File size: 62,411 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
{
    "paper_id": "2020",
    "header": {
        "generated_with": "S2ORC 1.0.0",
        "date_generated": "2023-01-19T02:09:57.998697Z"
    },
    "title": "Annotation and Detection of Arguments in Tweets",
    "authors": [
        {
            "first": "Robin",
            "middle": [],
            "last": "Schaefer",
            "suffix": "",
            "affiliation": {
                "laboratory": "",
                "institution": "Applied Computational Linguistics University of Potsdam",
                "location": {
                    "settlement": "Potsdam",
                    "country": "Germany"
                }
            },
            "email": "robin.schaefer@uni-potsdam.de"
        },
        {
            "first": "Manfred",
            "middle": [],
            "last": "Stede",
            "suffix": "",
            "affiliation": {
                "laboratory": "",
                "institution": "Computational Linguistics University of Potsdam",
                "location": {
                    "settlement": "Potsdam",
                    "country": "Germany"
                }
            },
            "email": "stede@uni-potsdam.de"
        }
    ],
    "year": "",
    "venue": null,
    "identifiers": {},
    "abstract": "Notwithstanding the increasing role Twitter plays in modern political and social discourse, resources built for conducting argument mining on tweets remain limited. In this paper, we present a new corpus of German tweets annotated for argument components. To the best of our knowledge, this is the first corpus containing not only annotated full tweets but also argumentative spans within tweets. We further report first promising results using supervised classification (F1: 0.82) and sequence labeling (F1: 0.72) approaches. 2 Related Work Related work on tweet-based argument mining has focused on separating argumentative tweets from non-argumentative ones and on defining new Twitter-specific tasks.",
    "pdf_parse": {
        "paper_id": "2020",
        "_pdf_hash": "",
        "abstract": [
            {
                "text": "Notwithstanding the increasing role Twitter plays in modern political and social discourse, resources built for conducting argument mining on tweets remain limited. In this paper, we present a new corpus of German tweets annotated for argument components. To the best of our knowledge, this is the first corpus containing not only annotated full tweets but also argumentative spans within tweets. We further report first promising results using supervised classification (F1: 0.82) and sequence labeling (F1: 0.72) approaches. 2 Related Work Related work on tweet-based argument mining has focused on separating argumentative tweets from non-argumentative ones and on defining new Twitter-specific tasks.",
                "cite_spans": [],
                "ref_spans": [],
                "eq_spans": [],
                "section": "Abstract",
                "sec_num": null
            }
        ],
        "body_text": [
            {
                "text": "In recent years the field of argument mining, which focuses on the automatic identification of argument components and their relations in text, has developed substantially (Stede and Schneider, 2018) . However, while the majority of research concentrates on well-structured documents (Moens et al., 2007; Stab and Gurevych, 2014) , less work has been done on user-generated web content (Park and Cardie, 2014; Habernal and Gurevych, 2015) . This shortcoming poses a problem as systems trained on formal and edited texts tend to be inapt of extracting patterns from the more informal user-generated content (\u0160najder, 2016) .",
                "cite_spans": [
                    {
                        "start": 172,
                        "end": 199,
                        "text": "(Stede and Schneider, 2018)",
                        "ref_id": null
                    },
                    {
                        "start": 284,
                        "end": 304,
                        "text": "(Moens et al., 2007;",
                        "ref_id": "BIBREF14"
                    },
                    {
                        "start": 305,
                        "end": 329,
                        "text": "Stab and Gurevych, 2014)",
                        "ref_id": "BIBREF18"
                    },
                    {
                        "start": 386,
                        "end": 409,
                        "text": "(Park and Cardie, 2014;",
                        "ref_id": "BIBREF15"
                    },
                    {
                        "start": 410,
                        "end": 438,
                        "text": "Habernal and Gurevych, 2015)",
                        "ref_id": "BIBREF11"
                    },
                    {
                        "start": 606,
                        "end": 621,
                        "text": "(\u0160najder, 2016)",
                        "ref_id": null
                    }
                ],
                "ref_spans": [],
                "eq_spans": [],
                "section": "Introduction",
                "sec_num": "1"
            },
            {
                "text": "In this paper we focus on tweets, which are of great interest for the argument mining community due to the increasing use of the microblogging service Twitter 1 in political online discourse. While some first work on argument mining in tweets exists (Addawood and Bashir, 2016; Dusmanu et al., 2017) , only a small number of available annotated corpora have been created that can be utilized for training tweet-specific argument mining systems (Bosc et al., 2016) .",
                "cite_spans": [
                    {
                        "start": 250,
                        "end": 277,
                        "text": "(Addawood and Bashir, 2016;",
                        "ref_id": "BIBREF0"
                    },
                    {
                        "start": 278,
                        "end": 299,
                        "text": "Dusmanu et al., 2017)",
                        "ref_id": "BIBREF7"
                    },
                    {
                        "start": 444,
                        "end": 463,
                        "text": "(Bosc et al., 2016)",
                        "ref_id": "BIBREF4"
                    }
                ],
                "ref_spans": [],
                "eq_spans": [],
                "section": "Introduction",
                "sec_num": "1"
            },
            {
                "text": "To improve on this point, we present a new corpus of German tweets annotated for claim and evidence 2 . To the best of our knowledge, this is the first argument tweet corpus not exclusively annotated with the full tweet as the unit of annotation. Instead, argumentative spans within tweets, henceforth called argumentative discourse units (ADU) (Peldszus and Stede, 2013) , have been annotated as well. They render the corpus suitable not only for supervised classification but also for sequence labeling approaches. We also present first promising experimental results using this corpus.",
                "cite_spans": [
                    {
                        "start": 345,
                        "end": 371,
                        "text": "(Peldszus and Stede, 2013)",
                        "ref_id": "BIBREF16"
                    }
                ],
                "ref_spans": [],
                "eq_spans": [],
                "section": "Introduction",
                "sec_num": "1"
            },
            {
                "text": "This paper is structured as follows: Section 2 gives a short overview of the relevant social media and Twitter-related literature on argument mining. Section 3 describes the corpus, the annotation scheme and the annotation procedure. In Section 4 we present first classification and sequence labeling results using the annotated data. Section 5 discusses our results and gives a brief outlook. Addawood and Bashir (2016) present a corpus of English tweets annotated for arguments and evidence types like news media accounts or expert opinions. First, arguments are identified on the full tweet level, followed by the subsequent annotation of evidence types. Annotators achieved Cohen's Kappa scores of 0.67 and 0.79, respectively. An SVM trained on linguistic and Twitter-related features yielded an F1 score of 0.89 on the binary classification task (non-argumentative vs argumentative). Bosc et al. (2016) describe DART, a Twitter argument corpus annotated for arguments and their relations. In contrast to our work, they do not distinguish claim from evidence but join them in the category argumentative. Again, annotations are conducted on the full tweet level and result in a Krippendorff alpha score of 0.81. This corpus is used by Dusmanu et al. (2017) for argument classification. Using a set of lexical, Twitter-specific, semantic and sentiment features, they achieved an F1 score of 0.78 on the binary classification task (non-argumentative vs argumentative). They further investigated approaches to perform fact recognition and source identification. Wojatzki and Zesch (2016) propose an alternative approach to argument mining in tweets. Specifically, they reconsider the challenging problem of implicit claim detection as a stance classification problem by reformulating implicit claims as implicit stances. This procedure is based on the assumption that an implicit stance can be more easily inferred from the respective tweet. They present the Atheism Stance Corpus, which contains tweets annotated for implicit stances. An SVM trained on token and character n-grams yielded an F1 score of 0.66. Schaefer and Stede (2019) improve on these results using different word and sentence embeddings (F1: 0.78). Goudas et al. (2014) offer early results for argument mining not specifically on Twitter but on social media. They apply classification to separate non-argumentative from argumentative texts. In a subsequent step, sequence labeling is used to extract ADUs from the latter. This two-step approach makes their work comparable to ours. They report F1 scores of 0.77 and 0.42 for the two tasks, respectively.",
                "cite_spans": [
                    {
                        "start": 394,
                        "end": 420,
                        "text": "Addawood and Bashir (2016)",
                        "ref_id": "BIBREF0"
                    },
                    {
                        "start": 889,
                        "end": 907,
                        "text": "Bosc et al. (2016)",
                        "ref_id": "BIBREF4"
                    },
                    {
                        "start": 1238,
                        "end": 1259,
                        "text": "Dusmanu et al. (2017)",
                        "ref_id": "BIBREF7"
                    },
                    {
                        "start": 1562,
                        "end": 1587,
                        "text": "Wojatzki and Zesch (2016)",
                        "ref_id": "BIBREF20"
                    },
                    {
                        "start": 2219,
                        "end": 2239,
                        "text": "Goudas et al. (2014)",
                        "ref_id": "BIBREF10"
                    }
                ],
                "ref_spans": [],
                "eq_spans": [],
                "section": "Introduction",
                "sec_num": "1"
            },
            {
                "text": "Our complete initial corpus consists of 77,100 tweets collected in 2019 via the Twitter API using the Python library Tweepy 3 . All tweets contain the keyword klima (\"climate\") and mainly concentrate on the topic of climate change, which was intensely discussed by German media and politics during that time. We conducted the following preprocessing steps.",
                "cite_spans": [],
                "ref_spans": [],
                "eq_spans": [],
                "section": "Corpus Annotation",
                "sec_num": "3"
            },
            {
                "text": "First, we removed all retweets and excluded non-German tweets using the language identification tool langid (Lui and Baldwin, 2012) . These steps led to a subset of 29,525 tweets. In the following, we grouped the tweets into pairs, consisting of a tweet, henceforth called context tweet, and the tweet to be annotated, which is a reply to the context tweet and, for this reason, is called reply tweet. This approach is motivated by the assumption that tweets in a reply relation are more likely to contain argumentation (Dykes et al., 2020) . Moreover, given the short nature of tweets, providing a context is supposed to help interpreting the reply tweet's content. All tweets that were no replies were removed and missing context tweets were collected in an additional step. Finally, we removed all @-mentions at the beginning of a tweet, as these mainly point to the tweet's recipients. The final corpus consists of 12,296 context and reply tweet pairs. For the present study, a subset of 300 tweet pairs was annotated. 4",
                "cite_spans": [
                    {
                        "start": 108,
                        "end": 131,
                        "text": "(Lui and Baldwin, 2012)",
                        "ref_id": null
                    },
                    {
                        "start": 520,
                        "end": 540,
                        "text": "(Dykes et al., 2020)",
                        "ref_id": "BIBREF8"
                    }
                ],
                "ref_spans": [],
                "eq_spans": [],
                "section": "Corpus Annotation",
                "sec_num": "3"
            },
            {
                "text": "We focus on the two main components of argumentation: claim and evidence. We define a claim as a standpoint towards the topic being discussed (i.e. climate change). In contrast, an evidence unit is a statement used to support or attack such a standpoint. Hence, the crucial difference between claim and evidence is the characteristic of evidence units being always related to another statement while claims can be independent units. We distinguish further between evidence 1) relating to a claim in the reply tweet, 2) relating to a claim in the context tweet and 3) relating to claims in both tweets. Importantly, we do not define an ADU syntactically, e.g. by focusing exclusively on the clause or sentence level.",
                "cite_spans": [],
                "ref_spans": [],
                "eq_spans": [],
                "section": "Annotation Scheme",
                "sec_num": "3.1"
            },
            {
                "text": "Due to the informal language used in the tweets we consider it appropriate to allow the annotators some flexibility to decide on the actual ADU span.",
                "cite_spans": [],
                "ref_spans": [],
                "eq_spans": [],
                "section": "Annotation Scheme",
                "sec_num": "3.1"
            },
            {
                "text": "As distinguishing between claim and evidence can be a quite subjective task, especially on Twitter, annotators were advised to follow our component definitions as close as possible. Statements that function independently of other statements shall be annotated as claims. However, if a statement refers to another proposition either by supporting or attacking it or by giving additional information it shall be annotated as evidence, despite its potential usability as a claim. Therefore, annotators were further instructed to focus on possible causal relationships (in a wide sense) between two statements. If a statement directly follows from another it is likely to be a claim (e.g. [We have to limit CO2 emissions] claim , [as too much CO2 has been shown to increase the greenhouse effect.] evidence ). We found that using this strategy to decide on the direction of the argumentation, i.e. which ADU is evidence and which ADU is the claim, facilitated the annotation procedure notably. For our purposes, we do not differentiate between correct and incorrect statements. We also do not explicitly annotate relations between two components.",
                "cite_spans": [],
                "ref_spans": [],
                "eq_spans": [],
                "section": "Annotation Scheme",
                "sec_num": "3.1"
            },
            {
                "text": "Two annotators, one of which is a co-author of this paper, were trained in an iterative two-step procedure. First, both annotators individually labelled a subset of 20 tweet pairs according to the annotation scheme. They compared their results, discussed different interpretations and tried to consolidate them. This procedure was repeated until both annotators felt comfortable in completing the task.",
                "cite_spans": [],
                "ref_spans": [],
                "eq_spans": [],
                "section": "Annotation Procedure and Results",
                "sec_num": "3.2"
            },
            {
                "text": "For the actual annotation study we again used a two-step approach. Annotators first had to answer two multiple choice questions asking if a claim or evidence can be identified in the reply tweet. Only if one of the two components was found the annotator would continue to the ADU annotation step. No restrictions on the allowed maximal number of components per tweet were made, as this could potentially have led to differing choices in longer tweets. While annotations themselves only were created for ADU spans, we also derived separate tweet-level annotation sets for claim, evidence and argument (claim or evidence) annotations. Also, we experimented with analysing annotations both on the tweet and the ADU level.",
                "cite_spans": [],
                "ref_spans": [],
                "eq_spans": [],
                "section": "Annotation Procedure and Results",
                "sec_num": "3.2"
            },
            {
                "text": "First, we present mean percentages of the ADU annotation frequencies. Of the 300 tweets 14% were annotated as non-argumentative. 27% of the tweets contained exactly one ADU (25%: claim; 2%: evidence). 59% of the tweets were annotated for multiple ADUs (27%: 1 claim & 1 evidence unit; 2% 1 claim & >1 evidence units; 15%: >1 claims & 1 evidence unit) which demonstrates the need for ADU-level annotation even in short texts like tweets.",
                "cite_spans": [],
                "ref_spans": [],
                "eq_spans": [],
                "section": "Annotation Procedure and Results",
                "sec_num": "3.2"
            },
            {
                "text": "Claim Evidence Cohen's Kappa 0.55 0.37 We calculated Cohen's Kappa scores to measure Inter Annotator Agreement (IAA) (Artstein and Poesio, 2008) . As shown in Table 1 , results for the claim and evidence questions were 0.55 and 0.37, respectively, which indicates that deciding on the presence of evidence is more subjective. This pattern returns in the scores based on the annotations on the tweet level (Table 2) . Whereas results for argument and claim annotations are somewhat similar, the kappa for evidence annotation is reduced. Further, the results show that the multi class annotation (claim vs evidence vs non-argumentative) is particularly difficult. As this task is somewhat subjective in nature, a drop of performance is expected. Although we are aware that the IAA results are relatively low, we consider them acceptable due to the subtlety of the task. This is in line with the interpretation of annotation results by Aharoni et al. (2014) , who report 0.39 and 0.4 for claim and evidence annotation tasks, respectively.",
                "cite_spans": [
                    {
                        "start": 117,
                        "end": 144,
                        "text": "(Artstein and Poesio, 2008)",
                        "ref_id": "BIBREF3"
                    },
                    {
                        "start": 933,
                        "end": 954,
                        "text": "Aharoni et al. (2014)",
                        "ref_id": "BIBREF1"
                    }
                ],
                "ref_spans": [
                    {
                        "start": 159,
                        "end": 166,
                        "text": "Table 1",
                        "ref_id": "TABREF0"
                    },
                    {
                        "start": 405,
                        "end": 414,
                        "text": "(Table 2)",
                        "ref_id": "TABREF1"
                    }
                ],
                "eq_spans": [],
                "section": "Metric",
                "sec_num": null
            },
            {
                "text": "In this section, we present first experimental results based on the annotated corpus. We apply two different approaches: For the tweet-level annotations we trained supervised classification models. This is comparable to the prior studies of Addawood and Bashir (2016) and Dusmanu et al. (2017) . In addition, we use the ADU-level annotations for running a sequence labeling approach similar to Goudas et al. (2014) . We experimented with different combinations of feature sets, preprocessing steps and models. However, we only present the best results here. Table 3 : Classification Results (l = lowercase, p = punctuation, s = stopword, w = weighted)",
                "cite_spans": [
                    {
                        "start": 241,
                        "end": 267,
                        "text": "Addawood and Bashir (2016)",
                        "ref_id": "BIBREF0"
                    },
                    {
                        "start": 272,
                        "end": 293,
                        "text": "Dusmanu et al. (2017)",
                        "ref_id": "BIBREF7"
                    },
                    {
                        "start": 394,
                        "end": 414,
                        "text": "Goudas et al. (2014)",
                        "ref_id": "BIBREF10"
                    }
                ],
                "ref_spans": [
                    {
                        "start": 558,
                        "end": 565,
                        "text": "Table 3",
                        "ref_id": null
                    }
                ],
                "eq_spans": [],
                "section": "Experiments and Results",
                "sec_num": "4"
            },
            {
                "text": "Tweet level. Classification models were trained on different combinations of n-grams and on pretrained BERT-based document embeddings (Devlin et al., 2019) . The latter were created using FLAIR, an NLP framework that contains a unified interface for employing different types of text embeddings (Akbik et al., 2019) . All shown classification results are yielded using eXtreme Gradient Boosting (XGBoost) (Chen and Guestrin, 2016) , which is a variant of the Gradient Boosting approach introduced by Friedman (2000). We implemented three different classification tasks based on the respective binary target sets: argumentative vs non-argumentative, claim vs no claim or evidence vs no evidence. All results are 10-fold cross-validated. Table 3 shows macro F1, precision and recall scores, which are weighted for the unbalanced distribution of classes. Pretrained BERT embeddings yield better F1 scores for argument (0.82 vs 0.8) and claim (0.82 vs 0.79) classifications. Interestingly, a model trained on uni-and bigrams performs better on the evidence task than the BERT-based model (0.67 vs 0.59). Importantly, scores for the argument and claim tasks are substantially higher than for the evidence task. ADU level. Sequence labeling models were trained on the following features: 1) unigrams, 2) a combination of linguistic (e.g., n-grams, POS Tags) and Twitter-related (e.g., hashtags, @-mentions) features, 3) pretrained BERT-based word embeddings, which were again created using FLAIR. We chose a Conditional Random Fields approach (Lafferty et al., 2001 ), using the sklearn-crfsuite 5 . Again, all results are from 10-fold cross-validation. In the sequence labeling approach BERT-based models perform best for all three labeling tasks. Using a set of linguistic and Twitter-related features improves the F1 scores compared to the simple unigram models in the argument (0.7 vs 0.69) and claim (0.56 vs 0.53) tasks. However, no improvement is achieved in the evidence task. Interestingly, scores are highest for the evidence task whereas the results for the claim task are considerably lower. This pattern contrasts with the tweet-level classification results.",
                "cite_spans": [
                    {
                        "start": 134,
                        "end": 155,
                        "text": "(Devlin et al., 2019)",
                        "ref_id": "BIBREF6"
                    },
                    {
                        "start": 295,
                        "end": 315,
                        "text": "(Akbik et al., 2019)",
                        "ref_id": "BIBREF2"
                    },
                    {
                        "start": 405,
                        "end": 430,
                        "text": "(Chen and Guestrin, 2016)",
                        "ref_id": "BIBREF5"
                    },
                    {
                        "start": 1537,
                        "end": 1559,
                        "text": "(Lafferty et al., 2001",
                        "ref_id": "BIBREF12"
                    }
                ],
                "ref_spans": [
                    {
                        "start": 736,
                        "end": 743,
                        "text": "Table 3",
                        "ref_id": null
                    }
                ],
                "eq_spans": [],
                "section": "Features",
                "sec_num": null
            },
            {
                "text": "In this paper we presented a new corpus of German tweets annotated for claim and evidence. While a few previous studies on tweet corpus creation for argument mining exist (Bosc et al., 2016) , to the best of our knowledge our corpus is the first tweet dataset with ADU annotations. It is also the first German tweet dataset generally annotated for argumentation.",
                "cite_spans": [
                    {
                        "start": 171,
                        "end": 190,
                        "text": "(Bosc et al., 2016)",
                        "ref_id": "BIBREF4"
                    }
                ],
                "ref_spans": [],
                "eq_spans": [],
                "section": "Discussion and Outlook",
                "sec_num": "5"
            },
            {
                "text": "Although we showed that due to the subtlety of the task relatively low IAA scores were achieved, classification and sequence labeling results based on the dataset are promising. Classifying argument and claim components led to robust F1 scores around 0.8. Solely evidence units posed somewhat of a challenge for the classifier. However, sequence labeling models performed best for evidence units. With both approaches we surpassed the results presented by Goudas et al. (2014) .",
                "cite_spans": [
                    {
                        "start": 456,
                        "end": 476,
                        "text": "Goudas et al. (2014)",
                        "ref_id": "BIBREF10"
                    }
                ],
                "ref_spans": [],
                "eq_spans": [],
                "section": "Discussion and Outlook",
                "sec_num": "5"
            },
            {
                "text": "Given that the IAA scores for evidence annotations were reduced as well, we conclude that evidence units pose an especially hard problem to solve. Recalling our definitions of claim and evidence, this seems intuitive. As evidence units are only defined with respect to claims, a decision has to be made about the exact boundary between both components. Moreover, since tweets tend to contain a high degree of implicitness, it can be demanding to judge if a sequence in fact is relating to a claim. We plan to take this issue into account by refining our annotation scheme further.",
                "cite_spans": [],
                "ref_spans": [],
                "eq_spans": [],
                "section": "Discussion and Outlook",
                "sec_num": "5"
            },
            {
                "text": "Another interesting path of future work will be the continuing development of the argument detector. Following Goudas et al. (2014) , one possible way of enhancing results could be building a pipeline based on both classification and sequence labeling approaches. More specifically, a classifier customized for identifying argumentative tweets could function as a filter, thereby allowing to train a sequence labeling model on a purely argumentative tweet set. This could increase the model's precision. To this end, we intend to enlarge the number of annotated data.",
                "cite_spans": [
                    {
                        "start": 111,
                        "end": 131,
                        "text": "Goudas et al. (2014)",
                        "ref_id": "BIBREF10"
                    }
                ],
                "ref_spans": [],
                "eq_spans": [],
                "section": "Discussion and Outlook",
                "sec_num": "5"
            },
            {
                "text": "https://www.tweepy.org/ 4 Corpus repository: https://github.com/RobinSchaefer/climate-tweet-corpus.",
                "cite_spans": [],
                "ref_spans": [],
                "eq_spans": [],
                "section": "",
                "sec_num": null
            },
            {
                "text": "sklearn-crfsuite (https://sklearn-crfsuite.readthedocs.io) is a scikit-learn wrapper based on CRFsuite (http://www.chokkan.org/software/crfsuite/).",
                "cite_spans": [],
                "ref_spans": [],
                "eq_spans": [],
                "section": "",
                "sec_num": null
            }
        ],
        "back_matter": [
            {
                "text": "We would like to thank Polina Krasilnikova for assisting in annotating our data and Crowdee (https: //www.crowdee.com/) for support with their annotation environment. We further thank the anonymous reviewers for their helpful comments.",
                "cite_spans": [],
                "ref_spans": [],
                "eq_spans": [],
                "section": "Acknowledgements",
                "sec_num": null
            }
        ],
        "bib_entries": {
            "BIBREF0": {
                "ref_id": "b0",
                "title": "what is your evidence?\" a study of controversial topics on social media",
                "authors": [
                    {
                        "first": "Aseel",
                        "middle": [],
                        "last": "Addawood",
                        "suffix": ""
                    },
                    {
                        "first": "Masooda",
                        "middle": [],
                        "last": "Bashir",
                        "suffix": ""
                    }
                ],
                "year": 2016,
                "venue": "Proceedings of the Third Workshop on Argument Mining (ArgMining2016)",
                "volume": "",
                "issue": "",
                "pages": "1--11",
                "other_ids": {},
                "num": null,
                "urls": [],
                "raw_text": "Aseel Addawood and Masooda Bashir. 2016. \"what is your evidence?\" a study of controversial topics on social media. In Proceedings of the Third Workshop on Argument Mining (ArgMining2016), pages 1-11, Berlin, Germany, August. Association for Computational Linguistics.",
                "links": null
            },
            "BIBREF1": {
                "ref_id": "b1",
                "title": "A benchmark dataset for automatic detection of claims and evidence in the context of controversial topics",
                "authors": [
                    {
                        "first": "Ehud",
                        "middle": [],
                        "last": "Aharoni",
                        "suffix": ""
                    },
                    {
                        "first": "Anatoly",
                        "middle": [],
                        "last": "Polnarov",
                        "suffix": ""
                    },
                    {
                        "first": "Tamar",
                        "middle": [],
                        "last": "Lavee",
                        "suffix": ""
                    },
                    {
                        "first": "Daniel",
                        "middle": [],
                        "last": "Hershcovich",
                        "suffix": ""
                    },
                    {
                        "first": "Ran",
                        "middle": [],
                        "last": "Levy",
                        "suffix": ""
                    },
                    {
                        "first": "Ruty",
                        "middle": [],
                        "last": "Rinott",
                        "suffix": ""
                    },
                    {
                        "first": "Dan",
                        "middle": [],
                        "last": "Gutfreund",
                        "suffix": ""
                    },
                    {
                        "first": "Noam",
                        "middle": [],
                        "last": "Slonim",
                        "suffix": ""
                    }
                ],
                "year": 2014,
                "venue": "Proceedings of the First Workshop on Argumentation Mining",
                "volume": "",
                "issue": "",
                "pages": "64--68",
                "other_ids": {},
                "num": null,
                "urls": [],
                "raw_text": "Ehud Aharoni, Anatoly Polnarov, Tamar Lavee, Daniel Hershcovich, Ran Levy, Ruty Rinott, Dan Gutfreund, and Noam Slonim. 2014. A benchmark dataset for automatic detection of claims and evidence in the context of controversial topics. In Proceedings of the First Workshop on Argumentation Mining, pages 64-68, Baltimore, Maryland, June. Association for Computational Linguistics.",
                "links": null
            },
            "BIBREF2": {
                "ref_id": "b2",
                "title": "FLAIR: An easy-to-use framework for state-of-the-art NLP",
                "authors": [
                    {
                        "first": "Alan",
                        "middle": [],
                        "last": "Akbik",
                        "suffix": ""
                    },
                    {
                        "first": "Tanja",
                        "middle": [],
                        "last": "Bergmann",
                        "suffix": ""
                    },
                    {
                        "first": "Duncan",
                        "middle": [],
                        "last": "Blythe",
                        "suffix": ""
                    },
                    {
                        "first": "Kashif",
                        "middle": [],
                        "last": "Rasul",
                        "suffix": ""
                    },
                    {
                        "first": "Stefan",
                        "middle": [],
                        "last": "Schweter",
                        "suffix": ""
                    },
                    {
                        "first": "Roland",
                        "middle": [],
                        "last": "Vollgraf",
                        "suffix": ""
                    }
                ],
                "year": 2019,
                "venue": "Proceedings of the 2019 Conference of the North American Chapter of the Association for Computational Linguistics (Demonstrations)",
                "volume": "",
                "issue": "",
                "pages": "54--59",
                "other_ids": {},
                "num": null,
                "urls": [],
                "raw_text": "Alan Akbik, Tanja Bergmann, Duncan Blythe, Kashif Rasul, Stefan Schweter, and Roland Vollgraf. 2019. FLAIR: An easy-to-use framework for state-of-the-art NLP. In Proceedings of the 2019 Conference of the North Amer- ican Chapter of the Association for Computational Linguistics (Demonstrations), pages 54-59, Minneapolis, Minnesota, June. Association for Computational Linguistics.",
                "links": null
            },
            "BIBREF3": {
                "ref_id": "b3",
                "title": "Inter-coder agreement for computational linguistics",
                "authors": [
                    {
                        "first": "Ron",
                        "middle": [],
                        "last": "Artstein",
                        "suffix": ""
                    },
                    {
                        "first": "Massimo",
                        "middle": [],
                        "last": "Poesio",
                        "suffix": ""
                    }
                ],
                "year": 2008,
                "venue": "Comput. Linguist",
                "volume": "34",
                "issue": "4",
                "pages": "555--596",
                "other_ids": {},
                "num": null,
                "urls": [],
                "raw_text": "Ron Artstein and Massimo Poesio. 2008. Inter-coder agreement for computational linguistics. Comput. Linguist., 34(4):555-596, December.",
                "links": null
            },
            "BIBREF4": {
                "ref_id": "b4",
                "title": "DART: a dataset of arguments and their relations on twitter",
                "authors": [
                    {
                        "first": "Tom",
                        "middle": [],
                        "last": "Bosc",
                        "suffix": ""
                    },
                    {
                        "first": "Elena",
                        "middle": [],
                        "last": "Cabrio",
                        "suffix": ""
                    },
                    {
                        "first": "Serena",
                        "middle": [],
                        "last": "Villata",
                        "suffix": ""
                    }
                ],
                "year": 2016,
                "venue": "Proceedings of the Tenth International Conference on Language Resources and Evaluation (LREC'16)",
                "volume": "",
                "issue": "",
                "pages": "1258--1263",
                "other_ids": {},
                "num": null,
                "urls": [],
                "raw_text": "Tom Bosc, Elena Cabrio, and Serena Villata. 2016. DART: a dataset of arguments and their relations on twitter. In Proceedings of the Tenth International Conference on Language Resources and Evaluation (LREC'16), pages 1258-1263, Portoro\u017e, Slovenia, May. European Language Resources Association (ELRA).",
                "links": null
            },
            "BIBREF5": {
                "ref_id": "b5",
                "title": "XGBoost: A scalable tree boosting system",
                "authors": [
                    {
                        "first": "Tianqi",
                        "middle": [],
                        "last": "Chen",
                        "suffix": ""
                    },
                    {
                        "first": "Carlos",
                        "middle": [],
                        "last": "Guestrin",
                        "suffix": ""
                    }
                ],
                "year": 2016,
                "venue": "Proceedings of the 22nd ACM SIGKDD International Conference on Knowledge Discovery and Data Mining, KDD '16",
                "volume": "",
                "issue": "",
                "pages": "785--794",
                "other_ids": {},
                "num": null,
                "urls": [],
                "raw_text": "Tianqi Chen and Carlos Guestrin. 2016. XGBoost: A scalable tree boosting system. In Proceedings of the 22nd ACM SIGKDD International Conference on Knowledge Discovery and Data Mining, KDD '16, pages 785-794, New York, NY, USA. Association for Computing Machinery.",
                "links": null
            },
            "BIBREF6": {
                "ref_id": "b6",
                "title": "BERT: Pre-training of deep bidirectional transformers for language understanding",
                "authors": [
                    {
                        "first": "Jacob",
                        "middle": [],
                        "last": "Devlin",
                        "suffix": ""
                    },
                    {
                        "first": "Ming-Wei",
                        "middle": [],
                        "last": "Chang",
                        "suffix": ""
                    },
                    {
                        "first": "Kenton",
                        "middle": [],
                        "last": "Lee",
                        "suffix": ""
                    },
                    {
                        "first": "Kristina",
                        "middle": [],
                        "last": "Toutanova",
                        "suffix": ""
                    }
                ],
                "year": 2019,
                "venue": "Proceedings of the 2019 Conference of the North American Chapter of the Association for Computational Linguistics: Human Language Technologies",
                "volume": "1",
                "issue": "",
                "pages": "4171--4186",
                "other_ids": {},
                "num": null,
                "urls": [],
                "raw_text": "Jacob Devlin, Ming-Wei Chang, Kenton Lee, and Kristina Toutanova. 2019. BERT: Pre-training of deep bidirec- tional transformers for language understanding. In Proceedings of the 2019 Conference of the North American Chapter of the Association for Computational Linguistics: Human Language Technologies, Volume 1 (Long and Short Papers), pages 4171-4186, Minneapolis, Minnesota, June. Association for Computational Linguistics.",
                "links": null
            },
            "BIBREF7": {
                "ref_id": "b7",
                "title": "Argument mining on twitter: Arguments, facts and sources",
                "authors": [
                    {
                        "first": "Mihai",
                        "middle": [],
                        "last": "Dusmanu",
                        "suffix": ""
                    },
                    {
                        "first": "Elena",
                        "middle": [],
                        "last": "Cabrio",
                        "suffix": ""
                    },
                    {
                        "first": "Serena",
                        "middle": [],
                        "last": "Villata",
                        "suffix": ""
                    }
                ],
                "year": 2017,
                "venue": "Proceedings of the 2017 Conference on Empirical Methods in Natural Language Processing",
                "volume": "",
                "issue": "",
                "pages": "2317--2322",
                "other_ids": {},
                "num": null,
                "urls": [],
                "raw_text": "Mihai Dusmanu, Elena Cabrio, and Serena Villata. 2017. Argument mining on twitter: Arguments, facts and sources. In Proceedings of the 2017 Conference on Empirical Methods in Natural Language Processing, pages 2317-2322, Copenhagen, Denmark, September. Association for Computational Linguistics.",
                "links": null
            },
            "BIBREF8": {
                "ref_id": "b8",
                "title": "Reconstructing arguments from noisy text",
                "authors": [
                    {
                        "first": "Natalie",
                        "middle": [],
                        "last": "Dykes",
                        "suffix": ""
                    },
                    {
                        "first": "Stefan",
                        "middle": [],
                        "last": "Evert",
                        "suffix": ""
                    },
                    {
                        "first": "Merlin",
                        "middle": [],
                        "last": "G\u00f6ttlinger",
                        "suffix": ""
                    },
                    {
                        "first": "Philipp",
                        "middle": [],
                        "last": "Heinrich",
                        "suffix": ""
                    },
                    {
                        "first": "Lutz",
                        "middle": [],
                        "last": "Schr\u00f6der",
                        "suffix": ""
                    }
                ],
                "year": 2020,
                "venue": "Datenbank-Spektrum",
                "volume": "20",
                "issue": "2",
                "pages": "123--129",
                "other_ids": {},
                "num": null,
                "urls": [],
                "raw_text": "Natalie Dykes, Stefan Evert, Merlin G\u00f6ttlinger, Philipp Heinrich, and Lutz Schr\u00f6der. 2020. Reconstructing arguments from noisy text. Datenbank-Spektrum, 20(2):123-129.",
                "links": null
            },
            "BIBREF9": {
                "ref_id": "b9",
                "title": "Greedy function approximation: A gradient boosting machine",
                "authors": [
                    {
                        "first": "H",
                        "middle": [],
                        "last": "Jerome",
                        "suffix": ""
                    },
                    {
                        "first": "",
                        "middle": [],
                        "last": "Friedman",
                        "suffix": ""
                    }
                ],
                "year": 2000,
                "venue": "Annals of Statistics",
                "volume": "29",
                "issue": "",
                "pages": "1189--1232",
                "other_ids": {},
                "num": null,
                "urls": [],
                "raw_text": "Jerome H. Friedman. 2000. Greedy function approximation: A gradient boosting machine. Annals of Statistics, 29:1189-1232.",
                "links": null
            },
            "BIBREF10": {
                "ref_id": "b10",
                "title": "Argument extraction from news, blogs, and social media",
                "authors": [
                    {
                        "first": "Theodosis",
                        "middle": [],
                        "last": "Goudas",
                        "suffix": ""
                    },
                    {
                        "first": "Christos",
                        "middle": [],
                        "last": "Louizos",
                        "suffix": ""
                    }
                ],
                "year": 2014,
                "venue": "Aristidis Likas, Konstantinos Blekas, and Dimitris Kalles",
                "volume": "",
                "issue": "",
                "pages": "287--299",
                "other_ids": {},
                "num": null,
                "urls": [],
                "raw_text": "Theodosis Goudas, Christos Louizos, Georgios Petasis, and Vangelis Karkaletsis. 2014. Argument extraction from news, blogs, and social media. In Aristidis Likas, Konstantinos Blekas, and Dimitris Kalles, editors, Artificial Intelligence: Methods and Applications, pages 287-299, Cham. Springer International Publishing.",
                "links": null
            },
            "BIBREF11": {
                "ref_id": "b11",
                "title": "Exploiting debate portals for semi-supervised argumentation mining in user-generated web discourse",
                "authors": [
                    {
                        "first": "Ivan",
                        "middle": [],
                        "last": "Habernal",
                        "suffix": ""
                    },
                    {
                        "first": "Iryna",
                        "middle": [],
                        "last": "Gurevych",
                        "suffix": ""
                    }
                ],
                "year": 2015,
                "venue": "Proceedings of the 2015 Conference on Empirical Methods in Natural Language Processing",
                "volume": "",
                "issue": "",
                "pages": "2127--2137",
                "other_ids": {},
                "num": null,
                "urls": [],
                "raw_text": "Ivan Habernal and Iryna Gurevych. 2015. Exploiting debate portals for semi-supervised argumentation mining in user-generated web discourse. In Proceedings of the 2015 Conference on Empirical Methods in Natural Lan- guage Processing, pages 2127-2137, Lisbon, Portugal, September. Association for Computational Linguistics.",
                "links": null
            },
            "BIBREF12": {
                "ref_id": "b12",
                "title": "Conditional random fields: Probabilistic models for segmenting and labeling sequence data",
                "authors": [
                    {
                        "first": "John",
                        "middle": [
                            "D"
                        ],
                        "last": "Lafferty",
                        "suffix": ""
                    },
                    {
                        "first": "Andrew",
                        "middle": [],
                        "last": "Mccallum",
                        "suffix": ""
                    },
                    {
                        "first": "Fernando",
                        "middle": [
                            "C N"
                        ],
                        "last": "Pereira",
                        "suffix": ""
                    }
                ],
                "year": 2001,
                "venue": "Proceedings of the Eighteenth International Conference on Machine Learning, ICML '01",
                "volume": "",
                "issue": "",
                "pages": "282--289",
                "other_ids": {},
                "num": null,
                "urls": [],
                "raw_text": "John D. Lafferty, Andrew McCallum, and Fernando C. N. Pereira. 2001. Conditional random fields: Probabilistic models for segmenting and labeling sequence data. In Proceedings of the Eighteenth International Conference on Machine Learning, ICML '01, page 282-289, San Francisco, CA, USA. Morgan Kaufmann Publishers Inc.",
                "links": null
            },
            "BIBREF13": {
                "ref_id": "b13",
                "title": "2012. langid.py: An off-the-shelf language identification tool",
                "authors": [
                    {
                        "first": "Marco",
                        "middle": [],
                        "last": "Lui",
                        "suffix": ""
                    },
                    {
                        "first": "Timothy",
                        "middle": [],
                        "last": "Baldwin",
                        "suffix": ""
                    }
                ],
                "year": null,
                "venue": "Proceedings of the ACL 2012 System Demonstrations",
                "volume": "",
                "issue": "",
                "pages": "25--30",
                "other_ids": {},
                "num": null,
                "urls": [],
                "raw_text": "Marco Lui and Timothy Baldwin. 2012. langid.py: An off-the-shelf language identification tool. In Proceedings of the ACL 2012 System Demonstrations, pages 25-30, Jeju Island, Korea, July. Association for Computational Linguistics.",
                "links": null
            },
            "BIBREF14": {
                "ref_id": "b14",
                "title": "Automatic detection of arguments in legal texts",
                "authors": [
                    {
                        "first": "Marie-Francine",
                        "middle": [],
                        "last": "Moens",
                        "suffix": ""
                    },
                    {
                        "first": "Erik",
                        "middle": [],
                        "last": "Boiy",
                        "suffix": ""
                    }
                ],
                "year": 2007,
                "venue": "Proceedings of the 11th International Conference on Artificial Intelligence and Law, ICAIL '07",
                "volume": "",
                "issue": "",
                "pages": "225--230",
                "other_ids": {},
                "num": null,
                "urls": [],
                "raw_text": "Marie-Francine Moens, Erik Boiy, Raquel Mochales Palau, and Chris Reed. 2007. Automatic detection of argu- ments in legal texts. In Proceedings of the 11th International Conference on Artificial Intelligence and Law, ICAIL '07, page 225-230, New York, NY, USA. Association for Computing Machinery.",
                "links": null
            },
            "BIBREF15": {
                "ref_id": "b15",
                "title": "Identifying appropriate support for propositions in online user comments",
                "authors": [
                    {
                        "first": "Joonsuk",
                        "middle": [],
                        "last": "Park",
                        "suffix": ""
                    },
                    {
                        "first": "Claire",
                        "middle": [],
                        "last": "Cardie",
                        "suffix": ""
                    }
                ],
                "year": 2014,
                "venue": "Proceedings of the First Workshop on Argumentation Mining",
                "volume": "",
                "issue": "",
                "pages": "29--38",
                "other_ids": {},
                "num": null,
                "urls": [],
                "raw_text": "Joonsuk Park and Claire Cardie. 2014. Identifying appropriate support for propositions in online user comments. In Proceedings of the First Workshop on Argumentation Mining, pages 29-38, Baltimore, Maryland, June. Association for Computational Linguistics.",
                "links": null
            },
            "BIBREF16": {
                "ref_id": "b16",
                "title": "From argument diagrams to argumentation mining in texts: A survey",
                "authors": [
                    {
                        "first": "Andreas",
                        "middle": [],
                        "last": "Peldszus",
                        "suffix": ""
                    },
                    {
                        "first": "Manfred",
                        "middle": [],
                        "last": "Stede",
                        "suffix": ""
                    }
                ],
                "year": 2013,
                "venue": "Int. J. Cogn. Inform. Nat. Intell",
                "volume": "7",
                "issue": "1",
                "pages": "1--31",
                "other_ids": {},
                "num": null,
                "urls": [],
                "raw_text": "Andreas Peldszus and Manfred Stede. 2013. From argument diagrams to argumentation mining in texts: A survey. Int. J. Cogn. Inform. Nat. Intell., 7(1):1-31, January.",
                "links": null
            },
            "BIBREF17": {
                "ref_id": "b17",
                "title": "Improving implicit stance classification in tweets using word and sentence embeddings",
                "authors": [
                    {
                        "first": "Robin",
                        "middle": [],
                        "last": "Schaefer",
                        "suffix": ""
                    },
                    {
                        "first": "Manfred",
                        "middle": [],
                        "last": "Stede",
                        "suffix": ""
                    }
                ],
                "year": 2019,
                "venue": "KI 2019: Advances in Artificial Intelligence",
                "volume": "",
                "issue": "",
                "pages": "299--307",
                "other_ids": {},
                "num": null,
                "urls": [],
                "raw_text": "Robin Schaefer and Manfred Stede. 2019. Improving implicit stance classification in tweets using word and sentence embeddings. In Christoph Benzm\u00fcller and Heiner Stuckenschmidt, editors, KI 2019: Advances in Artificial Intelligence, pages 299-307, Cham. Springer International Publishing.",
                "links": null
            },
            "BIBREF18": {
                "ref_id": "b18",
                "title": "Identifying argumentative discourse structures in persuasive essays",
                "authors": [
                    {
                        "first": "Christian",
                        "middle": [],
                        "last": "Stab",
                        "suffix": ""
                    },
                    {
                        "first": "Iryna",
                        "middle": [],
                        "last": "Gurevych",
                        "suffix": ""
                    }
                ],
                "year": 2014,
                "venue": "Proceedings of the 2014 Conference on Empirical Methods in Natural Language Processing (EMNLP)",
                "volume": "",
                "issue": "",
                "pages": "46--56",
                "other_ids": {},
                "num": null,
                "urls": [],
                "raw_text": "Christian Stab and Iryna Gurevych. 2014. Identifying argumentative discourse structures in persuasive essays. In Proceedings of the 2014 Conference on Empirical Methods in Natural Language Processing (EMNLP), pages 46-56, Doha, Qatar, October. Association for Computational Linguistics.",
                "links": null
            },
            "BIBREF20": {
                "ref_id": "b20",
                "title": "Stance-based Argument Mining -Modeling Implicit Argumentation Using Stance",
                "authors": [
                    {
                        "first": "Michael",
                        "middle": [],
                        "last": "Wojatzki",
                        "suffix": ""
                    },
                    {
                        "first": "Torsten",
                        "middle": [],
                        "last": "Zesch",
                        "suffix": ""
                    }
                ],
                "year": 2016,
                "venue": "Proceedings of the KONVENS",
                "volume": "",
                "issue": "",
                "pages": "313--322",
                "other_ids": {},
                "num": null,
                "urls": [],
                "raw_text": "Michael Wojatzki and Torsten Zesch. 2016. Stance-based Argument Mining -Modeling Implicit Argumentation Using Stance. In Proceedings of the KONVENS, pages 313-322.",
                "links": null
            },
            "BIBREF21": {
                "ref_id": "b21",
                "title": "Social media argumentation mining: The quest for deliberateness in raucousness",
                "authors": [
                    {
                        "first": "",
                        "middle": [],
                        "last": "Jan\u0161najder",
                        "suffix": ""
                    }
                ],
                "year": 2016,
                "venue": "",
                "volume": "",
                "issue": "",
                "pages": "",
                "other_ids": {},
                "num": null,
                "urls": [],
                "raw_text": "Jan\u0160najder. 2016. Social media argumentation mining: The quest for deliberateness in raucousness.",
                "links": null
            }
        },
        "ref_entries": {
            "TABREF0": {
                "content": "<table><tr><td>Metric</td><td colspan=\"5\">Multi (s) Argumentative (s) Argumentative (t) Claim (t) Evidence (t)</td></tr><tr><td>Cohen's Kappa</td><td>0.38</td><td>0.45</td><td>0.53</td><td>0.55</td><td>0.44</td></tr></table>",
                "html": null,
                "type_str": "table",
                "num": null,
                "text": "Inter Annotator Agreement (Questions)"
            },
            "TABREF1": {
                "content": "<table/>",
                "html": null,
                "type_str": "table",
                "num": null,
                "text": "Inter Annotator Agreement (s = ADU span, t = full tweet)"
            },
            "TABREF4": {
                "content": "<table/>",
                "html": null,
                "type_str": "table",
                "num": null,
                "text": "Sequence Labeling Results (w = weighted)"
            }
        }
    }
}