref_spans": [],
                "eq_spans": [],
                "section": "Constraints",
                "sec_num": null
            },
            {
                "text": "Violations of the basic centering rule require the hearer to draw two different kinds of inferences. The kind required depends on whether a full definite noun phrase is used to express the center or whether a pronoun is used for a noncentered entity. We will consider each case separately.",
                "cite_spans": [],
                "ref_spans": [],
                "eq_spans": [],
                "section": "Constraints",
                "sec_num": null
            },
            {
                "text": "Several different functions may be served by the use of a full definite noun phrase to realize the currently centered entity. For instance, the full noun phrase may include some new and unshared information about the entity. In such cases, additional inferences arise from the need to determine that the center has not shifted and that the properties expressed hold for the centered entity. For example, in the following sequences (I0) I toole i 7 clog to the vet the other day.",
                "cite_spans": [],
                "ref_spans": [],
                "eq_spans": [],
                "section": "Constraints",
                "sec_num": null
            },
            {
                "text": "The mangy old beast... the full definite noun phrases that are in boldface do more than merely refer.",
                "cite_spans": [],
                "ref_spans": [],
                "eq_spans": [],
                "section": "Constraints",
                "sec_num": null
            },
            {
                "text": "When the current center is not pronominalized (it may not be present in the sentence), the use of a pronoun to express an entity other than the current center, is strongly constrained. The particular cases that have been identified involve instances in which attention is being shifted back to a previously centered entity (e.g., Grosz, 1977; Reichman, 1978) or to one element of a set that is currently centered. In such cases, additional inferences 10Obviously, if Cb(S) is not expressed'in the next sentence then this issue does not arise. are required to determine that the pronoun does not refer to the current center, as well as to identify the context back to which attention is shifting. These shifts, though indicated by linguistic expressions typically used for centering (pronouns), correspond to a shift in global focus.",
                "cite_spans": [
                    {
                        "start": 330,
                        "end": 342,
                        "text": "Grosz, 1977;",
                        "ref_id": "BIBREF3"
                    },
                    {
                        "start": 343,
                        "end": 358,
                        "text": "Reichman, 1978)",
                        "ref_id": "BIBREF11"
                    }
                ],
                "ref_spans": [],
                "eq_spans": [],
                "section": "Constraints",
                "sec_num": null
            },
            {
                "text": "The main purpose of the paper was to sort out the confusion about the roles of syntactic, semantic, and pragmatic factors in the interpretation and generation of definite noun phrases in discourse. Specific mechanisms that account for the interactions among these factors were presented. Discourses were shown to be coherent at two different levels, i.e., with referring expressions used to identify entities that are centered locally and those focused upon more globally. The differences between references at the global and local levels were discussed, and the interaction of the syntactic role of a given noun phrase and its semantic interpretation with centering was described.",
                "cite_spans": [],
                "ref_spans": [],
                "eq_spans": [],
                "section": "Summary",
                "sec_num": "8."
            }
        ],
        "back_matter": [],
        "bib_entries": {
            "BIBREF0": {
                "ref_id": "b0",
                "title": "Planning Natural-Language Utterances",
                "authors": [
                    {
                        "first": "D",
                        "middle": [
                            "E"
                        ],
                        "last": "Appelt",
                        "suffix": ""
                    }
                ],
                "year": 1982,
                "venue": "\u00b0 Proc. of the National Conference on Artificial Intelligence",
                "volume": "",
                "issue": "",
                "pages": "",
                "other_ids": {},
                "num": null,
                "urls": [],
                "raw_text": "Appelt, D.E., \"Planning Natural-Language Utterances, \u00b0 Proc. of the National Conference on Artificial Intelligence, Pittsburgh, Pennsylvania (August 1982).",
                "links": null
            },
            "BIBREF2": {
                "ref_id": "b2",
                "title": "Reference and Definite Description",
                "authors": [
                    {
                        "first": "K",
                        "middle": [],
                        "last": "Donnellan",
                        "suffix": ""
                    }
                ],
                "year": 1966,
                "venue": "Philosophical Review",
                "volume": "60",
                "issue": "",
                "pages": "281--304",
                "other_ids": {},
                "num": null,
                "urls": [],
                "raw_text": "Donnellan, K., \"Reference and Definite Description,\" Philosophical Review, Vol. 60, pp. 281-304 (1966).",
                "links": null
            },
            "BIBREF3": {
                "ref_id": "b3",
                "title": "The Representation and Use of Focus in Dialogue Understanding",
                "authors": [
                    {
                        "first": "B",
                        "middle": [
                            "J"
                        ],
                        "last": "Grosz",
                        "suffix": ""
                    }
                ],
                "year": 1977,
                "venue": "Artificial Intelligence Center, SRI International",
                "volume": "",
                "issue": "151",
                "pages": "",
                "other_ids": {},
                "num": null,
                "urls": [],
                "raw_text": "Grosz, B.J., \"The Representation and Use of Focus in Dialogue Understanding,\" Ph.D. Thesis, University of California, Berkeley. Also, Technical Note No. 151, Artificial Intelligence Center, SRI International. (1977).",
                "links": null
            },
            "BIBREF4": {
                "ref_id": "b4",
                "title": "Focusing and Description Language Dialogues",
                "authors": [
                    {
                        "first": "B",
                        "middle": [
                            "J"
                        ],
                        "last": "Grosz",
                        "suffix": ""
                    }
                ],
                "year": null,
                "venue": "",
                "volume": "",
                "issue": "",
                "pages": "",
                "other_ids": {},
                "num": null,
                "urls": [],
                "raw_text": "Grosz, B.J., \"Focusing and Description Language Dialogues,\" Elements of",
                "links": null
            },
            "BIBREF6": {
                "ref_id": "b6",
                "title": "A Prolegomenon to Situation Semantics",
                "authors": [
                    {
                        "first": "D",
                        "middle": [
                            "J"
                        ],
                        "last": "Israel",
                        "suffix": ""
                    }
                ],
                "year": null,
                "venue": "",
                "volume": "",
                "issue": "",
                "pages": "",
                "other_ids": {},
                "num": null,
                "urls": [],
                "raw_text": "Israel, D.J., \"A Prolegomenon to Situation Semantics,\"",
                "links": null
            },
            "BIBREF7": {
                "ref_id": "b7",
                "title": "Proc. of the 21st Annual Meeting of the Assoc. for Computational Linguistics",
                "authors": [],
                "year": 1983,
                "venue": "",
                "volume": "",
                "issue": "",
                "pages": "",
                "other_ids": {},
                "num": null,
                "urls": [],
                "raw_text": "Proc. of the 21st Annual Meeting of the Assoc. for Computational Linguistics, Cambridge, Mass. (June 15-17, 1983).",
                "links": null
            },
            "BIBREF8": {
                "ref_id": "b8",
                "title": "Control of Inference: Role of Some Aspects of Discourse Structure-Centering",
                "authors": [
                    {
                        "first": "A",
                        "middle": [],
                        "last": "Joshi",
                        "suffix": ""
                    },
                    {
                        "first": "S",
                        "middle": [],
                        "last": "Weinstein",
                        "suffix": ""
                    }
                ],
                "year": null,
                "venue": "Proc. bzternational Joint Conference on Artificial Intelligence",
                "volume": "",
                "issue": "",
                "pages": "385--387",
                "other_ids": {},
                "num": null,
                "urls": [],
                "raw_text": "Joshi, A. and S. Weinstein, \"Control of Inference: Role of Some Aspects of Discourse Structure-Centering,\" Proc. bzternational Joint Conference on Artificial Intelligence, Vancouver, B.C. pp. 385-387 {August 24-28, I08t).",
                "links": null
            },
            "BIBREF9": {
                "ref_id": "b9",
                "title": "Contemporary Pespectives in the Philosophy of Language",
                "authors": [
                    {
                        "first": "S",
                        "middle": [],
                        "last": "Kripke",
                        "suffix": ""
                    }
                ],
                "year": 1977,
                "venue": "",
                "volume": "",
                "issue": "",
                "pages": "6--27",
                "other_ids": {},
                "num": null,
                "urls": [],
                "raw_text": "Kripke, S., \"Speaker's Reference and Semantic Reference,\" Contemporary Pespectives in the Philosophy of Language, University of Minnesota Press, Minneapolis, Minnesota, pp. 6-27, (1977).",
                "links": null
            },
            "BIBREF10": {
                "ref_id": "b10",
                "title": "The TEXT System for Natural Language Generation: An Overview",
                "authors": [
                    {
                        "first": "K",
                        "middle": [
                            "R"
                        ],
                        "last": "Mckeown",
                        "suffix": ""
                    }
                ],
                "year": 1982,
                "venue": "Proc. of the 20th .4nnual Aieeting of the Assoc. for Computational Linguistics",
                "volume": "",
                "issue": "",
                "pages": "16--18",
                "other_ids": {},
                "num": null,
                "urls": [],
                "raw_text": "McKeown, K.R., \"The TEXT System for Natural Language Generation: An Overview,\" Proc. of the 20th .4nnual Aieeting of the Assoc. for Computational Linguistics, 16-18 June 1982, Toronto, Ontario, Canada (June 1982}.",
                "links": null
            },
            "BIBREF11": {
                "ref_id": "b11",
                "title": "Conversational Coherency",
                "authors": [
                    {
                        "first": "R",
                        "middle": [],
                        "last": "Reichman",
                        "suffix": ""
                    }
                ],
                "year": 1978,
                "venue": "Cognitive Science",
                "volume": "2",
                "issue": "4",
                "pages": "283--327",
                "other_ids": {},
                "num": null,
                "urls": [],
                "raw_text": "Reichman, R. \"Conversational Coherency,\" Cognitive Science Vol. 2, No. 4, pp. 283-327, (1978}.",
                "links": null
            },
            "BIBREF12": {
                "ref_id": "b12",
                "title": "Plain Speaking: A Theory and Grammar of Spontaneous Discourse",
                "authors": [
                    {
                        "first": "R",
                        "middle": [],
                        "last": "Reichman",
                        "suffix": ""
                    }
                ],
                "year": 1981,
                "venue": "",
                "volume": "",
                "issue": "",
                "pages": "",
                "other_ids": {},
                "num": null,
                "urls": [],
                "raw_text": "Reichman, R. \"Plain Speaking: A Theory and Grammar of Spontaneous Discourse,\" Technical Report No. 4681, Bolt Beranek and Newman, Cambridge, Mass. (June 1981).",
                "links": null
            },
            "BIBREF13": {
                "ref_id": "b13",
                "title": "Prag'maties and Linguistics, An Analysis of Sentence Topics",
                "authors": [
                    {
                        "first": "T",
                        "middle": [],
                        "last": "Reinhart",
                        "suffix": ""
                    }
                ],
                "year": 1978,
                "venue": "Indiana University Linguistics Club",
                "volume": "",
                "issue": "",
                "pages": "",
                "other_ids": {},
                "num": null,
                "urls": [],
                "raw_text": "Reinhart, T., \"Prag'maties and Linguistics, An Analysis of Sentence Topics,\" Indiana University Linguistics Club, Bloomington, Indiana (1978).",
                "links": null
            },
            "BIBREF14": {
                "ref_id": "b14",
                "title": "Toward a Computational Theory of Definite Anaphora Comprehension in English",
                "authors": [
                    {
                        "first": "C",
                        "middle": [
                            "L"
                        ],
                        "last": "Sidner",
                        "suffix": ""
                    }
                ],
                "year": 1979,
                "venue": "",
                "volume": "",
                "issue": "",
                "pages": "",
                "other_ids": {},
                "num": null,
                "urls": [],
                "raw_text": "Sidner, C.L., Toward a Computational Theory of Definite Anaphora Comprehension in English, MIT Technical Report AI-TR-537, (1979).",
                "links": null
            },
            "BIBREF15": {
                "ref_id": "b15",
                "title": "Focusing for Interpretation of Pronouns",
                "authors": [
                    {
                        "first": "C",
                        "middle": [],
                        "last": "Sidner",
                        "suffix": ""
                    }
                ],
                "year": null,
                "venue": "",
                "volume": "",
                "issue": "",
                "pages": "",
                "other_ids": {},
                "num": null,
                "urls": [],
                "raw_text": "Sidner, C., \"Focusing for Interpretation of Pronouns,\"",
                "links": null
            }
        },
        "ref_entries": {
            "FIGREF1": {
                "num": null,
                "text": "Sa) The vice president of the United States is also president of the Senate. (Sb) He's the president's key a~ in ne~otiatione with Congress.",
                "type_str": "figure",
                "uris": null
            },
            "FIGREF2": {
                "num": null,
                "text": "$b') Right non he is the president's key man \u00a3n negotiations sith Congress.",
                "type_str": "figure",
                "uris": null
            },
            "FIGREF4": {
                "num": null,
                "text": "is kind to her but be isn't her husband.",
                "type_str": "figure",
                "uris": null
            },
            "FIGREF5": {
                "num": null,
                "text": "Sa) He called up Mike yesterday. (he=John) (Sb) He ,as annoyed by John's call.",
                "type_str": "figure",
                "uris": null
            },
            "FIGREF6": {
                "num": null,
                "text": "11) I'm reading The French Lieutenant's Woman. The book, which In Fowles best ....",
                "type_str": "figure",
                "uris": null
            }
        }
    }
}