File size: 82,891 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
1131
1132
1133
1134
1135
1136
1137
1138
1139
1140
1141
1142
1143
1144
1145
1146
1147
1148
1149
1150
1151
1152
1153
1154
1155
1156
1157
1158
1159
1160
1161
1162
1163
1164
1165
1166
1167
1168
1169
1170
1171
1172
1173
1174
1175
1176
1177
1178
1179
1180
1181
1182
1183
1184
1185
1186
1187
1188
1189
1190
1191
1192
1193
1194
1195
1196
1197
1198
1199
1200
1201
1202
1203
1204
1205
1206
1207
1208
1209
1210
1211
1212
1213
1214
1215
1216
1217
1218
1219
1220
1221
1222
1223
1224
1225
1226
1227
1228
1229
1230
1231
1232
1233
1234
1235
1236
1237
1238
1239
1240
1241
1242
1243
1244
1245
1246
1247
1248
1249
1250
1251
1252
1253
1254
1255
1256
1257
1258
1259
1260
1261
1262
1263
1264
1265
1266
1267
1268
1269
1270
1271
1272
1273
1274
1275
1276
1277
1278
1279
1280
1281
1282
1283
1284
1285
1286
1287
1288
1289
1290
1291
1292
1293
1294
1295
1296
1297
1298
1299
1300
1301
1302
1303
1304
1305
1306
1307
1308
1309
1310
1311
1312
1313
1314
1315
1316
1317
1318
1319
1320
1321
1322
1323
1324
1325
1326
1327
1328
1329
1330
1331
1332
1333
1334
1335
1336
1337
1338
1339
1340
1341
1342
1343
1344
1345
1346
1347
1348
1349
1350
1351
1352
1353
1354
1355
1356
1357
1358
1359
1360
1361
1362
1363
1364
1365
1366
1367
1368
1369
1370
1371
1372
1373
1374
1375
1376
1377
1378
1379
1380
1381
1382
1383
1384
1385
1386
1387
1388
1389
1390
1391
1392
1393
1394
1395
1396
1397
1398
1399
1400
1401
1402
1403
1404
1405
1406
1407
1408
1409
1410
1411
1412
1413
1414
1415
1416
1417
1418
1419
1420
1421
1422
1423
1424
1425
1426
1427
1428
1429
1430
1431
1432
1433
1434
1435
1436
1437
1438
1439
1440
1441
1442
1443
1444
1445
1446
1447
1448
1449
1450
1451
1452
1453
1454
1455
1456
1457
1458
1459
1460
1461
1462
1463
1464
1465
1466
1467
1468
1469
1470
1471
1472
1473
1474
1475
1476
1477
1478
1479
1480
1481
1482
1483
1484
1485
1486
1487
1488
{
    "paper_id": "I11-1039",
    "header": {
        "generated_with": "S2ORC 1.0.0",
        "date_generated": "2023-01-19T07:30:45.626131Z"
    },
    "title": "Predicting Opinion Dependency Relations for Opinion Analysis",
    "authors": [
        {
            "first": "Lun-Wei",
            "middle": [],
            "last": "Ku",
            "suffix": "",
            "affiliation": {
                "laboratory": "",
                "institution": "National Yunlin University of Science and Technology Douliou",
                "location": {
                    "postCode": "64002",
                    "settlement": "Yunlin",
                    "country": "Taiwan"
                }
            },
            "email": "lwku@yuntech.edu.tw"
        },
        {
            "first": "Ting-Hao",
            "middle": [
                "Kenneth"
            ],
            "last": "Huang",
            "suffix": "",
            "affiliation": {
                "laboratory": "",
                "institution": "National Taiwan University",
                "location": {
                    "addrLine": "No.1, Sec.4, Roosevelt Rd",
                    "settlement": "Taipei",
                    "country": "Taiwan"
                }
            },
            "email": "tinghaoh@andrew.cmu.edu"
        },
        {
            "first": "Hsin-Hsi",
            "middle": [],
            "last": "Chen",
            "suffix": "",
            "affiliation": {
                "laboratory": "",
                "institution": "National Taiwan University",
                "location": {
                    "addrLine": "No.1, Sec.4, Roosevelt Rd",
                    "settlement": "Taipei",
                    "country": "Taiwan"
                }
            },
            "email": "hhchen@ntu.edu.tw"
        }
    ],
    "year": "",
    "venue": null,
    "identifiers": {},
    "abstract": "Syntactic structures have been good features for opinion analysis, but it is not easy to use them. To find these features by supervised learning methods, correct syntactic labels are indispensible. Two possible sources to acquire syntactic structures are parsing trees and dependency trees. For the annotation processing, parsing trees are more readable for annotators, while dependency trees are easier to use by programs. To use syntactic structures as features, this paper tried to annotate on human friendly materials and transform these annotations to the corresponding machine friendly materials. We annotated the gold answers of opinion syntactic structures on the parsing tree from Chinese Treebank, and then proposed methods to find their corresponding dependency relations on the dependency trees generated from the same sentence. With these relations, we could train a model to annotate opinion dependency relations automatically to provide an opinion dependency parser, which is language independent if language resources are incorporated. Experiment results show that the annotated syntactic structures and their corresponding dependency relations improve at least 8% of the performance of opinion analysis.",
    "pdf_parse": {
        "paper_id": "I11-1039",
        "_pdf_hash": "",
        "abstract": [
            {
                "text": "Syntactic structures have been good features for opinion analysis, but it is not easy to use them. To find these features by supervised learning methods, correct syntactic labels are indispensible. Two possible sources to acquire syntactic structures are parsing trees and dependency trees. For the annotation processing, parsing trees are more readable for annotators, while dependency trees are easier to use by programs. To use syntactic structures as features, this paper tried to annotate on human friendly materials and transform these annotations to the corresponding machine friendly materials. We annotated the gold answers of opinion syntactic structures on the parsing tree from Chinese Treebank, and then proposed methods to find their corresponding dependency relations on the dependency trees generated from the same sentence. With these relations, we could train a model to annotate opinion dependency relations automatically to provide an opinion dependency parser, which is language independent if language resources are incorporated. Experiment results show that the annotated syntactic structures and their corresponding dependency relations improve at least 8% of the performance of opinion analysis.",
                "cite_spans": [],
                "ref_spans": [],
                "eq_spans": [],
                "section": "Abstract",
                "sec_num": null
            }
        ],
        "body_text": [
            {
                "text": "Opinion analysis has drawn much attention in research communities of machine learning and natural language processing. In the early stages, words in documents were used as the main features (Pang et al., 2002) . Some opinion dictionaries were created for this demand . However, researchers soon realized that word features were not sufficient for acquiring good performances, so they started to include syntactic structures and semantic in-formation (Qiu et al., 2008) . Their researches showed that linguistic knowledge is helpful in determining opinions.",
                "cite_spans": [
                    {
                        "start": 190,
                        "end": 209,
                        "text": "(Pang et al., 2002)",
                        "ref_id": "BIBREF12"
                    },
                    {
                        "start": 450,
                        "end": 468,
                        "text": "(Qiu et al., 2008)",
                        "ref_id": "BIBREF13"
                    }
                ],
                "ref_spans": [],
                "eq_spans": [],
                "section": "Introduction",
                "sec_num": "1"
            },
            {
                "text": "For various applications related to opinions, syntactic structures have become powerful tools for extracting useful clues. To find opinions in product reviews, modification relations were used to identify the product and their features (Lu et al., 2009) , e.g., a good price (feature) of this camera (product). To find opinion holders and targets, templates and linguistic rules were adopted (Breck et al., 2007) . To find more opinion words, dependency relations were utilized (Qiu et al., 2011) . Even when applying the basic negation rule that flips opinion polarity over, we need to find its modified word first by syntactic clues. However, we will show that syntactic relations do not directly suggest opinions.",
                "cite_spans": [
                    {
                        "start": 236,
                        "end": 253,
                        "text": "(Lu et al., 2009)",
                        "ref_id": "BIBREF10"
                    },
                    {
                        "start": 392,
                        "end": 412,
                        "text": "(Breck et al., 2007)",
                        "ref_id": "BIBREF2"
                    },
                    {
                        "start": 478,
                        "end": 496,
                        "text": "(Qiu et al., 2011)",
                        "ref_id": "BIBREF14"
                    }
                ],
                "ref_spans": [],
                "eq_spans": [],
                "section": "Introduction",
                "sec_num": "1"
            },
            {
                "text": "Syntactic relations are obtained usually from all kinds of syntax trees. Parsing trees (phrase structured) and dependency trees (grammatical) are the most commonly seen ones. Parsing trees are in-order trees which keep the order of words in sentences, so they are more readable for people. Instead, nodes in dependency trees are displayed by the head-modifier relations, in which the sentence sequence probably is not remained. People could find the opinion passages if they can understand the whole sentence, i.e. from parsing trees. However, when the linguistic background is needed, it could be difficult for most people to reconstruct the whole sentence from the dependency trees in order to find the opinion passage. Therefore, if we want to find annotators to build a corpus which could be used to train an opinion relation recognizer, parsing trees are the better materials compared to dependency trees. However, compared to relations between words, complicated tree structures are more challenge to be utilized by algorithms (Doan et al., 2008) . This paper focuses on extracting opinionated dependency relations from relations generated by the Stanford parser. We design an annotation mechanism on the syntactic structures on the sentence from Chinese Treebank to create an annotation environment with a lower entry barrier so that sufficient annotations can be labeled. Then these annotations are aligned to the relations in the corresponding dependency trees generated by the same parser from the same sentence as the gold standard for training the automatic annotator of the opinion dependency relations. We conduct experiments on the annotated opinion syntactic structures in parsing trees, and on the opinion dependency relations corresponding to them. The proposed process demonstrates a feasible direction toward the development of an opinion dependency parser.",
                "cite_spans": [
                    {
                        "start": 1033,
                        "end": 1052,
                        "text": "(Doan et al., 2008)",
                        "ref_id": "BIBREF4"
                    }
                ],
                "ref_spans": [],
                "eq_spans": [],
                "section": "Introduction",
                "sec_num": "1"
            },
            {
                "text": "Given a set of non-collapsed dependencies parsed from a specific sentence by the Stanford dependency parser (de Marneffe and Manning, 2008; Chang et al., 2009) , each associated with a dependency relation between two words in this sentence, our goal is to identify which of them are with sentiment, i.e., those which reveal a part of opinions or the aroused emotions. For example, in the sentence \"\u6d3b\u52a8 \u53d6\u5f97 \u4e86 \u5706\u6ee1 \u6210\u529f (Activities scored le perfect success)\", the Stanford dependency parser gives three relations: nmod(\u6210\u529f <success>, \u5706 \u6ee1 <perfect>), nsubj( \u53d6 \u5f97 <scored>, \u6d3b \u52a8 <activities>), dobj(\u53d6\u5f97 <scored>, \u6210\u529f<success>), and asp(\u53d6\u5f97 <scored>, \u4e86<le>). The goal is to identify the former three may bear sentiment or opinions. The corresponding dependency tree is shown in Figure 1 . From Figure 1 we can also see that it is not easy to read the original sentence without the linguistic background. Formally, the collection of the noncollapsed dependency relations of a sentence S, generated by the Stanford dependency parser, is denoted by Rdep(S) = {r 1 , r 2 , \u2026}, where each ) (S Rdep r i \uf0ce is associate with an opinion judgment of op(r).",
                "cite_spans": [
                    {
                        "start": 108,
                        "end": 139,
                        "text": "(de Marneffe and Manning, 2008;",
                        "ref_id": "BIBREF11"
                    },
                    {
                        "start": 140,
                        "end": 159,
                        "text": "Chang et al., 2009)",
                        "ref_id": "BIBREF3"
                    }
                ],
                "ref_spans": [
                    {
                        "start": 762,
                        "end": 770,
                        "text": "Figure 1",
                        "ref_id": "FIGREF0"
                    },
                    {
                        "start": 778,
                        "end": 786,
                        "text": "Figure 1",
                        "ref_id": "FIGREF0"
                    }
                ],
                "eq_spans": [],
                "section": "Problem Definition",
                "sec_num": "2"
            },
            {
                "text": "Definition: Dependency Relation The dependency relation r, generated by the Stanford parser, is composed of the type of relation rel, the head word w h and the modifier word w m in the form of rel(w h , w m ). w h and w m are two individual words in S. For example, in one relation in Figure 1 , r = nmod(\u6210\u529f <success>, \u5706\u6ee1 <perfect>), where rel = nmod, w h =\u6210\u529f <suc-cess>, and w m =\u5706\u6ee1<perfect>. A list of rel is available in Stanford Parser Manual (de Marneffe and Manning, 2008; Chang et al., 2009) .",
                "cite_spans": [
                    {
                        "start": 451,
                        "end": 478,
                        "text": "Marneffe and Manning, 2008;",
                        "ref_id": "BIBREF11"
                    },
                    {
                        "start": 479,
                        "end": 498,
                        "text": "Chang et al., 2009)",
                        "ref_id": "BIBREF3"
                    }
                ],
                "ref_spans": [
                    {
                        "start": 285,
                        "end": 293,
                        "text": "Figure 1",
                        "ref_id": "FIGREF0"
                    }
                ],
                "eq_spans": [],
                "section": "Problem Definition",
                "sec_num": "2"
            },
            {
                "text": "Definition: Opinion Judgment The opinion judgment op(r), generated by the proposed system, indicates whether the corresponding dependency relation r is opinionated, and \uf07b \uf07d false true r op , ) ( \uf0ce . For example, when r = nmod(\u6210\u529f <success>, \u5706\u6ee1<perfect>), op(r) =",
                "cite_spans": [],
                "ref_spans": [],
                "eq_spans": [],
                "section": "Problem Definition",
                "sec_num": "2"
            },
            {
                "text": "Definition: Gold Opinion Judgment The gold opinion judgment, generated by mapping from manually annotated data, indicates whether the corresponding dependency relation r is opinionated, and",
                "cite_spans": [],
                "ref_spans": [],
                "eq_spans": [],
                "section": "true.",
                "sec_num": null
            },
            {
                "text": "\uf07b \uf07d false true r gop , ) ( \uf0ce .",
                "cite_spans": [],
                "ref_spans": [],
                "eq_spans": [],
                "section": "true.",
                "sec_num": null
            },
            {
                "text": "The gold answers come from the annotations on Chinese Treebank 5.1. In a parsing tree T of the sentence S, generated by the Stanford parser, an in-ordered set of tree nodes O = {o 1 , o 2 , \u2026} is used to draw a parsing tree for the annotation process, and its corresponding order, i.e., its index, is used as the node ID to record the annotations.",
                "cite_spans": [],
                "ref_spans": [],
                "eq_spans": [],
                "section": "true.",
                "sec_num": null
            },
            {
                "text": "The way we annotate an opinion relation on a parsing tree is annotating an opinion trio (Ku et al., 2009 Note that because the annotation of trios is on nodes of parsing trees, which appear inorderly, o left will always appear before o right in a sentence, and keeping this in mind will help understand the meaning of each inter-word relation t.",
                "cite_spans": [
                    {
                        "start": 88,
                        "end": 104,
                        "text": "(Ku et al., 2009",
                        "ref_id": "BIBREF7"
                    }
                ],
                "ref_spans": [],
                "eq_spans": [],
                "section": "true.",
                "sec_num": null
            },
            {
                "text": "Now for the sentence S, we have its parsing tree T, the annotated opinion trios Tri(S) on it, and its dependency relations Rdep(S). The next step is to mark the op(r) on Rdep(S) according to its corresponding Tri(S). For each trio tri, if any descendent of its left node o left and any descendent of its right node o right together build a relation ) (S Rdep r \uf0ce , the opinion judgment of gop(r) of the relation r is set to true. Otherwise, gop(r) is set to false. Now we have gop(r) for each r in Rdep(S), our goal is to find good methods to generate op(r) so that it can predict gop(r) as precisely as possible. We propose methods to achieve this goal in Section 3.",
                "cite_spans": [],
                "ref_spans": [],
                "eq_spans": [],
                "section": "true.",
                "sec_num": null
            },
            {
                "text": "As mentioned, our goal is to predict opinion dependency relations as precisely as possible. However, to use more readable materials, opinion trios are first annotated on Chinese Treebank 5.1, and then they are mapped to the corresponding dependency relations. Before the aligning process, we use the annotated trios for training to predict the opinion trios in Section 3.1. Using these predict trios for opinion analysis shall show the performance before the aligning process. After that, the aligned depen-dency relations, i.e., the gold opinion dependency relations are adopted for training to predict the opinion dependency relations in Section 3.2. Because the parsing tree and the dependency tree are generated by the same parser, we can always align them by the provided word ID numbers.",
                "cite_spans": [],
                "ref_spans": [],
                "eq_spans": [],
                "section": "Methods",
                "sec_num": "3"
            },
            {
                "text": "After prediction, the opinion dependency relations are available, and they can provide necessary information for many applications. However, we go one step further to test whether they benefit the opinion analysis. To fulfill this purpose, a basic method which uses the opinion dependency relations to extract opinionated sentences and determine their polarities is proposed in Section 3.3.",
                "cite_spans": [],
                "ref_spans": [],
                "eq_spans": [],
                "section": "Methods",
                "sec_num": "3"
            },
            {
                "text": "We predict the opinion trios by the sequential labeling model Conditional Random Field (CRF, Lafferty et al., 2001) . In a parsing tree, the tag of the internal node is the syntactic structure of its sub-tree, and the tag of the leaf node contains its part of speech and the content word. For each node, tags of its first four children (the first level), first four children of them (the second level), and their three children are used as features of this node. Features of its siblings (the window size is five) are considered, too.",
                "cite_spans": [
                    {
                        "start": 87,
                        "end": 115,
                        "text": "(CRF, Lafferty et al., 2001)",
                        "ref_id": null
                    }
                ],
                "ref_spans": [],
                "eq_spans": [],
                "section": "Predicting Opinion Trios",
                "sec_num": "3.1"
            },
            {
                "text": "The labels l we would like the CRF to predict labels for each node, which are N or labels of the form t-C, where",
                "cite_spans": [],
                "ref_spans": [],
                "eq_spans": [],
                "section": "Predicting Opinion Trios",
                "sec_num": "3.1"
            },
            {
                "text": "Rpt t \uf0ce , } , { R L C \uf03d , L",
                "cite_spans": [],
                "ref_spans": [],
                "eq_spans": [],
                "section": "Predicting Opinion Trios",
                "sec_num": "3.1"
            },
            {
                "text": "indicates that the current node is o left in some opinion trio and R indicates o right . The label N indicates that the current node does not belong to any Tri tri \uf0ce . The cardinality of the set Rpt is five, so that a total of 11 labels are used in CRF. CRF++ 1 is selected for experiments.",
                "cite_spans": [],
                "ref_spans": [],
                "eq_spans": [],
                "section": "Predicting Opinion Trios",
                "sec_num": "3.1"
            },
            {
                "text": "After aligning the opinion trios to the dependency relations, we will have gop(r) for each one of them. In the previous research, usually only some relations were selected for opinion analysis. No statistical numbers showed the connection between the dependency relations and the opinions. We believe that it is because the opinion annotation on dependency relations is more difficult than on words, sentences, or documents. However, because of this alignment, we are able to see the distribution of different dependency relations in opinion sentences and opinion segments (opinion trios).",
                "cite_spans": [],
                "ref_spans": [],
                "eq_spans": [],
                "section": "Predicting Opinion Dependency Relations",
                "sec_num": "3.2"
            },
            {
                "text": "We then predict opinion dependency relations based on these distributions: the op(r) of the relation r is set to true when its corresponding gop(r) appears massively frequently to be true in opinion sentences. To make this method reasonable, the assumption that there are no opinion trios in non-opinionated sentences must hold. A similar assumption that there are no opinion segments in non-opinionated sentences was made when annotating the NTCIR MOAT corpus, too (Seki et al., 2008) . Under this assumption, the relation that is in most case opinionated in opinion sentences is also in most case opinionated in all sentences. We believe that this assumption holds because intuitively if there is an opinion segment in one sentence, this sentence should be opinionated.",
                "cite_spans": [
                    {
                        "start": 466,
                        "end": 485,
                        "text": "(Seki et al., 2008)",
                        "ref_id": "BIBREF15"
                    }
                ],
                "ref_spans": [],
                "eq_spans": [],
                "section": "Predicting Opinion Dependency Relations",
                "sec_num": "3.2"
            },
            {
                "text": "In the previous research, relations were usually extracted automatically and then were used in various applications. As these relations are available after the prediction (or alignment) and as our purpose is to provide easy to use opinion dependency relations for further applications, we simply design rules for these relations in opinion analysis to show the baseline enhancement of using them.",
                "cite_spans": [],
                "ref_spans": [],
                "eq_spans": [],
                "section": "Using Syntactic Information for Opinion Extraction",
                "sec_num": "3.3"
            },
            {
                "text": "In the past, Ku et al. (2009) have conducted rule based experiments for opinion trios. They designed formula for trios of each",
                "cite_spans": [
                    {
                        "start": 13,
                        "end": 29,
                        "text": "Ku et al. (2009)",
                        "ref_id": "BIBREF7"
                    }
                ],
                "ref_spans": [],
                "eq_spans": [],
                "section": "Using opinion trios",
                "sec_num": "3.3.1"
            },
            {
                "text": ". Therefore, we adopted their rules on our augmentative experiment materials. We define the opinion scoring function S(.), and its output opinion score varies with the input variables. These rules are shown by trio types as follows. ",
                "cite_spans": [],
                "ref_spans": [],
                "eq_spans": [],
                "section": "Rpt t \uf0ce",
                "sec_num": null
            },
            {
                "text": "o S o S o o S o S SIGN o S SIGN o S o o S o S o S \uf02b \uf03d \uf0b4 \uf0b4 \uf03d \uf0b9 \uf0b9 (3)",
                "cite_spans": [],
                "ref_spans": [],
                "eq_spans": [],
                "section": "Rpt t \uf0ce",
                "sec_num": null
            },
            {
                "text": "\uf06c Verb-Complement Type: The scoring function for trios of this type is defined the same as that of a Subjective-Predicate type in Formula (2). The complement node is the deciding factor of the opinion score.",
                "cite_spans": [],
                "ref_spans": [],
                "eq_spans": [],
                "section": "Rpt t \uf0ce",
                "sec_num": null
            },
            {
                "text": "The usages of opinion dependency relations were seen in several researches (Bikel and Castelli, 2008) . In these researches, rules for a small number of major dependency relations were proposed in different papers but they were not listed together for a better utilization. Some rules were not ever mentioned in pervious researches. Instead, all relations are analyzed in this paper. For each relation r of which gop(r) equals true (when gold opinion relations are used for opinion analysis) or op(r) equals true (when predicted opinion relations are used for opinion analysis), we calculate its opinion score ops(r). Let RM(w) be a function to return the dependency relations of word w's modifiers one at a time, n is the total number of relations RM(w) returns, and S(.) is also the defined opinion scoring function then ops(r) is defined as in Formula (4).",
                "cite_spans": [
                    {
                        "start": 75,
                        "end": 101,
                        "text": "(Bikel and Castelli, 2008)",
                        "ref_id": "BIBREF1"
                    }
                ],
                "ref_spans": [],
                "eq_spans": [],
                "section": "Using opinion dependency relations",
                "sec_num": "3.3.2"
            },
            {
                "text": "\uf0e5 \uf02b \uf03d )) ( ( 1 ) , , ( ) ( m m h w RM ops n w w rel S r ops (4)",
                "cite_spans": [],
                "ref_spans": [],
                "eq_spans": [],
                "section": "Using opinion dependency relations",
                "sec_num": "3.3.2"
            },
            {
                "text": "That is, the opinion score of a dependency relation is an average of the aggregate scores of its descendent dependency relations. In practice, we design different rules for calculating opinion scores by the current relation type rel in S(.). Here to simplify the problem, we adopted Formula (1) and treated w m as o left and w h as o right in it.",
                "cite_spans": [],
                "ref_spans": [],
                "eq_spans": [],
                "section": "Using opinion dependency relations",
                "sec_num": "3.3.2"
            },
            {
                "text": "Though there were researches which predicted opinion dependency relations, they did not predict directly from the parsing results. Instead, they predicted from documents or sentences according to the context and a large quantity of training instances were needed. They did not predict on all dependency relations either. Therefore, there is no existing dataset containing correct opinion labels on dependency relations. In this section, we describe how to generate opinionated syntactic dataset on parsing trees, and align the annotated labels to dependency trees. After that, qualitative and quantitative analyses of opinion dependency relations are provided. At the end, we discuss the evaluation results of the proposed methods.",
                "cite_spans": [],
                "ref_spans": [],
                "eq_spans": [],
                "section": "Experiments",
                "sec_num": "4"
            },
            {
                "text": "To use the Stanford parser as our tool to generate dependency tree for experimental sentences and to avoid errors as possible, we adopted Chinese Treebank 5.1 as experiment materials. Sentences in Chinese Treebank are already segmented and part of speech tagged, and its tagging set is the same with the one Stanford parser uses. Therefore, the Stanford parser can take the data from the Chinese Treebank to generate more accurate dependency trees.",
                "cite_spans": [],
                "ref_spans": [],
                "eq_spans": [],
                "section": "Data Set and Preprocessing",
                "sec_num": "4.1"
            },
            {
                "text": "The dataset Chinese Treebank 5.1 contains 507,222 words, 824,983 Hanzi, 18,782 sentences, and 890 data files. For the opinion analysis experiments, opinionated labels, i.e., opinionated, non-opinionated, positive, neutral, negative, were annotated on all sentences in Chinese Opinion Treebank. Afterward 57,706 trios were annotated on the parsing trees of gold opinion sentences, i.e., sentences which were annotated as opinionated. Methods for generating the gold opinion sentences proposed by were adopted.",
                "cite_spans": [],
                "ref_spans": [],
                "eq_spans": [],
                "section": "Data Set and Preprocessing",
                "sec_num": "4.1"
            },
            {
                "text": "Next, the Stanford parser took all sentences in Chinese Treebank as input to generate their dependency trees. A total of 416,581 dependency relations were generated, and 284,590 of them were in opinion sentences. Then the annotated trios were aligned to their corresponding dependency relations, and because trios were only annotated on opinionated sentences, the gop(r) of these aligned relations were set to true. At the end, a total of 54,753 relations gop(r) were set to true. Table 2 . Statistics of structural trios. Table 1 shows the distribution of the opinion and polarity labels. Table 2 shows the statistics of trios. Trios of the Substantive-Modifier and Verb-Object types are the majority in opinion sentences, while trios of the Verb-Complement type are few. Table 3 further shows the distribution of dependency relations. It shows that previously the most adopted dependency relations for opinion analysis, e.g., amod (adjective modifier) or advmod (adverb modifier), do not certainly bear opinions or appear in opinion sentences. In Section 4.3, we will further test the performance of finding the opinionated relations with the help of the opinion word dictionary, which was also widely adopted by previous work (Feng et al., 2009) .",
                "cite_spans": [
                    {
                        "start": 1229,
                        "end": 1248,
                        "text": "(Feng et al., 2009)",
                        "ref_id": "BIBREF5"
                    }
                ],
                "ref_spans": [
                    {
                        "start": 481,
                        "end": 488,
                        "text": "Table 2",
                        "ref_id": null
                    },
                    {
                        "start": 523,
                        "end": 530,
                        "text": "Table 1",
                        "ref_id": null
                    },
                    {
                        "start": 590,
                        "end": 597,
                        "text": "Table 2",
                        "ref_id": null
                    },
                    {
                        "start": 773,
                        "end": 780,
                        "text": "Table 3",
                        "ref_id": null
                    }
                ],
                "eq_spans": [],
                "section": "Data Set and Preprocessing",
                "sec_num": "4.1"
            },
            {
                "text": "In this section, results of predicting opinion trios by CRF mentioned in Section 3.1 are shown. We first predicted the appearance of o left and o right in trios, and then predicted the trio type",
                "cite_spans": [],
                "ref_spans": [],
                "eq_spans": [],
                "section": "Evaluation of Opinion Trio Prediction",
                "sec_num": "4.2"
            },
            {
                "text": "for each trio. The performance in Table 4 is not promising. Therefore, we consider the structure of trios, that is, o left and o right should appear as an ordered pair, and otherwise the label was viewed as illegal. The performance is shown in Table  5 . Table 5 shows that all predicted trios were opinionated, and this tells that some opinion trios are of certain structures, but not all of them. We observed that the precisions 1.00 came from the collocations of specific words and structures, while the low recalls were from other trios which were not identified. However, these results still confirmed that we can find opinion trios by phrase structures and they may benefit in the opinion analysis process. Table 3 . Distributions of dependency relations and opinion dependency relations.",
                "cite_spans": [],
                "ref_spans": [
                    {
                        "start": 34,
                        "end": 41,
                        "text": "Table 4",
                        "ref_id": null
                    },
                    {
                        "start": 244,
                        "end": 252,
                        "text": "Table  5",
                        "ref_id": null
                    },
                    {
                        "start": 255,
                        "end": 262,
                        "text": "Table 5",
                        "ref_id": null
                    },
                    {
                        "start": 713,
                        "end": 720,
                        "text": "Table 3",
                        "ref_id": null
                    }
                ],
                "eq_spans": [],
                "section": "Rpt t \uf0ce",
                "sec_num": null
            },
            {
                "text": "(A: type of dependency relations (rel); B: total occurrences in generated dependency trees; C: total occurrence in generated dependency trees of opinions; D: total occurrence in generated dependency trees of opinions when it bears opinions (gop(r) equals true); E: percentage that this relation appears in generated dependency trees of opinions; F: percentage that this relation appears in generated dependency trees of opinions when it bears opinions (gop(r) equals true).)",
                "cite_spans": [],
                "ref_spans": [],
                "eq_spans": [],
                "section": "Rpt t \uf0ce",
                "sec_num": null
            },
            {
                "text": "To predict which dependency relations are opinionated, we start with analyzing the distribution of them. Table 3 presented the distribution of dependency relations. The percentage of a relation appearing in dependency trees of opinion sentences when bearing opinions (gop(r) equals true), i.e., the value in F column, is taken as the support value. The support value indicates that in what degree this relation bears opinions. If the support value is high, it is confident to say that the relation is opinionated; otherwise, considering the content words is necessary. This idea conforms to the previous observation in Section 4.2: some of the opinions are structural, but not all of them. According to the support value, dependency relations were divided into four categories. The Chinese opinion word dictionary NTUSD is involved to help identify opinion dependency relations when the support value is not high. The selecting criteria are listed as follows. \uf06c Very supportive: with the support value above 0.8, e.g., dvpmod. Relations in this category are viewed as opinionated and their gop(r) are automatically set to true. \uf06c Supportive: with the support value above 0.35 but lower than 0. 8, e.g., pass, dobj, npsubj, ba, top, nsubj, neg, amod, rcmod Table 6 . Performance of predicting opinion dependency relations.",
                "cite_spans": [
                    {
                        "start": 1194,
                        "end": 1255,
                        "text": "8, e.g., pass, dobj, npsubj, ba, top, nsubj, neg, amod, rcmod",
                        "ref_id": null
                    }
                ],
                "ref_spans": [
                    {
                        "start": 105,
                        "end": 112,
                        "text": "Table 3",
                        "ref_id": null
                    },
                    {
                        "start": 1256,
                        "end": 1263,
                        "text": "Table 6",
                        "ref_id": null
                    }
                ],
                "eq_spans": [],
                "section": "Evaluation of Opinion Dependency Relation Prediction",
                "sec_num": "4.3"
            },
            {
                "text": "The results of two experiment settings are listed: prediction performed on all dependency relations and on only modification-related dependency relations (in the form of lex-mod, e.g., amod, rcmod, etc.) The later are the relations adopted in many previous researches. Table 6 shows the performance of predicting opinion dependency relations. It indicates that if only modification related relations were considered, the f-score dropped nearly half because more than half of the opinion dependency relations were expelled in this case. In other word, results show that predicting on all relations instead of taking only modificationrelated dependency relations as clues can capture more opinion relations, and hence the prediction of opinion relations is necessary.",
                "cite_spans": [],
                "ref_spans": [
                    {
                        "start": 269,
                        "end": 276,
                        "text": "Table 6",
                        "ref_id": null
                    }
                ],
                "eq_spans": [],
                "section": "Evaluation of Opinion Dependency Relation Prediction",
                "sec_num": "4.3"
            },
            {
                "text": "In this section, predicted opinion trios and predicted opinion dependency relations were utilized in an opinion extraction system. In order to make use of these structural cues, opinion analysis methods proposed by were selected. Their methods calculated opinion scores of sentences from characters and words accumulatively, so syntactic cues can be added in and function jointly. Five settings for opinion analysis were experimented: \uf06c C+W+N: characters, words, and negations were used as cues for calculating opinion scores. It was the original method proposed by Ku et al. \uf06c C+W+N+goldTrio: annotated opinion trios were utilized additionally. \uf06c C+W+N+Trio: predicted opinion trios were utilized additionally. \uf06c C+W+N+goldDep: opinion dependency relations aligned from the annotated trios were utilized additionally. \uf06c C+W+N+Dep: predicted opinion dependency relations were utilized additionally. The results were shown in Table 7 . The performance of the opinion extraction improves 10.40% (0.7162->0.7993) when utilizing opinion trios and 8.66% (0.7162->0.7782) when utilizing opinion dependency relations. These results clearly indicate that the syntactic information benefit opinion analysis. Because of the possible information loss in the automatic alignment process, that the performance of using trios is a little better than using dependency relations matches our expectation. Table 7 . Performance of using syntactic information for opinion analysis.",
                "cite_spans": [],
                "ref_spans": [
                    {
                        "start": 925,
                        "end": 932,
                        "text": "Table 7",
                        "ref_id": null
                    },
                    {
                        "start": 1388,
                        "end": 1395,
                        "text": "Table 7",
                        "ref_id": null
                    }
                ],
                "eq_spans": [],
                "section": "Evaluation of Opinion Extraction Using Predicted Opinion Trios and Dependency Relations",
                "sec_num": "4.4"
            },
            {
                "text": "For all we know, no previous work has annotated opinion information on all dependency relations, or mapped annotated opinionated structures to dependency relations on a large quantity of documents or sentences. Therefore, to the best of our knowledge, no statistically analysis of opinion dependency relations involving manually annotations has been conducted. Researchers designed ruled or extracted dependency relations as features for opinion analysis based on their linguistic knowledge (Qiu et al., 2011 ). Yet there are still several lines of related work, including (i) opinion analysis (ii) opinion corpora (iii) syntactic information. Several dozen papers have been published on the topic of opinion analysis. Two general approaches have been proposed previously. They are machine learning approaches and heuristicrule approaches. For both approaches, syntactic structures could be utilized. For the former, they can be used as features (Abbasi et al., 2008) ; for the later, rules can be designed according to them (Ku et al., 2009) . We can see from the previous work that syntactic structures can help to enhance the performance.",
                "cite_spans": [
                    {
                        "start": 491,
                        "end": 508,
                        "text": "(Qiu et al., 2011",
                        "ref_id": "BIBREF14"
                    },
                    {
                        "start": 946,
                        "end": 967,
                        "text": "(Abbasi et al., 2008)",
                        "ref_id": "BIBREF0"
                    },
                    {
                        "start": 1025,
                        "end": 1042,
                        "text": "(Ku et al., 2009)",
                        "ref_id": "BIBREF7"
                    }
                ],
                "ref_spans": [],
                "eq_spans": [],
                "section": "Related Work",
                "sec_num": "5"
            },
            {
                "text": "As to the experimental corpora, some researchers managed to generate annotated materials and gold standards under constraints. Somasundaran (2007) annotated discourse information from meeting dialogs to train a sentiment model. MPQA annotated opinions and their sources (Wiebe et al., 2002) . NTCIR annotated opinions, polarities, sources, and targets for its multilingual opinion analysis task (MOAT, Seki et al., 2008) . However, none of them were annotated on materials with syntac-tic structures, and it caused the lack of analysis of opinion syntactic structures.",
                "cite_spans": [
                    {
                        "start": 127,
                        "end": 146,
                        "text": "Somasundaran (2007)",
                        "ref_id": "BIBREF16"
                    },
                    {
                        "start": 270,
                        "end": 290,
                        "text": "(Wiebe et al., 2002)",
                        "ref_id": "BIBREF17"
                    },
                    {
                        "start": 395,
                        "end": 420,
                        "text": "(MOAT, Seki et al., 2008)",
                        "ref_id": null
                    }
                ],
                "ref_spans": [],
                "eq_spans": [],
                "section": "Related Work",
                "sec_num": "5"
            },
            {
                "text": "Researchers have acquired syntactic structures (Zhou, 2008) , but few of them have tried to associate syntactic structures with opinions. The most similar previous work to ours was proposed by Ku et al. (2009) . Compared to it, the proposed process made the development of opinion dependency parser feasible. As dependency relations and the predicted opinion dependency relations are of the same form, no extra knowledge or integration is needed for the use of them.",
                "cite_spans": [
                    {
                        "start": 47,
                        "end": 59,
                        "text": "(Zhou, 2008)",
                        "ref_id": "BIBREF18"
                    },
                    {
                        "start": 193,
                        "end": 209,
                        "text": "Ku et al. (2009)",
                        "ref_id": "BIBREF7"
                    }
                ],
                "ref_spans": [],
                "eq_spans": [],
                "section": "Related Work",
                "sec_num": "5"
            },
            {
                "text": "The proposed new process is the main contribution of this paper. It annotated opinion syntactic structures on phrase structure trees, which are more readable for annotators, and aligned these structures to grammatical structures, which facilitates their usage. Chinese Treebank was selected as the source of phrase structure trees, and dependency relations as the grammatical structures. They are both widely used in natural language processing.",
                "cite_spans": [],
                "ref_spans": [],
                "eq_spans": [],
                "section": "Conclusions and Future Work",
                "sec_num": "6"
            },
            {
                "text": "Though the experiments were implemented on Chinese materials, this process is language independent. It can be applied to materials in different languages without modifications.",
                "cite_spans": [],
                "ref_spans": [],
                "eq_spans": [],
                "section": "Conclusions and Future Work",
                "sec_num": "6"
            },
            {
                "text": "By predicting opinion dependency relations, we can say that a basic opinion dependency parser has been developed. Experiments have shown that the predicted opinion dependency relations are beneficial for opinion extraction. Although we still need a parser to generate syntactic structures, parsing is relatively a mature technique in natural language processing. For a comparably new research problem like opinion analysis, it is common that tools are not handy. The best of the proposed method is that it can function in a multilingual environment by incorporating a domain or language specific resources (here, NTUSD for Chinese).",
                "cite_spans": [],
                "ref_spans": [],
                "eq_spans": [],
                "section": "Conclusions and Future Work",
                "sec_num": "6"
            },
            {
                "text": "Through the alignment, we made a large quantity of opinion dependency relations available. According to their distributions shown in this paper, researchers can select suitable relations to use according to their diverse needs, such as extracting evaluative features in product reviews or comments, opinions or their polarities.",
                "cite_spans": [],
                "ref_spans": [],
                "eq_spans": [],
                "section": "Conclusions and Future Work",
                "sec_num": "6"
            },
            {
                "text": "http://crfpp.sourceforge.net/",
                "cite_spans": [],
                "ref_spans": [],
                "eq_spans": [],
                "section": "",
                "sec_num": null
            }
        ],
        "back_matter": [],
        "bib_entries": {
            "BIBREF0": {
                "ref_id": "b0",
                "title": "Sentiment analysis in multiple languages: Feature selection for opinion classification in Web forums",
                "authors": [
                    {
                        "first": "A",
                        "middle": [],
                        "last": "Abbasi",
                        "suffix": ""
                    },
                    {
                        "first": "H",
                        "middle": [],
                        "last": "Chen",
                        "suffix": ""
                    },
                    {
                        "first": "A",
                        "middle": [],
                        "last": "Salem",
                        "suffix": ""
                    }
                ],
                "year": 2008,
                "venue": "ACM Trans. Inf. Syst",
                "volume": "26",
                "issue": "",
                "pages": "1--34",
                "other_ids": {
                    "DOI": [
                        "10.1145/1361684"
                    ]
                },
                "num": null,
                "urls": [],
                "raw_text": "Abbasi, A., Chen, H., and Salem, A. 2008. Senti- ment analysis in multiple languages: Feature se- lection for opinion classification in Web forums. ACM Trans. Inf. Syst. 26, 3 (Jun. 2008), 1-34. DOI= http://doi.acm.org/10.1145/1361684.",
                "links": null
            },
            "BIBREF1": {
                "ref_id": "b1",
                "title": "Event Matching Using the Transitive Closure of Dependency Relations",
                "authors": [
                    {
                        "first": "D",
                        "middle": [
                            "M"
                        ],
                        "last": "Bikel",
                        "suffix": ""
                    },
                    {
                        "first": "V",
                        "middle": [],
                        "last": "Castelli",
                        "suffix": ""
                    }
                ],
                "year": 2008,
                "venue": "Proceedings of the 46th Annual Meeting on Association for Computational Linguistics",
                "volume": "",
                "issue": "",
                "pages": "145--148",
                "other_ids": {},
                "num": null,
                "urls": [],
                "raw_text": "Bikel, D. M. and Castelli, V. 2008. Event Matching Using the Transitive Closure of Dependency Re- lations. Proceedings of the 46th Annual Meeting on Association for Computational Linguistics, pages 145-148.",
                "links": null
            },
            "BIBREF2": {
                "ref_id": "b2",
                "title": "Identifying Expressions of Opinion in Context",
                "authors": [
                    {
                        "first": "E",
                        "middle": [],
                        "last": "Breck",
                        "suffix": ""
                    },
                    {
                        "first": "Y",
                        "middle": [],
                        "last": "Choi",
                        "suffix": ""
                    },
                    {
                        "first": "C",
                        "middle": [],
                        "last": "Cardie",
                        "suffix": ""
                    }
                ],
                "year": 2007,
                "venue": "Proceedings of the 20th International Joint Conferences on Artificial Intelligence",
                "volume": "",
                "issue": "",
                "pages": "2683--2688",
                "other_ids": {},
                "num": null,
                "urls": [],
                "raw_text": "Breck, E., Choi, Y. and Cardie, C. 2007. Identify- ing Expressions of Opinion in Context. Proceed- ings of the 20th International Joint Conferences on Artificial Intelligence, pages 2683-2688.",
                "links": null
            },
            "BIBREF3": {
                "ref_id": "b3",
                "title": "Discriminative Reordering with Chinese Grammatical Relations Features",
                "authors": [
                    {
                        "first": "P.-C",
                        "middle": [],
                        "last": "Chang",
                        "suffix": ""
                    },
                    {
                        "first": "H",
                        "middle": [],
                        "last": "Tseng",
                        "suffix": ""
                    },
                    {
                        "first": "D",
                        "middle": [],
                        "last": "Jurafsky",
                        "suffix": ""
                    },
                    {
                        "first": "C",
                        "middle": [
                            "D"
                        ],
                        "last": "Manning",
                        "suffix": ""
                    }
                ],
                "year": 2009,
                "venue": "Proceedings of the Third Workshop on Syntax and Structure in Statistical Translation",
                "volume": "",
                "issue": "",
                "pages": "51--59",
                "other_ids": {},
                "num": null,
                "urls": [],
                "raw_text": "Chang, P.-C., Tseng, H., Jurafsky, D. and Manning C. D. 2009. Discriminative Reordering with Chinese Grammatical Relations Features. Pro- ceedings of the Third Workshop on Syntax and Structure in Statistical Translation, pages 51-59.",
                "links": null
            },
            "BIBREF4": {
                "ref_id": "b4",
                "title": "Searching Question by Identifying Question Topic and Question Focus",
                "authors": [
                    {
                        "first": "H",
                        "middle": [],
                        "last": "Doan",
                        "suffix": ""
                    },
                    {
                        "first": "Y",
                        "middle": [],
                        "last": "Cao",
                        "suffix": ""
                    },
                    {
                        "first": "C.-Y",
                        "middle": [],
                        "last": "Lin",
                        "suffix": ""
                    },
                    {
                        "first": "Y",
                        "middle": [],
                        "last": "Yu",
                        "suffix": ""
                    }
                ],
                "year": 2008,
                "venue": "Proceedings of the 46th Annual Meeting on Association for Computational Linguistics",
                "volume": "",
                "issue": "",
                "pages": "156--164",
                "other_ids": {},
                "num": null,
                "urls": [],
                "raw_text": "Doan, H., Cao, Y., Lin, C.-Y. and Yu, Y. 2008. Searching Question by Identifying Question Topic and Question Focus. Proceedings of the 46th Annual Meeting on Association for Compu- tational Linguistics, pages 156-164.",
                "links": null
            },
            "BIBREF5": {
                "ref_id": "b5",
                "title": "Chinese Blog Clustering by Hidden Sentiment Factors. ADMA",
                "authors": [
                    {
                        "first": "S",
                        "middle": [],
                        "last": "Feng",
                        "suffix": ""
                    },
                    {
                        "first": "D",
                        "middle": [],
                        "last": "Wang",
                        "suffix": ""
                    },
                    {
                        "first": "G",
                        "middle": [],
                        "last": "Yu",
                        "suffix": ""
                    },
                    {
                        "first": "C",
                        "middle": [],
                        "last": "Yang",
                        "suffix": ""
                    },
                    {
                        "first": "N",
                        "middle": [],
                        "last": "Yang",
                        "suffix": ""
                    }
                ],
                "year": 2009,
                "venue": "",
                "volume": "5678",
                "issue": "",
                "pages": "140--151",
                "other_ids": {},
                "num": null,
                "urls": [],
                "raw_text": "Feng, S., Wang, D., Yu, G., Yang, C. and Yang, N. 2009. Chinese Blog Clustering by Hidden Sen- timent Factors. ADMA, Vol. 5678, Springer (2009), pages 140-151.",
                "links": null
            },
            "BIBREF6": {
                "ref_id": "b6",
                "title": "Mining Opinions from the Web: Beyond Relevance Retrieval",
                "authors": [
                    {
                        "first": "L.-W",
                        "middle": [],
                        "last": "Ku",
                        "suffix": ""
                    },
                    {
                        "first": "H.-H",
                        "middle": [],
                        "last": "Chen",
                        "suffix": ""
                    }
                ],
                "year": 2007,
                "venue": "Journal of American Society for Information Science and Technology, Special Issue on Mining Web Resources for Enhancing Information Retrieval",
                "volume": "58",
                "issue": "12",
                "pages": "1838--1850",
                "other_ids": {},
                "num": null,
                "urls": [],
                "raw_text": "Ku, L.-W. and Chen, H.-H. 2007. Mining Opinions from the Web: Beyond Relevance Retrieval. Journal of American Society for Information Science and Technology, Special Issue on Min- ing Web Resources for Enhancing Information Retrieval, 58(12), 1838-1850.",
                "links": null
            },
            "BIBREF7": {
                "ref_id": "b7",
                "title": "Using Morphological and Syntactic Structures for Chinese Opinion Analysis",
                "authors": [
                    {
                        "first": "L.-W",
                        "middle": [],
                        "last": "Ku",
                        "suffix": ""
                    },
                    {
                        "first": "T.-H",
                        "middle": [],
                        "last": "Huang",
                        "suffix": ""
                    },
                    {
                        "first": "H.-H",
                        "middle": [],
                        "last": "Chen",
                        "suffix": ""
                    }
                ],
                "year": 2009,
                "venue": "Proceedings of Conference on Empirical Methods in Natural Language Processing",
                "volume": "",
                "issue": "",
                "pages": "1260--1269",
                "other_ids": {},
                "num": null,
                "urls": [],
                "raw_text": "Ku, L.-W., Huang, T.-H. and Chen, H.-H. 2009. Using Morphological and Syntactic Structures for Chinese Opinion Analysis. Proceedings of Conference on Empirical Methods in Natural Language Processing, pages 1260-1269.",
                "links": null
            },
            "BIBREF8": {
                "ref_id": "b8",
                "title": "Test Collection Selection and Gold Standard Generation for a Multiply-Annotated Opinion Corpus",
                "authors": [
                    {
                        "first": "L.-W",
                        "middle": [],
                        "last": "Ku",
                        "suffix": ""
                    },
                    {
                        "first": "Y.-S",
                        "middle": [],
                        "last": "Lo",
                        "suffix": ""
                    },
                    {
                        "first": "Chen H.-H",
                        "middle": [],
                        "last": "",
                        "suffix": ""
                    }
                ],
                "year": 2007,
                "venue": "Proceedings of the 45th Annual Meeting on Association for Computational Linguistics",
                "volume": "",
                "issue": "",
                "pages": "89--92",
                "other_ids": {},
                "num": null,
                "urls": [],
                "raw_text": "Ku, L.-W., Lo, Y.-S. and Chen H.-H. 2007. Test Collection Selection and Gold Standard Genera- tion for a Multiply-Annotated Opinion Corpus. Proceedings of the 45th Annual Meeting on As- sociation for Computational Linguistics, pages 89-92.",
                "links": null
            },
            "BIBREF9": {
                "ref_id": "b9",
                "title": "Conditional Random Fields: Probabilistic Models for Segmenting and Labeling Sequence Data",
                "authors": [
                    {
                        "first": "J",
                        "middle": [],
                        "last": "Lafferty",
                        "suffix": ""
                    },
                    {
                        "first": "A",
                        "middle": [],
                        "last": "Mccallum",
                        "suffix": ""
                    },
                    {
                        "first": "F",
                        "middle": [],
                        "last": "Pereira",
                        "suffix": ""
                    }
                ],
                "year": 2001,
                "venue": "Proceedings of International Conference on Machine Learning",
                "volume": "",
                "issue": "",
                "pages": "282--289",
                "other_ids": {},
                "num": null,
                "urls": [],
                "raw_text": "Lafferty, J., McCallum, A. and Pereira, F. 2001. Conditional Random Fields: Probabilistic Mod- els for Segmenting and Labeling Sequence Data. Proceedings of International Conference on Ma- chine Learning, pages 282-289.",
                "links": null
            },
            "BIBREF10": {
                "ref_id": "b10",
                "title": "Rated Aspect Summarization of Short Comments",
                "authors": [
                    {
                        "first": "Y",
                        "middle": [],
                        "last": "Lu",
                        "suffix": ""
                    },
                    {
                        "first": "C",
                        "middle": [
                            "X"
                        ],
                        "last": "Zhai",
                        "suffix": ""
                    },
                    {
                        "first": "N",
                        "middle": [],
                        "last": "Sundaresan",
                        "suffix": ""
                    }
                ],
                "year": 2009,
                "venue": "Proceedings of 18 th International World Wide Web Conference",
                "volume": "",
                "issue": "",
                "pages": "131--140",
                "other_ids": {},
                "num": null,
                "urls": [],
                "raw_text": "Lu, Y., Zhai, C.X. and Sundaresan, N. 2009. Rated Aspect Summarization of Short Comments. Pro- ceedings of 18 th International World Wide Web Conference, pages 131-140.",
                "links": null
            },
            "BIBREF11": {
                "ref_id": "b11",
                "title": "Stanford typed dependencies manual",
                "authors": [
                    {
                        "first": ", M.-C",
                        "middle": [],
                        "last": "De Marneffe",
                        "suffix": ""
                    },
                    {
                        "first": "C",
                        "middle": [
                            "D"
                        ],
                        "last": "Manning",
                        "suffix": ""
                    }
                ],
                "year": 2008,
                "venue": "",
                "volume": "",
                "issue": "",
                "pages": "",
                "other_ids": {},
                "num": null,
                "urls": [],
                "raw_text": "de Marneffe, M.-C. and Manning, C. D. 2008. Stan- ford typed dependencies manual. Technichal re- port. http://nlp.stanford.edu/software/depend encies_manual.pdf",
                "links": null
            },
            "BIBREF12": {
                "ref_id": "b12",
                "title": "Thumbs up? Sentiment classification using machine learning techniques",
                "authors": [
                    {
                        "first": "B",
                        "middle": [],
                        "last": "Pang",
                        "suffix": ""
                    },
                    {
                        "first": "L",
                        "middle": [],
                        "last": "Lee",
                        "suffix": ""
                    },
                    {
                        "first": "S",
                        "middle": [],
                        "last": "Vaithyanathan",
                        "suffix": ""
                    }
                ],
                "year": 2002,
                "venue": "Proceedings of the 2002 Conference on Empirical Methods in Natural Language Processing",
                "volume": "",
                "issue": "",
                "pages": "79--86",
                "other_ids": {},
                "num": null,
                "urls": [],
                "raw_text": "Pang, B., Lee, L. and Vaithyanathan, S. 2002. Thumbs up? Sentiment classification using ma- chine learning techniques. Proceedings of the 2002 Conference on Empirical Methods in Natu- ral Language Processing, pages 79-86.",
                "links": null
            },
            "BIBREF13": {
                "ref_id": "b13",
                "title": "Incorporate the Syntactic. Knowledge in Opinion Mining in User-generated Content",
                "authors": [
                    {
                        "first": "G",
                        "middle": [],
                        "last": "Qiu",
                        "suffix": ""
                    },
                    {
                        "first": "C",
                        "middle": [],
                        "last": "Wang",
                        "suffix": ""
                    },
                    {
                        "first": "J",
                        "middle": [],
                        "last": "Bu",
                        "suffix": ""
                    },
                    {
                        "first": "K",
                        "middle": [],
                        "last": "Liu",
                        "suffix": ""
                    },
                    {
                        "first": "C",
                        "middle": [],
                        "last": "Chen",
                        "suffix": ""
                    }
                ],
                "year": 2008,
                "venue": "",
                "volume": "",
                "issue": "",
                "pages": "",
                "other_ids": {},
                "num": null,
                "urls": [],
                "raw_text": "Qiu, G., Wang, C., Bu, J., Liu, K. and Chen, C. 2008. Incorporate the Syntactic. Knowledge in Opinion Mining in User-generated Content. Pro- ceedings of NLPIX'08.",
                "links": null
            },
            "BIBREF14": {
                "ref_id": "b14",
                "title": "Opinion Word Expansion and Target Extraction through Double Propagation",
                "authors": [
                    {
                        "first": "G",
                        "middle": [],
                        "last": "Qiu",
                        "suffix": ""
                    },
                    {
                        "first": "B",
                        "middle": [],
                        "last": "Liu",
                        "suffix": ""
                    },
                    {
                        "first": "J",
                        "middle": [],
                        "last": "Bu",
                        "suffix": ""
                    },
                    {
                        "first": "C",
                        "middle": [],
                        "last": "Chen",
                        "suffix": ""
                    }
                ],
                "year": 2011,
                "venue": "Computational Linguistics",
                "volume": "37",
                "issue": "1",
                "pages": "",
                "other_ids": {},
                "num": null,
                "urls": [],
                "raw_text": "Qiu, G., Liu, B., Bu, J. and Chen, C. 2011. Opinion Word Expansion and Target Extraction through Double Propagation. Computational Linguistics, March 2011, Vol. 37, No. 1: 9.27",
                "links": null
            },
            "BIBREF15": {
                "ref_id": "b15",
                "title": "Overview of Multilingual Opinion Analysis Task at NTCIR-7",
                "authors": [
                    {
                        "first": "Y",
                        "middle": [],
                        "last": "Seki",
                        "suffix": ""
                    },
                    {
                        "first": "D",
                        "middle": [
                            "K"
                        ],
                        "last": "Evans",
                        "suffix": ""
                    },
                    {
                        "first": "L.-W",
                        "middle": [],
                        "last": "Ku",
                        "suffix": ""
                    },
                    {
                        "first": "L",
                        "middle": [],
                        "last": "Sun",
                        "suffix": ""
                    },
                    {
                        "first": "H.-H",
                        "middle": [],
                        "last": "Chen",
                        "suffix": ""
                    },
                    {
                        "first": "N",
                        "middle": [],
                        "last": "Kando",
                        "suffix": ""
                    }
                ],
                "year": 2008,
                "venue": "Proceedings of the 7th NTCIR Workshop Meeting on Evaluation of Information Access Technologies:Information Retrieval, Question Answering, and Cross-Lingual Information Access",
                "volume": "",
                "issue": "",
                "pages": "185--203",
                "other_ids": {},
                "num": null,
                "urls": [],
                "raw_text": "Seki, Y., D. K. Evans, L.-W. Ku, L. Sun, H.-H. Chen and N. Kando. 2008. Overview of Multi- lingual Opinion Analysis Task at NTCIR-7. Proceedings of the 7th NTCIR Workshop Meet- ing on Evaluation of Information Access Tech- nologies:Information Retrieval, Question Ans- wering, and Cross-Lingual Information Access, pages 185-203.",
                "links": null
            },
            "BIBREF16": {
                "ref_id": "b16",
                "title": "Detecting arguing and sentiment in meetings",
                "authors": [
                    {
                        "first": "S",
                        "middle": [],
                        "last": "Somasundaran",
                        "suffix": ""
                    },
                    {
                        "first": "J",
                        "middle": [],
                        "last": "Ruppenhofer",
                        "suffix": ""
                    },
                    {
                        "first": "J",
                        "middle": [],
                        "last": "Wiebe",
                        "suffix": ""
                    }
                ],
                "year": 2007,
                "venue": "Proceedings of the SIGdial Workshop on Discourse and Dialogue",
                "volume": "",
                "issue": "",
                "pages": "",
                "other_ids": {},
                "num": null,
                "urls": [],
                "raw_text": "Somasundaran, S., J. Ruppenhofer and J. Wiebe. 2007. Detecting arguing and sentiment in meet- ings. Proceedings of the SIGdial Workshop on Discourse and Dialogue 2007.",
                "links": null
            },
            "BIBREF17": {
                "ref_id": "b17",
                "title": "NRRC summer workshop on multi-perspective question answering, final report. ARDA NRRC Summer",
                "authors": [
                    {
                        "first": "J",
                        "middle": [],
                        "last": "Wiebe",
                        "suffix": ""
                    },
                    {
                        "first": "E",
                        "middle": [],
                        "last": "Breck",
                        "suffix": ""
                    },
                    {
                        "first": "C",
                        "middle": [],
                        "last": "Buckly",
                        "suffix": ""
                    },
                    {
                        "first": "C",
                        "middle": [],
                        "last": "Cardie",
                        "suffix": ""
                    },
                    {
                        "first": "P",
                        "middle": [],
                        "last": "Davis",
                        "suffix": ""
                    },
                    {
                        "first": "B",
                        "middle": [],
                        "last": "Fraser",
                        "suffix": ""
                    },
                    {
                        "first": "D",
                        "middle": [],
                        "last": "Litman",
                        "suffix": ""
                    },
                    {
                        "first": "D",
                        "middle": [],
                        "last": "Pierce",
                        "suffix": ""
                    },
                    {
                        "first": "E",
                        "middle": [],
                        "last": "Riloff",
                        "suffix": ""
                    },
                    {
                        "first": "T",
                        "middle": [],
                        "last": "Wilson",
                        "suffix": ""
                    }
                ],
                "year": 2002,
                "venue": "",
                "volume": "",
                "issue": "",
                "pages": "",
                "other_ids": {},
                "num": null,
                "urls": [],
                "raw_text": "Wiebe, J., E. Breck, C. Buckly, C. Cardie, P. Davis, B. Fraser, D. Litman, D. Pierce, E. Riloff and T. Wilson. 2002. NRRC summer workshop on mul- ti-perspective question answering, final report. ARDA NRRC Summer 2002 Workshop.",
                "links": null
            },
            "BIBREF18": {
                "ref_id": "b18",
                "title": "Automatic rule acquisition for Chinese intra-chunk relations",
                "authors": [
                    {
                        "first": "Q",
                        "middle": [],
                        "last": "Zhou",
                        "suffix": ""
                    }
                ],
                "year": 2008,
                "venue": "Proceedings of International Joint Conference of Natural Language Processing",
                "volume": "",
                "issue": "",
                "pages": "",
                "other_ids": {},
                "num": null,
                "urls": [],
                "raw_text": "Zhou, Q. 2008. Automatic rule acquisition for Chi- nese intra-chunk relations. Proceedings of Inter- national Joint Conference of Natural Language Processing (IJCNLP-2008).",
                "links": null
            }
        },
        "ref_entries": {
            "FIGREF0": {
                "text": "A sample dependency tree with three aligned opinion dependency relations.",
                "uris": null,
                "type_str": "figure",
                "num": null
            },
            "FIGREF1": {
                "text": "A sample parsing tree and opinion trios within the sentence inFigure 1are shown inFigure 2. The literal output of opinion trios are shown in",
                "uris": null,
                "type_str": "figure",
                "num": null
            },
            "FIGREF2": {
                "text": "In the trio tri = (3, NP-OBJ, \u5706\u6ee1, \u6210\u529f, Substantive-Modifier), triID = 3, o parent = NP-OBJ, o left =\u5706\u6ee1 (perfect), o right =\u6210\u529f(success), and t = Substantive-Modifier.",
                "uris": null,
                "type_str": "figure",
                "num": null
            },
            "FIGREF3": {
                "text": "A sample parsing tree with trios. 1, IP, \u6d3b\u52a8, VP, Subjective-Predicate 2, VP, \u53d6\u5f97, NP-OBJ, Verb-Object 3, NP-OBJ, \u5706\u6ee1, \u6210\u529f, Substantive-Modifier",
                "uris": null,
                "type_str": "figure",
                "num": null
            },
            "FIGREF4": {
                "text": "Figure 3. Opinion trios",
                "uris": null,
                "type_str": "figure",
                "num": null
            },
            "FIGREF5": {
                "text": "\uf06c",
                "uris": null,
                "type_str": "figure",
                "num": null
            },
            "TABREF1": {
                "type_str": "table",
                "html": null,
                "num": null,
                "text": "o left of this trio type modifies o right , so that the trio's opinion weight comes from the absolute opinion score of o left , while the opinion polarity is determined by the occurrence of negative o left or o right . If at least one of them is negative, the trio is negative, else it is positive. Predicate Type: o left of this trio type is a subject and o right is the action it performs, so that the action decides the opinion score of the trio. If the action is not an opinion or it is neutral, the subject determines the opinion score of this trio.",
                "content": "<table><tr><td>if</td><td>(</td><td colspan=\"2\">S</td><td>(</td><td colspan=\"4\">left o</td><td>)</td><td colspan=\"2\">\uf0b9</td><td>0</td><td/><td colspan=\"5\">and</td><td colspan=\"2\">S</td><td>(</td><td>o</td><td>right</td><td>)</td><td>\uf0b9</td><td>0</td><td>)</td><td>then</td></tr><tr><td/><td/><td colspan=\"11\">( o left left ) o S ( S else ( if</td><td colspan=\"5\">0 right o \uf03e</td><td colspan=\"3\">-and ) \uf03d</td><td>1 S \uf0b4 (</td><td>( right left ) o S o</td><td>) \uf03e</td><td>0</td><td>)</td><td>then</td><td>S</td><td>(</td><td>left o</td><td>right o</td><td>)</td><td>\uf03d</td><td>S</td><td>(</td><td>left o</td><td>)</td><td>(1)</td></tr><tr><td colspan=\"3\">else</td><td colspan=\"3\">S</td><td>(</td><td colspan=\"3\">left o</td><td colspan=\"4\">right o</td><td>)</td><td colspan=\"2\">\uf03d</td><td/><td>S</td><td>(</td><td>left o</td><td>)</td><td>\uf02b</td><td>S</td><td>(</td><td>o</td><td>right</td><td>)</td></tr><tr><td/><td/><td colspan=\"9\">else ( if S S (</td><td colspan=\"5\">( o o right left</td><td colspan=\"2\">) o</td><td colspan=\"3\">) ) 0 right \uf0b9</td><td>( then S \uf03d</td><td>( left S o</td><td>) o</td><td>left</td><td>o</td><td>right</td><td>)</td><td>\uf03d</td><td>S</td><td>(</td><td>o</td><td>right</td><td>)</td><td>(2)</td></tr><tr><td>if</td><td>(</td><td/><td>(</td><td/><td/><td colspan=\"2\">left</td><td>)</td><td/><td/><td colspan=\"2\">0</td><td colspan=\"5\">and</td><td/><td/><td>(</td><td>right</td><td>)</td><td>0</td><td>)</td></tr><tr><td/><td colspan=\"5\">then</td><td/><td/><td colspan=\"2\">(</td><td/><td colspan=\"2\">left</td><td/><td colspan=\"3\">right</td><td colspan=\"2\">)</td><td/><td>(</td><td>left</td><td>)</td><td>(</td><td>(</td><td>left</td><td>))</td><td>(</td><td>(</td><td>right</td><td>))</td></tr><tr><td/><td colspan=\"4\">else</td><td/><td/><td colspan=\"2\">(</td><td colspan=\"3\">left</td><td colspan=\"3\">right</td><td colspan=\"2\">)</td><td/><td/><td/><td>(</td><td>left</td><td>)</td><td>(</td><td>right</td><td>)</td></tr></table>"
            }
        }
    }
}