File size: 100,223 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
1489
1490
1491
1492
1493
1494
1495
1496
1497
1498
1499
1500
1501
1502
1503
1504
1505
1506
1507
1508
1509
1510
1511
1512
1513
1514
1515
1516
1517
1518
1519
1520
1521
1522
1523
1524
1525
1526
1527
1528
1529
1530
1531
1532
1533
1534
1535
1536
1537
1538
1539
1540
1541
1542
1543
1544
1545
1546
1547
1548
1549
1550
1551
1552
1553
1554
1555
1556
1557
1558
1559
1560
1561
1562
1563
1564
1565
1566
1567
1568
1569
1570
1571
1572
1573
1574
1575
1576
1577
1578
1579
1580
1581
1582
1583
1584
1585
1586
1587
1588
1589
1590
1591
1592
1593
1594
1595
1596
1597
1598
1599
1600
1601
1602
1603
1604
1605
1606
1607
1608
1609
1610
1611
1612
1613
1614
1615
1616
1617
1618
1619
1620
1621
1622
1623
1624
1625
1626
1627
1628
1629
1630
1631
1632
1633
1634
1635
1636
1637
1638
1639
1640
1641
1642
1643
1644
1645
1646
1647
1648
1649
1650
1651
1652
1653
1654
1655
1656
1657
1658
1659
1660
1661
1662
1663
1664
1665
1666
1667
1668
1669
1670
1671
1672
1673
1674
1675
1676
1677
1678
1679
1680
1681
1682
1683
1684
1685
1686
1687
1688
1689
1690
1691
1692
1693
1694
1695
1696
1697
1698
1699
1700
1701
1702
1703
1704
1705
1706
1707
1708
1709
1710
1711
1712
1713
1714
1715
1716
1717
1718
1719
1720
1721
1722
1723
1724
1725
1726
1727
1728
1729
1730
1731
1732
1733
1734
1735
1736
1737
1738
1739
1740
1741
1742
1743
1744
1745
1746
1747
1748
1749
1750
1751
1752
1753
1754
1755
1756
1757
1758
1759
1760
1761
1762
1763
1764
1765
1766
1767
1768
1769
1770
1771
1772
1773
1774
1775
1776
1777
1778
1779
1780
1781
1782
1783
1784
1785
1786
1787
1788
1789
1790
1791
1792
1793
1794
1795
1796
1797
1798
1799
1800
1801
1802
1803
1804
1805
1806
1807
1808
1809
1810
1811
1812
1813
1814
1815
1816
1817
1818
1819
1820
1821
1822
1823
1824
1825
1826
1827
1828
1829
1830
1831
1832
1833
1834
1835
1836
1837
1838
1839
1840
1841
1842
1843
1844
1845
1846
1847
1848
1849
1850
1851
1852
1853
1854
1855
1856
1857
1858
1859
1860
1861
1862
1863
1864
1865
1866
1867
1868
1869
1870
1871
1872
1873
1874
1875
1876
1877
1878
1879
1880
1881
1882
1883
1884
1885
1886
1887
1888
1889
1890
1891
1892
1893
1894
1895
1896
1897
1898
1899
1900
1901
1902
1903
1904
1905
1906
1907
1908
1909
1910
1911
1912
1913
1914
1915
1916
1917
1918
1919
1920
1921
1922
1923
1924
1925
1926
1927
1928
1929
1930
1931
1932
1933
1934
1935
1936
1937
1938
1939
1940
1941
1942
1943
1944
1945
1946
1947
1948
1949
1950
1951
1952
1953
1954
1955
1956
1957
1958
1959
1960
1961
1962
1963
1964
1965
1966
{
    "paper_id": "I11-1020",
    "header": {
        "generated_with": "S2ORC 1.0.0",
        "date_generated": "2023-01-19T07:31:20.497656Z"
    },
    "title": "Improving Related Entity Finding via Incorporating Homepages and Recognizing Fine-grained Entities",
    "authors": [
        {
            "first": "Youzheng",
            "middle": [],
            "last": "Wu",
            "suffix": "",
            "affiliation": {},
            "email": "youzheng.wu@nict.go.jp"
        },
        {
            "first": "Chiori",
            "middle": [],
            "last": "Hori",
            "suffix": "",
            "affiliation": {},
            "email": "chiori.hori@nict.go.jp"
        },
        {
            "first": "Hisashi",
            "middle": [],
            "last": "Kawai",
            "suffix": "",
            "affiliation": {},
            "email": "hisashi.kawai@nict.go.jp"
        },
        {
            "first": "Hideki",
            "middle": [],
            "last": "Kashioka",
            "suffix": "",
            "affiliation": {},
            "email": "hideki.kashioka@nict.go.jp"
        }
    ],
    "year": "",
    "venue": null,
    "identifiers": {},
    "abstract": "This paper describes experiments on the TREC entity track that studies retrieval of homepages representing entities relevant to a query. Many studies have focused on extracting entities that match the given coarse-grained types such as organizations, persons, locations by using a named entity recognizer, and employing language model techniques to calculate similarities between query and supporting snippets of entities from which entities are extracted to rank the entities. This paper proposes three improvements over baseline, i.e., 1) incorporating homepages of entities to supplement supporting snippets, 2) recognizing fine-grained named entities to filter out or negatively reward extracted entities that do not match the specified fine-grained types of entities such as a university, airline, author, and 3) adopting a dependency tree-based similarity method to improve language model techniques. Our experiments demonstrate that the proposed approaches can significantly improve performance, for instance, the absolute improvements of nDCG@R and P@1 scores are 8.4%, and 27.5%.",
    "pdf_parse": {
        "paper_id": "I11-1020",
        "_pdf_hash": "",
        "abstract": [
            {
                "text": "This paper describes experiments on the TREC entity track that studies retrieval of homepages representing entities relevant to a query. Many studies have focused on extracting entities that match the given coarse-grained types such as organizations, persons, locations by using a named entity recognizer, and employing language model techniques to calculate similarities between query and supporting snippets of entities from which entities are extracted to rank the entities. This paper proposes three improvements over baseline, i.e., 1) incorporating homepages of entities to supplement supporting snippets, 2) recognizing fine-grained named entities to filter out or negatively reward extracted entities that do not match the specified fine-grained types of entities such as a university, airline, author, and 3) adopting a dependency tree-based similarity method to improve language model techniques. Our experiments demonstrate that the proposed approaches can significantly improve performance, for instance, the absolute improvements of nDCG@R and P@1 scores are 8.4%, and 27.5%.",
                "cite_spans": [],
                "ref_spans": [],
                "eq_spans": [],
                "section": "Abstract",
                "sec_num": null
            }
        ],
        "body_text": [
            {
                "text": "Many user information needs would be better answered by presenting a ranked list of entities directly, instead of just a list of relevant documents. Based on this assumption, increasing attention has been devoted to related entity finding tasks that aimed at finding documents representing entities of a correct type that are relevant to a query. The TREC expert finding track (Nick, 2005) , for example, focused on creating an ordered list of experts who have skills and experiments on a given topic. The INEX entity ranking task (Vries, 2007) studied at ranking Wikipedia entities given a query, in which target entity types are shifted from a single type of entity (person) to any Wikipedia category. The TREC related entity finding (REF) track (Balog, 2010) started in 2009, is defined as: Given an input entity, by its name and homepage, the type of the target entity 1 , as well as the nature of their relation, described in free text, find related entities that are of a target type, standing in the required relation to the input entity. The REF task is also similar to a combination of the TREC list QA (Voorhees, 2003) and homepage finding (Hawking, 2001 ) tasks. In short, all these entity finding tasks generally aim at performing entity-oriented search tasks on the Web. This paper is concerned with the TREC REF track. Figure 1 shows an example of this. <query> <num>7</num> <entity_name>Boeing 747</entity_name> <entity_URL>clueweb09-en0005-75-02292</entity_URL> <target_entity>organization</target_entity> <narrative>Airlines that currently use Boeing 747 planes.</narrative> </query> The key challenge in the REF task involves entity ranking, that is, estimating the likelihood of the extracted entities being answer entities for a given query. Many related studies ) have employed language model techniques to estimate the likelihoods of the extracted entities being answer entities via calculating similarities between query and supporting documents/snippets of entities. This technique may fail in cases where supporting documents/snippets of entities do not support their being answer entities.",
                "cite_spans": [
                    {
                        "start": 377,
                        "end": 389,
                        "text": "(Nick, 2005)",
                        "ref_id": "BIBREF23"
                    },
                    {
                        "start": 531,
                        "end": 544,
                        "text": "(Vries, 2007)",
                        "ref_id": null
                    },
                    {
                        "start": 1112,
                        "end": 1128,
                        "text": "(Voorhees, 2003)",
                        "ref_id": "BIBREF9"
                    },
                    {
                        "start": 1150,
                        "end": 1164,
                        "text": "(Hawking, 2001",
                        "ref_id": "BIBREF6"
                    }
                ],
                "ref_spans": [
                    {
                        "start": 1333,
                        "end": 1341,
                        "text": "Figure 1",
                        "ref_id": "FIGREF0"
                    }
                ],
                "eq_spans": [],
                "section": "Introduction",
                "sec_num": "1"
            },
            {
                "text": "To improve the above approach, this paper first argues that candidate entities' homepages are important supplements to supporting snippets and should be effectively exploited. Homepage information is, however, ignored by many TREC participants' systems. Second, much of the work to date only extracts coarse-grained types of entities (such as people, organizations, locations and products specified in target entity field as shown in Figure 1 ) by using entity repositories such as YAGO (Suchanek, 2007) or named entity recognizers (Ratinov, 2009) , and then rank them. However, some queries specify fine-grained types of target entities in narrative fields, such as airlines in Figure 1 . In these cases, fine-grained entity recognition is necessary and helpful for improving performance, which can recognize fine-grained named entities such as airlines, publishers, drivers, or newspapers. Third, a dependency tree-based similarity approach is implemented to substitute language model techniques, which proved superior to the latter.",
                "cite_spans": [
                    {
                        "start": 487,
                        "end": 503,
                        "text": "(Suchanek, 2007)",
                        "ref_id": "BIBREF10"
                    },
                    {
                        "start": 532,
                        "end": 547,
                        "text": "(Ratinov, 2009)",
                        "ref_id": "BIBREF18"
                    }
                ],
                "ref_spans": [
                    {
                        "start": 434,
                        "end": 442,
                        "text": "Figure 1",
                        "ref_id": "FIGREF0"
                    },
                    {
                        "start": 679,
                        "end": 687,
                        "text": "Figure 1",
                        "ref_id": "FIGREF0"
                    }
                ],
                "eq_spans": [],
                "section": "Introduction",
                "sec_num": "1"
            },
            {
                "text": "The contributions of this paper include 1) incorporating homepages of entities, and 2) recognizing fine-grained types of entities for improving entity ranking. Furthermore, we propose an unsupervised method of generating training examples for fine-grained entity recognition and exploit multiple-contexts of entities as classification features. In related studies, only single-contexts of entities are employed. The experimental results in terms of the TREC 2010 entity track test data set demonstrate that the nDCG@R improvements of our three proposals, i.e., dependency-tree similarity, incorporating homepage and recognizing fine-grained named entity components, are 2.3%, 4.1%, and 2.1%, respectively. Compared with baseline, the accumulative improvements of our REF system in terms of nDCG@R, P@1 and P@5 scores are 8.4%, 27.5%, and 12.0%, respectively.",
                "cite_spans": [],
                "ref_spans": [],
                "eq_spans": [],
                "section": "Introduction",
                "sec_num": "1"
            },
            {
                "text": "The TREC REF task is highly related to a combination of the TREC list QA and homepage finding, INEX entity ranking, and TREC expert search tasks. The TREC list QA task (2001) (2002) (2003) (2004) (2005) (2006) (2007) (Voorhees, 2003) required systems to assemble an unordered list of answer strings to factoid questions such as Who are six actors who have played Tevye in \"Fiddler on the Roof\"? The underlying information need is of a more informational nature. However, the REF task is situated in explorative search tasks. Moreover, the list QA task also does not require returning to the homepage for each answer string. In recent years, retrievalbased (Yang, 2003) , pattern-based (Ravichandran, 2002) , deep NLP-based (Moldovan, 2002; Harabagiu, 2003) , and supervised/unsupervised machine learning based approaches (Ittycheriah, 2002; Wu, 2007) have been proposed. The TREC homepage finding task (2001) (2002) (2003) assumes that incoming queries (like \"IJCNLP 2011\") are attempts to navigate to the homepage of a particular web site (http://www.ijcnlp2011.org/). The TREC expert search task ( ) (Nick, 2005 focused on creating an ordered list of experts who have skills and experiments on a specific topic with enterprise data. Most of the proposed approaches generally fall into two categories: generative language models and discriminative models. For example, Balog (2006) proposed profile-centric (directly models the knowledge of an expert from associated documents) and document-centric (locates documents on the topic and then finds the associated experts) generative language models (LMs). Cao (2005) proposed a two-stage language model consisting of a document relevance and co-occurrence model. There are many other generative probabilistic models such as (Fang, 2007; Serdyukov, 2008) . proposed a principled relevance-based discriminative model that integrates a variety of document evidence and document candidate association features for improving expert searching. The INEX entity ranking task (2007-2010) (Vries, 2007) studies ranking of Wikipedia entities to a query topic. Apart from estimating similarities between Wikipedia pages and the given query topic, many systems (Pehcevski, 2008) have exploited Wikipedia link structure and Wikipedia categories, for instance, estimating overlap between the set of categories associated with target Wikipedia pages and the categories specified in a given query topic.",
                "cite_spans": [
                    {
                        "start": 168,
                        "end": 174,
                        "text": "(2001)",
                        "ref_id": null
                    },
                    {
                        "start": 175,
                        "end": 181,
                        "text": "(2002)",
                        "ref_id": null
                    },
                    {
                        "start": 182,
                        "end": 188,
                        "text": "(2003)",
                        "ref_id": null
                    },
                    {
                        "start": 189,
                        "end": 195,
                        "text": "(2004)",
                        "ref_id": null
                    },
                    {
                        "start": 196,
                        "end": 202,
                        "text": "(2005)",
                        "ref_id": null
                    },
                    {
                        "start": 203,
                        "end": 209,
                        "text": "(2006)",
                        "ref_id": null
                    },
                    {
                        "start": 210,
                        "end": 216,
                        "text": "(2007)",
                        "ref_id": null
                    },
                    {
                        "start": 217,
                        "end": 233,
                        "text": "(Voorhees, 2003)",
                        "ref_id": "BIBREF9"
                    },
                    {
                        "start": 656,
                        "end": 668,
                        "text": "(Yang, 2003)",
                        "ref_id": "BIBREF12"
                    },
                    {
                        "start": 685,
                        "end": 705,
                        "text": "(Ravichandran, 2002)",
                        "ref_id": null
                    },
                    {
                        "start": 723,
                        "end": 739,
                        "text": "(Moldovan, 2002;",
                        "ref_id": "BIBREF5"
                    },
                    {
                        "start": 740,
                        "end": 756,
                        "text": "Harabagiu, 2003)",
                        "ref_id": "BIBREF29"
                    },
                    {
                        "start": 821,
                        "end": 840,
                        "text": "(Ittycheriah, 2002;",
                        "ref_id": "BIBREF1"
                    },
                    {
                        "start": 841,
                        "end": 850,
                        "text": "Wu, 2007)",
                        "ref_id": "BIBREF34"
                    },
                    {
                        "start": 902,
                        "end": 908,
                        "text": "(2001)",
                        "ref_id": null
                    },
                    {
                        "start": 909,
                        "end": 915,
                        "text": "(2002)",
                        "ref_id": null
                    },
                    {
                        "start": 916,
                        "end": 922,
                        "text": "(2003)",
                        "ref_id": null
                    },
                    {
                        "start": 1098,
                        "end": 1113,
                        "text": "( ) (Nick, 2005",
                        "ref_id": "BIBREF23"
                    },
                    {
                        "start": 1370,
                        "end": 1382,
                        "text": "Balog (2006)",
                        "ref_id": "BIBREF16"
                    },
                    {
                        "start": 1605,
                        "end": 1615,
                        "text": "Cao (2005)",
                        "ref_id": "BIBREF36"
                    },
                    {
                        "start": 1773,
                        "end": 1785,
                        "text": "(Fang, 2007;",
                        "ref_id": "BIBREF11"
                    },
                    {
                        "start": 1786,
                        "end": 1802,
                        "text": "Serdyukov, 2008)",
                        "ref_id": "BIBREF25"
                    },
                    {
                        "start": 2197,
                        "end": 2214,
                        "text": "(Pehcevski, 2008)",
                        "ref_id": "BIBREF15"
                    }
                ],
                "ref_spans": [],
                "eq_spans": [],
                "section": "Related Work",
                "sec_num": "2"
            },
            {
                "text": "The TREC REF task (2009 aims at entity-oriented search on the Web. The most typical system is a cascade of the following components. (1) Document Retriever retrieves top relevant documents to a given query from the given Clueweb09 collection with 503 million English pages. (2) Entity Extractor extracts candidate entities that match the given target types from the top relevant documents by using entity repositories such as Wikipedia, or using named entity recognizers.",
                "cite_spans": [
                    {
                        "start": 4,
                        "end": 23,
                        "text": "TREC REF task (2009",
                        "ref_id": null
                    }
                ],
                "ref_spans": [],
                "eq_spans": [],
                "section": "Related Work",
                "sec_num": "2"
            },
            {
                "text": "(3) Entity Ranker estimates the probabilities of the extracted entities being answer entities by using supporting documents and/or snippets in which entities and queries co-occur. A number of language modeling techniques borrowed from expert search systems were employed Li, 2010) . 4Homepage Finder assigns primary homepages for the top ranked entity names by using entity names as queries, or homepage identifiers. Table 1 compares these tasks from four aspects.",
                "cite_spans": [
                    {
                        "start": 271,
                        "end": 280,
                        "text": "Li, 2010)",
                        "ref_id": "BIBREF26"
                    }
                ],
                "ref_spans": [
                    {
                        "start": 417,
                        "end": 424,
                        "text": "Table 1",
                        "ref_id": "TABREF1"
                    }
                ],
                "eq_spans": [],
                "section": "Related Work",
                "sec_num": "2"
            },
            {
                "text": "We can see that TREC entity ranking task is very complicated, and each component is an independent research topic in the fields of NLP and IR. This paper cannot cover all of them, and only focuses on Entity Ranker component, that is, given a query Q, and a list of extracted entities E = {e i |i = 1, 2, ...n} associated with their homepages H = {h e i |i = 1, 2, ..., n}, how to effectively rank these entities. The other three components are beyond the scope of this paper. For better understanding of the REF system, we simply introduce them. Our Document Retriever first employs Yahoo! BOSS API 2 to search relevant pages from the Web and then map them to documents in Clueweb09. Since one lesson from TREC 2009 is that commercial search engines such as Yahoo! are generally superior in locating relevant documents for the search engine, we used the Indri tool for building. In Entity Extractor, an NER tool developed at UIUC (Ratinov, 2009) 3 is employed. In particular, phrases/words tagged with PER, ORG, LOC and MISC tags are extracted when the target entities are people, organizations, locations, and products, respectively. For Homepage Finder, the DBpedia homepage data 4 is used to train a binary classifier and features are similar to (Upstill, 2003) . It is noted that we reverse the sequence of the Entity Ranker and Homepage Finder to enable incorporating homepage for ranking (introduced in section 3.3), that is, we first assign homepage for each entity, and then rank them.",
                "cite_spans": [
                    {
                        "start": 930,
                        "end": 945,
                        "text": "(Ratinov, 2009)",
                        "ref_id": "BIBREF18"
                    },
                    {
                        "start": 1249,
                        "end": 1264,
                        "text": "(Upstill, 2003)",
                        "ref_id": "BIBREF31"
                    }
                ],
                "ref_spans": [],
                "eq_spans": [],
                "section": "Our System",
                "sec_num": "3"
            },
            {
                "text": "In the context of expert search, the task is to find out what is the probability of a candidate person being an expert to a query. The REF system can be simply regarded as the task of estimating p(e i |Q), the probability of an entity e i being answer entity given a query Q. Therefore, approaches proposed in expert search can be used for entity finding. In TREC expert search, document model (referred as Model 2) (Balog, 2006) turned out to be one of the most prominent and effective models for estimating p(e i |Q). Model 2 is also used as our baseline, which can be expressed by,",
                "cite_spans": [
                    {
                        "start": 416,
                        "end": 429,
                        "text": "(Balog, 2006)",
                        "ref_id": "BIBREF16"
                    }
                ],
                "ref_spans": [],
                "eq_spans": [],
                "section": "Baseline",
                "sec_num": "3.1"
            },
            {
                "text": "p(e i |Q) \u221d n j=1 p(Q|es ij ) * p(e i |es ij , Q) (1)",
                "cite_spans": [],
                "ref_spans": [],
                "eq_spans": [],
                "section": "Baseline",
                "sec_num": "3.1"
            },
            {
                "text": "In (1) es ij stands for the j-th supporting snippet from which entity e i is extracted, n is the number of supporting snippets, p(Q|es ij ) denotes the relevance between query and supporting snippet, and can be relatively easy to determine using a language model (the KL-divergence language model used in this paper), p(e i |es ij , Q) denotes the cooccurrence of the query and entity in the snippet. Because unique characteristics of the W3C corpus used in expert search, meta-based co-occurrence model is commonly used. In entity ranking task, the KL-divergence language model is adopted to calculate p(e i |es ij , Q). Model 2 can be further improved in the context of REF task as follows.",
                "cite_spans": [],
                "ref_spans": [],
                "eq_spans": [],
                "section": "Baseline",
                "sec_num": "3.1"
            },
            {
                "text": "To improve unigram KL-divergence language model that can not capture relations between query words, this paper adopts a dependency tree-based similarity algorithm to calculate p(Q|es ij ), which can be expressed by,",
                "cite_spans": [],
                "ref_spans": [],
                "eq_spans": [],
                "section": "Improvement 1: Dependency Tree-based Similarity",
                "sec_num": "3.2"
            },
            {
                "text": "EQUATION",
                "cite_spans": [],
                "ref_spans": [],
                "eq_spans": [
                    {
                        "start": 0,
                        "end": 8,
                        "text": "EQUATION",
                        "ref_id": "EQREF",
                        "raw_str": "p(Q|es ij ) \u221d DP Q \u2229 DP es ij |DP Q | \u00d7 |DP es ij |",
                        "eq_num": "(2)"
                    }
                ],
                "section": "Improvement 1: Dependency Tree-based Similarity",
                "sec_num": "3.2"
            },
            {
                "text": "where DP Q and DP es ij stand for a set of sub-trees generated from dependency trees of query Q and text snippet es ij , respectively. Dependency trees are obtained by parsing Q and es ij using Lin's dependency parser, Minipar 5 , and the subtree is defined as any node up to its two descendants and extracted with the Freqt toolkit 6 .",
                "cite_spans": [],
                "ref_spans": [],
                "eq_spans": [],
                "section": "Improvement 1: Dependency Tree-based Similarity",
                "sec_num": "3.2"
            },
            {
                "text": "The goal of the REF task is to return homepages representing entities to a query, and homepages sometimes contain valuable information for ranking. Therefore, it is easy and necessary to incorporate homepages of entities in ranking. As input in entity finding, we receive a query Q, a list of candidate entities E = {e i |i = 1, 2, ..., n} associated with their homepages H = {h e i |i = 1, 2, ..., n}. The Entity Ranker can be reformulated to estimate a conditional probability p(e i , h e i |Q). The top k entities with their homepages are deemed the most probable answer entities. By assuming entity e i is independent of its homepage h e i , we obtain,",
                "cite_spans": [],
                "ref_spans": [],
                "eq_spans": [],
                "section": "Improvement 2: Incorporating Homepage",
                "sec_num": "3.3"
            },
            {
                "text": "EQUATION",
                "cite_spans": [],
                "ref_spans": [],
                "eq_spans": [
                    {
                        "start": 0,
                        "end": 8,
                        "text": "EQUATION",
                        "ref_id": "EQREF",
                        "raw_str": "p(e i , h e i |Q) = p(e i |Q) \u00d7 p(h e i |Q)",
                        "eq_num": "(3)"
                    }
                ],
                "section": "Improvement 2: Incorporating Homepage",
                "sec_num": "3.3"
            },
            {
                "text": "where p(e i |Q) stands for the probability of entity e i being an answer given query Q, and can be calculated using Equation (1) and (2), p(h e i |Q) stands for the probability of homepage h e i being an answer given query Q. By applying the Bayes' Theorem and assuming that p(h e i ) is uniform for all homepages h e i , we obtain,",
                "cite_spans": [],
                "ref_spans": [],
                "eq_spans": [],
                "section": "Improvement 2: Incorporating Homepage",
                "sec_num": "3.3"
            },
            {
                "text": "p(h e i |Q) = p(Q|h e i ) \u00d7 p(h e i ) p(Q) \u221d p(Q|h e i )",
                "cite_spans": [],
                "ref_spans": [],
                "eq_spans": [],
                "section": "Improvement 2: Incorporating Homepage",
                "sec_num": "3.3"
            },
            {
                "text": "(4) In some cases, homepages such as that of racecar driver Michael Schumacher (http://www. michael-schumacher.de/) do not contain any valuable information but intend to greet visitors and provide information about the site or its owner. Thus, we retrieve text snippets hs e i from a homepage site using query Q to build a back-off model for p(h e i |Q) built from the homepage (the opening or main page of the homepage site). Finally, we can obtain,",
                "cite_spans": [],
                "ref_spans": [],
                "eq_spans": [],
                "section": "Improvement 2: Incorporating Homepage",
                "sec_num": "3.3"
            },
            {
                "text": "p(Q|h e i ) = \u03b1 \u00d7 p(Q|h e i ) + \u03b2 \u00d7 p(Q|hs e i ) (5)",
                "cite_spans": [],
                "ref_spans": [],
                "eq_spans": [],
                "section": "Improvement 2: Incorporating Homepage",
                "sec_num": "3.3"
            },
            {
                "text": "where \u03b1 + \u03b2 = 1, p(Q|h e i ) and p(Q|hs e i ) are estimated using the KL-divergence language model.",
                "cite_spans": [],
                "ref_spans": [],
                "eq_spans": [],
                "section": "Improvement 2: Incorporating Homepage",
                "sec_num": "3.3"
            },
            {
                "text": "In short, conditional probability p(e i , h e i |Q) of the likelihood of entity e i with its homepage h e i being answer is calculated by using Equation 3, (5), (1) and (2).",
                "cite_spans": [],
                "ref_spans": [],
                "eq_spans": [],
                "section": "Improvement 2: Incorporating Homepage",
                "sec_num": "3.3"
            },
            {
                "text": "As mentioned, entities are extracted by using NER tool. There exist two problems. First, the NER tool can only identify coarse-grained types of entities such as organizations or locations. However, users' queries sometimes specify finegrained types of named entities such as airlines, universities, or actresses. Second, many incorrect entities are extracted. The main reason lies in: the NER tool is trained on newspapers, but we use it to tag web data. Therefore, it is necessary to filter out or negatively reward entities that do not match the fine-grained entity types if specified in queries. For example, this step can hopefully remove or negatively reward the extracted entities that are not airlines for the TREC 2009 test query shown in Figure 1 . Many semi-supervised methods have been proposed to recognize fine-grained types of entities. For example, Hearst (1992) used lexical patterns such as \"X, such as Y\". Fleischman (2002) employed a supervised learning method that considered the local context surrounding the entity as well as global semantic information. Etzioni (2005) started with a set of \"predicates\" and bootstrapped the extraction process from highprecision generic patterns. Oh (2009) exploited Wikipedia structure information and textual context to determine fine-grained types of Wikipedia entities. Generally, these methods mainly exploit the single-context of an entity as classification feature, which may result in errors in cases in which the relation between entity and its fine-grained type is not explicitly expressed.",
                "cite_spans": [
                    {
                        "start": 864,
                        "end": 877,
                        "text": "Hearst (1992)",
                        "ref_id": "BIBREF21"
                    },
                    {
                        "start": 924,
                        "end": 941,
                        "text": "Fleischman (2002)",
                        "ref_id": "BIBREF22"
                    },
                    {
                        "start": 1077,
                        "end": 1091,
                        "text": "Etzioni (2005)",
                        "ref_id": "BIBREF24"
                    },
                    {
                        "start": 1204,
                        "end": 1213,
                        "text": "Oh (2009)",
                        "ref_id": "BIBREF14"
                    }
                ],
                "ref_spans": [
                    {
                        "start": 747,
                        "end": 755,
                        "text": "Figure 1",
                        "ref_id": "FIGREF0"
                    }
                ],
                "eq_spans": [],
                "section": "Improvement 3: Fine-grained Entity Recognition",
                "sec_num": "3.4"
            },
            {
                "text": "Our proposal differs: 1) we utilize multiple contexts in which entities and their fine-grained types co-occur, 2) multiple contexts obtained by querying the Web with entities and their fine-grained types are helpful to disambiguate entities, 3) a dependency pattern-based approach is proposed for fine-grained classification of named entities. More specifically, our goal is to assign a class label (\"yes\" or \"no\") for each entity, fine-grained type pair. A \"yes\" means the entity belongs to the corresponding fine-grained type. Otherwise, it does not. The details are as follows.",
                "cite_spans": [],
                "ref_spans": [],
                "eq_spans": [],
                "section": "Improvement 3: Fine-grained Entity Recognition",
                "sec_num": "3.4"
            },
            {
                "text": "A certain number of entity e, its fine-grained type f gt, multi-contexts they co-occur mc training triples are needed to build a classifier of finegrained entities. The key challenge here is to prepare positive and negative e, f gt pairs. A Wikipedia article usually starts with a definition sentence like \"Continental Airlines is an American airline based and headquartered in Continental Center I in downtown Houston, Texas.\" We find that it is practicable to automatically extract entity (\"Continental Airlines\" in this example) and its fine-grained type (\"airline\") from such well-formed sentences. To extract the pairs from these definition sentences, we first use Minipar to parse all Wikipedia definition sentences and then extract the pairs using heuristic rules such as (be (Wikipedia-entity) (fine-grained-type)). In this example, Continental Airlines, airline is extracted. Finally, 41,495 pairs are generated. These pairs will be used as positive instances. In order to construct negative training pairs, we first adopt the NER tool to recognize named entities in the Wikipedia definition sentences, and then pair the fine-grained type and the identified entities, except for the Wikipedia entity, as negative examples. For example, Continental Center I, airline , Houston, airline , and Texas, airline pairs are generated. Finally, 122,686 negative pairs are collected from Wikipedia.",
                "cite_spans": [],
                "ref_spans": [],
                "eq_spans": [],
                "section": "Step-1: Preparation of Training Examples",
                "sec_num": "3.4.1"
            },
            {
                "text": "Multi-context mc can be easily obtained by querying a search engine with the entity and its type and merging the first k snippets returned. Formally, mc = k j=1 s j , where s j denotes the j-th snippet. For ambiguous entities such as \"Michael Collins\", it is hard to recognize their fine-grained types with fewer frequencies from multiple contexts obtained by querying the Web with entities only. Multiple contexts learned with entities and their fine-grained types can partially solve this problem.",
                "cite_spans": [],
                "ref_spans": [],
                "eq_spans": [],
                "section": "Step-1: Preparation of Training Examples",
                "sec_num": "3.4.1"
            },
            {
                "text": "In order to handle long distance relations between words, dependency patterns are extracted as features for classification. First, textual contexts of e, f gt, mc triples are parsed using Lin's Minipar. Then, the shortest dependency paths between e and f gt are extracted as dependency patterns. Figure 2 shows two examples. To reduce the di- mensionality of the feature space, we calculate the precision of each dependency pattern by using the equation,",
                "cite_spans": [],
                "ref_spans": [
                    {
                        "start": 296,
                        "end": 304,
                        "text": "Figure 2",
                        "ref_id": "FIGREF1"
                    }
                ],
                "eq_spans": [],
                "section": "Step-2: Building Classifier",
                "sec_num": "3.4.2"
            },
            {
                "text": "precison = Cnt p /(Cnt p + Cnt n ),",
                "cite_spans": [],
                "ref_spans": [],
                "eq_spans": [],
                "section": "Step-2: Building Classifier",
                "sec_num": "3.4.2"
            },
            {
                "text": "where, Cnt p and Cnt n denote total numbers of patterns occurring in positive and negative triples, respectively. We sort the extracted dependency patterns in deceasing order of precision and empirically select the top 500 patterns as classification features. For the classifier, we employ multivariate classification SVMs that can directly optimize a large class of performance measures such as F 1 -Score, prec@k and rec@k (the precision and recall of a classifier that predicts exactly k = 100 examples to be positive) (Joachims, 2005) . For our experiment we held out 500 pairs from each of the positive and negative instances for testing. The remainder are used for training. Table 2 reports the results on the testing data. These results are quite promising. The classifier optimizing F 1 -Score is finally used in our REF system. from the narrative field of query Q according to the predefined heuristic rules such as the head of the first non-stop noun phrase being fine-grained. For exmaple, gallery in \"What art galleries are located in Bethesda, Maryland?\" is identified as fine-grained type. For each entity e i extracted via the Entity Extractor, the following steps are performed. (1) obtain textual contexts by querying the Yahoo! search engine with entity e i and the identified finegrained type f gt Q , and merging the Yahoo! snippets returned. (2) parse contexts using Lin's Minipar and extract dependency patterns between e i and f gt Q . (3) employ the classifier to determine whether the entity e i belongs to the fine-grained type f gt Q , and remove or negatively reward the entities that are not fine-grained type identified from the query.",
                "cite_spans": [
                    {
                        "start": 522,
                        "end": 538,
                        "text": "(Joachims, 2005)",
                        "ref_id": "BIBREF30"
                    }
                ],
                "ref_spans": [
                    {
                        "start": 681,
                        "end": 688,
                        "text": "Table 2",
                        "ref_id": null
                    }
                ],
                "eq_spans": [],
                "section": "Step-2: Building Classifier",
                "sec_num": "3.4.2"
            },
            {
                "text": "Our experiments are conducted in the context of the TREC 2010 REF task. Relevance judgements in the TREC were performed in two stages. In phase one, all participant systems were pooled to a depth of the 20. The submitted homepages were judged on a three-point relevance scale: (2) primary homepage devoted to and in control of the entity, (1) relevant homepage devoted to the entity, but is not in control of the entity, and (0) nonrelevant homepage that only mentions the entity but is not about the entity. Note that the Wikipedia page of a given entity is regarded as non-relevant by definition in TREC 2010. In phase two, homepages belonging to the same entity are grouped together. The test set used in the TREC 2010 entity track contains 50 test queries. In the official evaluation, only 47 test queries are used because no answers to the other three queries are found. Among 47 test queries, 31 are for organization, 7 for location, 8 for person, and 1 for product name. The average number of answered homepages per topic is 14 .",
                "cite_spans": [],
                "ref_spans": [],
                "eq_spans": [],
                "section": "Experiments",
                "sec_num": "4"
            },
            {
                "text": "The TREC metrics are based on the homepages only because the ultimate goal of the REF system is to find the homepages of the entities. The main metric is nDCG@R; that is, the normalized discounted cumulative gain at rank R (the number of primary and relevant homepages for that topic) where a record with a primary gets a gain of 3, and a record with a relevant gets a gain of 1. We also report P@N, that is, the fraction of primary homepages in the first N ranks. Experimental results are computed using the eval-entity.pl script released by TREC. Table 3 reports the results of the four runs. Best T and Median T denote the best and median scores among all TREC 2010 participants' systems, respectively. Perfect O means the manual ranking system, which can indicate the performance ceiling that our Entity Ranker can achieve. Our comb denotes the proposed system that negatively reward all entities not belonging to the fine-grained entity type by simply putting them at the end of the ranking list.",
                "cite_spans": [],
                "ref_spans": [
                    {
                        "start": 549,
                        "end": 556,
                        "text": "Table 3",
                        "ref_id": null
                    }
                ],
                "eq_spans": [],
                "section": "Experiments",
                "sec_num": "4"
            },
            {
                "text": "nDCG@R P@1 P@5 P@10 Our comb .1865",
                "cite_spans": [],
                "ref_spans": [],
                "eq_spans": [],
                "section": "Overall Performance",
                "sec_num": "4.1"
            },
            {
                "text": ". .38 --- Table 3 : Comparison of four runs.",
                "cite_spans": [],
                "ref_spans": [
                    {
                        "start": 10,
                        "end": 17,
                        "text": "Table 3",
                        "ref_id": null
                    }
                ],
                "eq_spans": [],
                "section": "Overall Performance",
                "sec_num": "4.1"
            },
            {
                "text": "The results demonstrate that: i) Our comb significantly improves the median performance of the TREC participant systems from 12% to 18.65% in terms of nDCG@R. However, Perfect O (the performance ceiling) is much high than our automatic system, Our comb . This means that there is still much room for improving the entity ranking component. ii) Figure 3 shows the performance of each target type. Product-type queries achieve a worse score due to poor product (PRO) name recognition of the NER tool. The best P@1 score is obtained for organization (ORG) type queries. The nDCG@R score for the person (PER) type is, however, better than that for ORG-type queries. This is because the average number of answer homepages for the ORG-type (29.5) is significantly larger that that of the PERtype (10.5), and the recall for ORG type queries is relatively poor. iii) The Best T (Yang, 2010) is even better than our Perfect O . This indicates that the recall of our entity extraction is unsatisfactory. Note that this paper is mainly concerned with entity ranking, and entity extraction is not the scope of this paper. Yet the proposed methods can be incorporated into Best T and it can be expected to further improve its performance. Because Best T only use co-occurrence information between entities in ranking. For better understanding, Table 4 analyzes the recalls of the answer entities in the Document Retriever and Entity Extractor modules. #que represents the number of queries in which at least one answer entity is contained. #ent represents the number of answer entities of all test queries contained. This table indicates that the recall of the Entity Extractor is only 37% (= 266/715). The following sections mainly analyze the impacts of the dependency tree-based similarity, incorporating homepage and the fine-grained entity recognition to the REF system; thus, we exclude the queries for which no answer entities are extracted in the Entity Extractor, and the following experiments are based on 40 queries of the TREC 2010 test set.",
                "cite_spans": [
                    {
                        "start": 870,
                        "end": 882,
                        "text": "(Yang, 2010)",
                        "ref_id": "BIBREF27"
                    }
                ],
                "ref_spans": [
                    {
                        "start": 344,
                        "end": 352,
                        "text": "Figure 3",
                        "ref_id": "FIGREF2"
                    },
                    {
                        "start": 1331,
                        "end": 1338,
                        "text": "Table 4",
                        "ref_id": "TABREF5"
                    }
                ],
                "eq_spans": [],
                "section": "Overall Performance",
                "sec_num": "4.1"
            },
            {
                "text": "Entity Recognition Table 5 shows the contributions of the dependency tree-based similarity (DTBS), incorporating homepage information (HP), and fine-grained named entity recognition (FG-NER). The baseline is Model 2 discussed in section 3.1. Significance tests are conducted. \u2020 : significantly better than the system without this component at the p = 0.05 level using two-sided t-tests; : significantly better at the 0.01 level.",
                "cite_spans": [],
                "ref_spans": [
                    {
                        "start": 19,
                        "end": 26,
                        "text": "Table 5",
                        "ref_id": null
                    }
                ],
                "eq_spans": [],
                "section": "Impact of Homepage and Fine-grained",
                "sec_num": "4.2"
            },
            {
                "text": "nDCG@R P@1 P@5 P@10 Table 5 : Contribution of each component.",
                "cite_spans": [],
                "ref_spans": [
                    {
                        "start": 20,
                        "end": 27,
                        "text": "Table 5",
                        "ref_id": null
                    }
                ],
                "eq_spans": [],
                "section": "Impact of Homepage and Fine-grained",
                "sec_num": "4.2"
            },
            {
                "text": "The experimental results indicate that: i) the DTBS method can greatly improve Baseline, e.g., the nDCG@R and P@1 scores are significantly improved by 16.9% and 100.0%, respectively. We expect this because the DTBS method considers the relation between words. ii) homepage (HP) can positively impact the REF system in terms of nDCG@R, P@5, and P@10 metrics, which, however, leads to a lower P@1 score. When a nonhomepage but one highly-related to the query is assigned as the homepage of an incorrect entity, incorporating homepage information will cause a negative influence. iii) the FG-NER can greatly improve the P@1 score from 20.0% to 40.0% and the P@10 score by 7.1% (not significant). This indicates that the FG-NER on TREC answer entities has nice precision and but poor recall. Table 2 , however, shows that our FG-NER can achieve promising precision and recall. It is hard for TREC non-famous entities to retrieve snippets from the Web that conform to the dependency patterns extracted from snippets of Wikipedia entities, which results in poor performance.",
                "cite_spans": [],
                "ref_spans": [
                    {
                        "start": 788,
                        "end": 795,
                        "text": "Table 2",
                        "ref_id": null
                    }
                ],
                "eq_spans": [],
                "section": "Impact of Homepage and Fine-grained",
                "sec_num": "4.2"
            },
            {
                "text": "In short, it is effective to use a dependency tree-based similarity, homepage information, and fine-grained named entity recognition in the REF system. Figure 4 shows the nDCG@R scores of Our comb and Baseline for each of the 40 queries.",
                "cite_spans": [],
                "ref_spans": [
                    {
                        "start": 152,
                        "end": 160,
                        "text": "Figure 4",
                        "ref_id": null
                    }
                ],
                "eq_spans": [],
                "section": "Impact of Homepage and Fine-grained",
                "sec_num": "4.2"
            },
            {
                "text": "The experiments above are based on homepages only in which correct entities with wrong homepages are not rewarded. This section discusses the performance based on named entities in which failures of finding homepage are ignored. In calculating nDCG@R, each answer entity gains 1 and a Figure 4 : nDCG@R score for each test query.",
                "cite_spans": [],
                "ref_spans": [
                    {
                        "start": 285,
                        "end": 293,
                        "text": "Figure 4",
                        "ref_id": null
                    }
                ],
                "eq_spans": [],
                "section": "Evaluation on Entity Names",
                "sec_num": "4.3"
            },
            {
                "text": "non-relevant entity gains 0. Figure 5 shows the performance. This figure indicates that the improvements from each proposed component are more significant when errors from homepage finding are ignored. For example, the absolute enhancements of the FG-NER in terms of P@1 and nDCG@R scores are 22.5%, and 3.1%, respectively. This experiment indicates that the Homepage Finder component needs to be improved.",
                "cite_spans": [],
                "ref_spans": [
                    {
                        "start": 29,
                        "end": 37,
                        "text": "Figure 5",
                        "ref_id": "FIGREF4"
                    }
                ],
                "eq_spans": [],
                "section": "Evaluation on Entity Names",
                "sec_num": "4.3"
            },
            {
                "text": "P@1 P@5 P@10 nDCG@R ",
                "cite_spans": [],
                "ref_spans": [],
                "eq_spans": [],
                "section": "Evaluation on Entity Names",
                "sec_num": "4.3"
            },
            {
                "text": "This paper focused on developing a model for retrieving homepages of entities relevant to a query from a huge collection, and proposed three algorithms for improvements: a dependency treebased similarity method, incorporating homepages of entities to supplement text snippets that the entities are from, and fine-grained classification of named entities. The comparison experiments on the TREC 2010 test data set showed that the proposed algorithms can significantly improve the system; e.g., the cumulative improvements of the nDCG@R, P@1, and P@5 scores over the Baseline reach 8.4%, 27.5%, and 12.0%, respectively. Moreover, our approaches can also be used in other tasks such as factoid QA. For example, in the TREC 2007 QA test set, about 50% questions (except for questions which answers are numeric and time expresses) contain fine-grained types of answers. Thus, our fine-grained entity recognition module can be expected to lead to improvements in QA systems.",
                "cite_spans": [],
                "ref_spans": [],
                "eq_spans": [],
                "section": "Conclusion",
                "sec_num": "5"
            },
            {
                "text": "In the future, we will work toward entity extraction and fine-grained named entity recognition. Table and list-based entity extraction may be essential due to the considerable number of answer entities scattered in tables, lists, and other structured forms. For example, answer entities to TREC 2010 query 29 (Find companies that are included in the Dow Jones industrial average.) are contained in a table at http://www.1728. com/dowjone2.htm. Li (2010) summarized the statistics of the TREC 2010 test queries in which answer entities are expressed in tables and lists. This means the NER tool trained by the newspaper corpus might fail at identifying the entities from tables and lists, and we have a great deal of work to do in order to correctly identify them. For fine-grained named entity recognition, more studies are needed on identifying finegrained types of non-famous entities. For example, it is hard to determine whether \"Rosenberg Gallery\" is a gallery from the snippets relevant to the query \"Rosenberg Gallery, gallery\".",
                "cite_spans": [
                    {
                        "start": 444,
                        "end": 453,
                        "text": "Li (2010)",
                        "ref_id": "BIBREF26"
                    }
                ],
                "ref_spans": [
                    {
                        "start": 96,
                        "end": 105,
                        "text": "Table and",
                        "ref_id": null
                    }
                ],
                "eq_spans": [],
                "section": "Conclusion",
                "sec_num": "5"
            },
            {
                "text": "TREC 2010 limits the track's scope to searches for instances of the organizations, people, locations and product entity types.",
                "cite_spans": [],
                "ref_spans": [],
                "eq_spans": [],
                "section": "",
                "sec_num": null
            },
            {
                "text": "http://developer.yahoo.com/ 3 http://l2r.cs.uiuc.edu/\u02dccogcomp",
                "cite_spans": [],
                "ref_spans": [],
                "eq_spans": [],
                "section": "",
                "sec_num": null
            },
            {
                "text": "http://dbpedia.org/About",
                "cite_spans": [],
                "ref_spans": [],
                "eq_spans": [],
                "section": "",
                "sec_num": null
            },
            {
                "text": "http://webdocs.cs.ualberta.ca/\u02dclindek 6 http://chasen.org/\u02dctaku/software",
                "cite_spans": [],
                "ref_spans": [],
                "eq_spans": [],
                "section": "",
                "sec_num": null
            }
        ],
        "back_matter": [],
        "bib_entries": {
            "BIBREF0": {
                "ref_id": "b0",
                "title": "A Noisy-Channel Approach to Question Answering",
                "authors": [
                    {
                        "first": "Abdessamad",
                        "middle": [],
                        "last": "Echihabi",
                        "suffix": ""
                    },
                    {
                        "first": "Daniel",
                        "middle": [],
                        "last": "Marcu",
                        "suffix": ""
                    }
                ],
                "year": 2003,
                "venue": "Proc. of ACL 2003",
                "volume": "",
                "issue": "",
                "pages": "",
                "other_ids": {},
                "num": null,
                "urls": [],
                "raw_text": "Abdessamad Echihabi and Daniel Marcu. 2003. A Noisy-Channel Approach to Question Answering. In Proc. of ACL 2003, Japan.",
                "links": null
            },
            "BIBREF1": {
                "ref_id": "b1",
                "title": "IBM's Statistical Question Answering System-TREC 11",
                "authors": [
                    {
                        "first": "Abraham",
                        "middle": [],
                        "last": "Ittycheriah",
                        "suffix": ""
                    },
                    {
                        "first": "Salim",
                        "middle": [],
                        "last": "Roukos",
                        "suffix": ""
                    }
                ],
                "year": 2002,
                "venue": "Proc. of TREC",
                "volume": "",
                "issue": "",
                "pages": "",
                "other_ids": {},
                "num": null,
                "urls": [],
                "raw_text": "Abraham Ittycheriah, and Salim Roukos. 2002. IBM's Statistical Question Answering System-TREC 11. In Proc. of TREC 2002.",
                "links": null
            },
            "BIBREF3": {
                "ref_id": "b3",
                "title": "Entity Ranking Track",
                "authors": [],
                "year": 2007,
                "venue": "Proc. of INEX",
                "volume": "",
                "issue": "",
                "pages": "",
                "other_ids": {},
                "num": null,
                "urls": [],
                "raw_text": "Entity Ranking Track. In Proc. of INEX 2007.",
                "links": null
            },
            "BIBREF4": {
                "ref_id": "b4",
                "title": "Fine-Grained Classification of Named Entities Exploiting Latent Semantic Kernels",
                "authors": [
                    {
                        "first": "Claudio",
                        "middle": [],
                        "last": "Giuliano",
                        "suffix": ""
                    }
                ],
                "year": 2009,
                "venue": "Proc. of CoNLL",
                "volume": "",
                "issue": "",
                "pages": "201--209",
                "other_ids": {},
                "num": null,
                "urls": [],
                "raw_text": "Claudio Giuliano. 2009. Fine-Grained Classification of Named Entities Exploiting Latent Semantic Ker- nels. In Proc. of CoNLL 2009, pp. 201-209.",
                "links": null
            },
            "BIBREF5": {
                "ref_id": "b5",
                "title": "LCC Tools for Question Answering",
                "authors": [
                    {
                        "first": "Dan",
                        "middle": [],
                        "last": "Moldovan",
                        "suffix": ""
                    },
                    {
                        "first": "Sanda",
                        "middle": [],
                        "last": "Harabagiu",
                        "suffix": ""
                    },
                    {
                        "first": "Roxana",
                        "middle": [],
                        "last": "Girju",
                        "suffix": ""
                    }
                ],
                "year": 2002,
                "venue": "Proc. of TREC",
                "volume": "",
                "issue": "",
                "pages": "",
                "other_ids": {},
                "num": null,
                "urls": [],
                "raw_text": "Dan Moldovan, Sanda Harabagiu, Roxana Girju, et al. 2002. LCC Tools for Question Answering. In Proc. of TREC 2002.",
                "links": null
            },
            "BIBREF6": {
                "ref_id": "b6",
                "title": "Overview of the TREC 2001 Web Track",
                "authors": [
                    {
                        "first": "David",
                        "middle": [],
                        "last": "Hawking",
                        "suffix": ""
                    },
                    {
                        "first": "Nick",
                        "middle": [],
                        "last": "Craswell",
                        "suffix": ""
                    }
                ],
                "year": 2001,
                "venue": "Proc. of TREC",
                "volume": "",
                "issue": "",
                "pages": "",
                "other_ids": {},
                "num": null,
                "urls": [],
                "raw_text": "David Hawking, and Nick Craswell. 2001. Overview of the TREC 2001 Web Track. In Proc. of TREC 2001.",
                "links": null
            },
            "BIBREF8": {
                "ref_id": "b8",
                "title": "Learning Surface Text Patterns for a Question Answering System",
                "authors": [],
                "year": 2002,
                "venue": "Proc. of ACL",
                "volume": "",
                "issue": "",
                "pages": "",
                "other_ids": {},
                "num": null,
                "urls": [],
                "raw_text": "Learning Surface Text Patterns for a Question An- swering System. In Proc. of ACL 2002.",
                "links": null
            },
            "BIBREF9": {
                "ref_id": "b9",
                "title": "Overview of the TREC 2003 Question Answering Track",
                "authors": [
                    {
                        "first": "Ellen",
                        "middle": [
                            "M"
                        ],
                        "last": "Voorhees",
                        "suffix": ""
                    }
                ],
                "year": 2003,
                "venue": "Proc. of TREC 2003",
                "volume": "",
                "issue": "",
                "pages": "54--68",
                "other_ids": {},
                "num": null,
                "urls": [],
                "raw_text": "Ellen M. Voorhees. 2003. Overview of the TREC 2003 Question Answering Track. In Proc. of TREC 2003, pp.54-68, USA.",
                "links": null
            },
            "BIBREF10": {
                "ref_id": "b10",
                "title": "YAGO: A Core of Semantic Knowledge Unifying WordNet and Wikipedia",
                "authors": [
                    {
                        "first": "Fabian",
                        "middle": [
                            "M"
                        ],
                        "last": "Suchanek",
                        "suffix": ""
                    },
                    {
                        "first": "Gjergji",
                        "middle": [],
                        "last": "Kasneci",
                        "suffix": ""
                    },
                    {
                        "first": "Gerhard",
                        "middle": [],
                        "last": "Weikum",
                        "suffix": ""
                    }
                ],
                "year": 2007,
                "venue": "Proc. of WWW",
                "volume": "",
                "issue": "",
                "pages": "697--706",
                "other_ids": {},
                "num": null,
                "urls": [],
                "raw_text": "Fabian M. Suchanek, Gjergji Kasneci, and Gerhard Weikum. 2007. YAGO: A Core of Semantic Knowl- edge Unifying WordNet and Wikipedia. In Proc. of WWW 2007, pp.697-706.",
                "links": null
            },
            "BIBREF11": {
                "ref_id": "b11",
                "title": "Probabilistic Models for Expert Finding",
                "authors": [
                    {
                        "first": "Hui",
                        "middle": [],
                        "last": "Fang",
                        "suffix": ""
                    },
                    {
                        "first": "Chengxiang",
                        "middle": [],
                        "last": "Zhai",
                        "suffix": ""
                    }
                ],
                "year": 2007,
                "venue": "Proc. of ECIR",
                "volume": "",
                "issue": "",
                "pages": "418--430",
                "other_ids": {},
                "num": null,
                "urls": [],
                "raw_text": "Hui Fang and ChengXiang Zhai. 2007. Probabilistic Models for Expert Finding. In Proc. of ECIR 2007, pp.418-430.",
                "links": null
            },
            "BIBREF12": {
                "ref_id": "b12",
                "title": "QUALIFIER: Question Answering by Lexical Fabric and External Resources",
                "authors": [
                    {
                        "first": "Hui",
                        "middle": [],
                        "last": "Yang",
                        "suffix": ""
                    },
                    {
                        "first": "Tat-Seng",
                        "middle": [],
                        "last": "Chua",
                        "suffix": ""
                    }
                ],
                "year": 2003,
                "venue": "Proc. of EACL",
                "volume": "",
                "issue": "",
                "pages": "363--370",
                "other_ids": {},
                "num": null,
                "urls": [],
                "raw_text": "Hui Yang, and Tat-Seng Chua. 2003. QUALIFIER: Question Answering by Lexical Fabric and External Resources. In Proc. of EACL 2003, pp.363-370.",
                "links": null
            },
            "BIBREF13": {
                "ref_id": "b13",
                "title": "Document Language Models, Query Models, and Risk Minimization for Information Retrieval",
                "authors": [
                    {
                        "first": "John",
                        "middle": [],
                        "last": "Lafferty",
                        "suffix": ""
                    },
                    {
                        "first": "Chengxiang",
                        "middle": [],
                        "last": "Zhai",
                        "suffix": ""
                    }
                ],
                "year": 2001,
                "venue": "Proc. of SIGIR",
                "volume": "",
                "issue": "",
                "pages": "",
                "other_ids": {},
                "num": null,
                "urls": [],
                "raw_text": "John Lafferty and Chengxiang Zhai. 2001. Docu- ment Language Models, Query Models, and Risk Minimization for Information Retrieval. In Proc. of SIGIR-2001.",
                "links": null
            },
            "BIBREF14": {
                "ref_id": "b14",
                "title": "Bilingual Co-Training for Monolingual Hyponymy-Relation Acquisition",
                "authors": [
                    {
                        "first": "Jong-Hoon",
                        "middle": [],
                        "last": "Oh",
                        "suffix": ""
                    },
                    {
                        "first": "Kiyotaka",
                        "middle": [],
                        "last": "Uchimoto",
                        "suffix": ""
                    },
                    {
                        "first": "Kentaro",
                        "middle": [],
                        "last": "Torisawa",
                        "suffix": ""
                    }
                ],
                "year": 2009,
                "venue": "Proc. of ACL 2010",
                "volume": "",
                "issue": "",
                "pages": "432--440",
                "other_ids": {},
                "num": null,
                "urls": [],
                "raw_text": "Jong-Hoon Oh, Kiyotaka Uchimoto, and Kentaro Tori- sawa. 2009. Bilingual Co-Training for Monolingual Hyponymy-Relation Acquisition. In Proc. of ACL 2010, pp.432-440.",
                "links": null
            },
            "BIBREF15": {
                "ref_id": "b15",
                "title": "Exploiting Locality of Wikipedia Links in Entity Ranking",
                "authors": [
                    {
                        "first": "Jovan",
                        "middle": [],
                        "last": "Pehcevski",
                        "suffix": ""
                    },
                    {
                        "first": "Anne-Marie",
                        "middle": [],
                        "last": "Vercoustre",
                        "suffix": ""
                    },
                    {
                        "first": "James",
                        "middle": [],
                        "last": "Thom",
                        "suffix": ""
                    }
                ],
                "year": 2008,
                "venue": "Proc. of ECIR",
                "volume": "",
                "issue": "",
                "pages": "",
                "other_ids": {},
                "num": null,
                "urls": [],
                "raw_text": "Jovan Pehcevski, Anne-Marie Vercoustre, and James Thom. 2008. Exploiting Locality of Wikipedia Links in Entity Ranking. In Proc. of ECIR 2008.",
                "links": null
            },
            "BIBREF16": {
                "ref_id": "b16",
                "title": "Formal Models for Expert Finding in Enterprise Corpora",
                "authors": [
                    {
                        "first": "Krisztian",
                        "middle": [],
                        "last": "Balog",
                        "suffix": ""
                    },
                    {
                        "first": "Leif",
                        "middle": [],
                        "last": "Azzopardi",
                        "suffix": ""
                    },
                    {
                        "first": "Maarten",
                        "middle": [],
                        "last": "De Rijke",
                        "suffix": ""
                    }
                ],
                "year": 2006,
                "venue": "Proc. of SIGIR",
                "volume": "",
                "issue": "",
                "pages": "43--50",
                "other_ids": {},
                "num": null,
                "urls": [],
                "raw_text": "Krisztian Balog, Leif Azzopardi, and Maarten de Rijke. 2006. Formal Models for Expert Finding in Enter- prise Corpora. In Proc. of SIGIR 2006, pp.43-50.",
                "links": null
            },
            "BIBREF17": {
                "ref_id": "b17",
                "title": "Overview of TREC 2010 Entity Track",
                "authors": [
                    {
                        "first": "Krisztian",
                        "middle": [],
                        "last": "Balog",
                        "suffix": ""
                    },
                    {
                        "first": "Leif",
                        "middle": [],
                        "last": "Azzopardi",
                        "suffix": ""
                    },
                    {
                        "first": "Maarten",
                        "middle": [],
                        "last": "De Rijke",
                        "suffix": ""
                    }
                ],
                "year": 2010,
                "venue": "Proc. of TREC",
                "volume": "",
                "issue": "",
                "pages": "",
                "other_ids": {},
                "num": null,
                "urls": [],
                "raw_text": "Krisztian Balog, Leif Azzopardi, and Maarten de Rijke. 2010. Overview of TREC 2010 Entity Track. In Proc. of TREC 2010.",
                "links": null
            },
            "BIBREF18": {
                "ref_id": "b18",
                "title": "Design Challenges and Misconceptions in Named Entity Recognition",
                "authors": [
                    {
                        "first": "Lev",
                        "middle": [],
                        "last": "Ratinov",
                        "suffix": ""
                    },
                    {
                        "first": "Dan",
                        "middle": [],
                        "last": "Roth",
                        "suffix": ""
                    }
                ],
                "year": 2009,
                "venue": "Proc. of CoNLL",
                "volume": "",
                "issue": "",
                "pages": "",
                "other_ids": {},
                "num": null,
                "urls": [],
                "raw_text": "Lev Ratinov and Dan Roth. 2009. Design Challenges and Misconceptions in Named Entity Recognition. In Proc. of CoNLL 2009.",
                "links": null
            },
            "BIBREF19": {
                "ref_id": "b19",
                "title": "Ranking Related Entities: Components and Analysis",
                "authors": [
                    {
                        "first": "Marc",
                        "middle": [],
                        "last": "Bron",
                        "suffix": ""
                    },
                    {
                        "first": "Krisztian",
                        "middle": [],
                        "last": "Balog",
                        "suffix": ""
                    },
                    {
                        "first": "Maarten",
                        "middle": [],
                        "last": "De Rijke",
                        "suffix": ""
                    }
                ],
                "year": 2010,
                "venue": "Proc. of CIKM",
                "volume": "",
                "issue": "",
                "pages": "",
                "other_ids": {},
                "num": null,
                "urls": [],
                "raw_text": "Marc Bron, Krisztian Balog, and Maarten de Rijke. 2010. Ranking Related Entities: Components and Analysis. In Proc. of CIKM 2010.",
                "links": null
            },
            "BIBREF20": {
                "ref_id": "b20",
                "title": "The University of Amsterdam at TREC 2010 Session, Entity, and Relevance Feedback",
                "authors": [
                    {
                        "first": "Marc",
                        "middle": [],
                        "last": "Bron",
                        "suffix": ""
                    },
                    {
                        "first": "Jiyin",
                        "middle": [],
                        "last": "He",
                        "suffix": ""
                    },
                    {
                        "first": "Katja",
                        "middle": [],
                        "last": "Hofmann",
                        "suffix": ""
                    }
                ],
                "year": 2010,
                "venue": "Proc. of TREC",
                "volume": "",
                "issue": "",
                "pages": "",
                "other_ids": {},
                "num": null,
                "urls": [],
                "raw_text": "Marc Bron, Jiyin He, Katja Hofmann, et al. 2010. The University of Amsterdam at TREC 2010 Session, Entity, and Relevance Feedback. In Proc. of TREC 2010.",
                "links": null
            },
            "BIBREF21": {
                "ref_id": "b21",
                "title": "Automatic Acquisition of Hyponyms from Large Text Corpora",
                "authors": [
                    {
                        "first": "Marti",
                        "middle": [
                            "A"
                        ],
                        "last": "Hearst",
                        "suffix": ""
                    }
                ],
                "year": 1992,
                "venue": "Proc. of COLING-92",
                "volume": "",
                "issue": "",
                "pages": "539--545",
                "other_ids": {},
                "num": null,
                "urls": [],
                "raw_text": "Marti A. Hearst. 1992. Automatic Acquisition of Hyponyms from Large Text Corpora. In Proc. of COLING-92, pp.539-545.",
                "links": null
            },
            "BIBREF22": {
                "ref_id": "b22",
                "title": "Fine Grained Classification of Named Entities",
                "authors": [
                    {
                        "first": "Michael",
                        "middle": [],
                        "last": "Fleischman",
                        "suffix": ""
                    },
                    {
                        "first": "Eduard",
                        "middle": [],
                        "last": "Hovy",
                        "suffix": ""
                    }
                ],
                "year": 2002,
                "venue": "Proc. of COLING-2002",
                "volume": "",
                "issue": "",
                "pages": "",
                "other_ids": {},
                "num": null,
                "urls": [],
                "raw_text": "Michael Fleischman and Eduard Hovy. 2002. Fine Grained Classification of Named Entities. In Proc. of COLING-2002.",
                "links": null
            },
            "BIBREF23": {
                "ref_id": "b23",
                "title": "Overview of the TREC-2005 Enterprise Track",
                "authors": [
                    {
                        "first": "Nick",
                        "middle": [],
                        "last": "Craswell",
                        "suffix": ""
                    },
                    {
                        "first": "P",
                        "middle": [],
                        "last": "Arjen",
                        "suffix": ""
                    },
                    {
                        "first": "Ian",
                        "middle": [],
                        "last": "De Vries",
                        "suffix": ""
                    },
                    {
                        "first": "",
                        "middle": [],
                        "last": "Soboroff",
                        "suffix": ""
                    }
                ],
                "year": 2005,
                "venue": "Proc. of TREC 2005",
                "volume": "",
                "issue": "",
                "pages": "1--7",
                "other_ids": {},
                "num": null,
                "urls": [],
                "raw_text": "Nick Craswell, Arjen P. de Vries, and Ian Soboroff. 2005. Overview of the TREC-2005 Enterprise Track. In Proc. of TREC 2005, pp.1-7.",
                "links": null
            },
            "BIBREF24": {
                "ref_id": "b24",
                "title": "Unsupervised Named-Entity Extraction from the Web: An Experimental Study",
                "authors": [
                    {
                        "first": "Oren",
                        "middle": [],
                        "last": "Etzioni",
                        "suffix": ""
                    },
                    {
                        "first": "Michael",
                        "middle": [],
                        "last": "Cafarella",
                        "suffix": ""
                    },
                    {
                        "first": "Doug",
                        "middle": [],
                        "last": "Downey",
                        "suffix": ""
                    }
                ],
                "year": 2005,
                "venue": "Artificial Intelligence",
                "volume": "165",
                "issue": "",
                "pages": "",
                "other_ids": {},
                "num": null,
                "urls": [],
                "raw_text": "Oren Etzioni, Michael Cafarella, Doug Downey, et al. 2005. Unsupervised Named-Entity Extraction from the Web: An Experimental Study. Artificial Intelli- gence, Volume 165 Issue 1.",
                "links": null
            },
            "BIBREF25": {
                "ref_id": "b25",
                "title": "Modeling multi-step relevance propagation for expert finding",
                "authors": [
                    {
                        "first": "Pavel",
                        "middle": [],
                        "last": "Serdyukov",
                        "suffix": ""
                    },
                    {
                        "first": "Djoerd",
                        "middle": [],
                        "last": "Henning Rode",
                        "suffix": ""
                    },
                    {
                        "first": "",
                        "middle": [],
                        "last": "Hiemstra",
                        "suffix": ""
                    }
                ],
                "year": 2008,
                "venue": "Proc. of CIKM",
                "volume": "",
                "issue": "",
                "pages": "",
                "other_ids": {},
                "num": null,
                "urls": [],
                "raw_text": "Pavel Serdyukov, Henning Rode, and Djoerd Hiemstra. 2008. Modeling multi-step relevance propagation for expert finding. In Proc. of CIKM 2008.",
                "links": null
            },
            "BIBREF26": {
                "ref_id": "b26",
                "title": "Searching for Entities: When Retrieval Meets Extraction",
                "authors": [
                    {
                        "first": "Qi",
                        "middle": [],
                        "last": "Li",
                        "suffix": ""
                    },
                    {
                        "first": "Daqing",
                        "middle": [],
                        "last": "He",
                        "suffix": ""
                    }
                ],
                "year": 2010,
                "venue": "Proc. of TREC",
                "volume": "",
                "issue": "",
                "pages": "",
                "other_ids": {},
                "num": null,
                "urls": [],
                "raw_text": "Qi Li and Daqing He. 2010. Searching for Entities: When Retrieval Meets Extraction. In Proc. of TREC 2010.",
                "links": null
            },
            "BIBREF27": {
                "ref_id": "b27",
                "title": "Reconstruct Logical Hierarchical Sitemap for Related Entity Finding",
                "authors": [
                    {
                        "first": "Qing",
                        "middle": [],
                        "last": "Yang",
                        "suffix": ""
                    },
                    {
                        "first": "Peng",
                        "middle": [],
                        "last": "Jiang",
                        "suffix": ""
                    },
                    {
                        "first": "Chunxia",
                        "middle": [],
                        "last": "Zhang",
                        "suffix": ""
                    }
                ],
                "year": 2010,
                "venue": "Proc. of TREC",
                "volume": "",
                "issue": "",
                "pages": "",
                "other_ids": {},
                "num": null,
                "urls": [],
                "raw_text": "Qing Yang, Peng Jiang, Chunxia Zhang, and et al. 2010. Reconstruct Logical Hierarchical Sitemap for Related Entity Finding. In Proc. of TREC 2010.",
                "links": null
            },
            "BIBREF28": {
                "ref_id": "b28",
                "title": "Entity Ranking using Wikipedia as a Pivot",
                "authors": [
                    {
                        "first": "Rianne",
                        "middle": [],
                        "last": "Kaptein",
                        "suffix": ""
                    },
                    {
                        "first": "Pavel",
                        "middle": [],
                        "last": "Serdyukov",
                        "suffix": ""
                    }
                ],
                "year": 2010,
                "venue": "Proc. of CIKM",
                "volume": "",
                "issue": "",
                "pages": "",
                "other_ids": {},
                "num": null,
                "urls": [],
                "raw_text": "Rianne Kaptein, Pavel Serdyukov, Arjen de Vries, and Jaap Kamps. 2010. Entity Ranking using Wikipedia as a Pivot. In Proc. of CIKM 2010.",
                "links": null
            },
            "BIBREF29": {
                "ref_id": "b29",
                "title": "Open-Domain Textual Question Answering Techniques",
                "authors": [
                    {
                        "first": "Sanda",
                        "middle": [
                            "M"
                        ],
                        "last": "Harabagiu",
                        "suffix": ""
                    },
                    {
                        "first": "Steven",
                        "middle": [
                            "J"
                        ],
                        "last": "Maiorano",
                        "suffix": ""
                    },
                    {
                        "first": "Marius",
                        "middle": [
                            "A"
                        ],
                        "last": "Pasca",
                        "suffix": ""
                    }
                ],
                "year": 2003,
                "venue": "In Natural Language Engineering",
                "volume": "9",
                "issue": "3",
                "pages": "1--38",
                "other_ids": {},
                "num": null,
                "urls": [],
                "raw_text": "Sanda M. Harabagiu, Steven J. Maiorano and Marius A. Pasca. 2003. Open-Domain Textual Question Answering Techniques. In Natural Language Engi- neering 9 (3): 1-38.",
                "links": null
            },
            "BIBREF30": {
                "ref_id": "b30",
                "title": "A Support Vector Method for Multivariate Performance Measures",
                "authors": [
                    {
                        "first": "Thorsten",
                        "middle": [],
                        "last": "Joachims",
                        "suffix": ""
                    }
                ],
                "year": 2005,
                "venue": "Proc. of ICML",
                "volume": "",
                "issue": "",
                "pages": "",
                "other_ids": {},
                "num": null,
                "urls": [],
                "raw_text": "Thorsten Joachims. 2005. A Support Vector Method for Multivariate Performance Measures. In Proc. of ICML 2005.",
                "links": null
            },
            "BIBREF31": {
                "ref_id": "b31",
                "title": "Query-Independent Evidence in Home Page Finding",
                "authors": [
                    {
                        "first": "Trystan",
                        "middle": [],
                        "last": "Upstill",
                        "suffix": ""
                    }
                ],
                "year": 2003,
                "venue": "ACM Transactions on Information Systems, Vol21, No3",
                "volume": "",
                "issue": "",
                "pages": "286--313",
                "other_ids": {},
                "num": null,
                "urls": [],
                "raw_text": "Trystan Upstill. 2003. Query-Independent Evidence in Home Page Finding. In ACM Transactions on Information Systems, Vol21, No3, pp.286-313.",
                "links": null
            },
            "BIBREF32": {
                "ref_id": "b32",
                "title": "Discriminative Models of Integrating Document Evidence and Document-Candidate Associations for Expert Search",
                "authors": [
                    {
                        "first": "Yi",
                        "middle": [],
                        "last": "Fang",
                        "suffix": ""
                    },
                    {
                        "first": "Luo",
                        "middle": [],
                        "last": "Si",
                        "suffix": ""
                    },
                    {
                        "first": "Aditya",
                        "middle": [
                            "P"
                        ],
                        "last": "Mathur",
                        "suffix": ""
                    }
                ],
                "year": 2010,
                "venue": "Proc. of SIGIR 2010",
                "volume": "",
                "issue": "",
                "pages": "683--690",
                "other_ids": {},
                "num": null,
                "urls": [],
                "raw_text": "Yi Fang, Luo Si, and Aditya P. Mathur. 2010. Discrim- inative Models of Integrating Document Evidence and Document-Candidate Associations for Expert Search. In Proc. of SIGIR 2010, pp.683-690.",
                "links": null
            },
            "BIBREF33": {
                "ref_id": "b33",
                "title": "Purdue at TREC 2010 Entity Track: A Probabilistic Framework for Matching Types Between Candidate and Target Entities",
                "authors": [
                    {
                        "first": "Yi",
                        "middle": [],
                        "last": "Fang",
                        "suffix": ""
                    },
                    {
                        "first": "Luo",
                        "middle": [],
                        "last": "Si",
                        "suffix": ""
                    },
                    {
                        "first": "Zhengtao",
                        "middle": [],
                        "last": "Yu",
                        "suffix": ""
                    }
                ],
                "year": 2010,
                "venue": "Proc. of TREC",
                "volume": "",
                "issue": "",
                "pages": "",
                "other_ids": {},
                "num": null,
                "urls": [],
                "raw_text": "Yi Fang, Luo Si, Zhengtao Yu, et al. 2010. Purdue at TREC 2010 Entity Track: A Probabilistic Frame- work for Matching Types Between Candidate and Target Entities. In Proc. of TREC 2010.",
                "links": null
            },
            "BIBREF34": {
                "ref_id": "b34",
                "title": "Learning Unsupervised SVM Classifier for Answer Selection in Web Question Answering",
                "authors": [
                    {
                        "first": "Youzheng",
                        "middle": [],
                        "last": "Wu",
                        "suffix": ""
                    },
                    {
                        "first": "Ruiqiang",
                        "middle": [],
                        "last": "Zhang",
                        "suffix": ""
                    },
                    {
                        "first": "Xinhui",
                        "middle": [],
                        "last": "Hu",
                        "suffix": ""
                    },
                    {
                        "first": "Hideki",
                        "middle": [],
                        "last": "Kashioka",
                        "suffix": ""
                    }
                ],
                "year": 2007,
                "venue": "Proc. of EMNLP-CoNLL",
                "volume": "",
                "issue": "",
                "pages": "",
                "other_ids": {},
                "num": null,
                "urls": [],
                "raw_text": "Youzheng Wu, Ruiqiang Zhang, Xinhui Hu, Hideki Kashioka. 2007. Learning Unsupervised SVM Classifier for Answer Selection in Web Question Answering. In Proc. of EMNLP-CoNLL 2007.",
                "links": null
            },
            "BIBREF35": {
                "ref_id": "b35",
                "title": "NiCT at TREC 2009: Employing Three Models for Entity Ranking Track",
                "authors": [
                    {
                        "first": "Youzheng",
                        "middle": [],
                        "last": "Wu",
                        "suffix": ""
                    },
                    {
                        "first": "Hideki",
                        "middle": [],
                        "last": "Kashioka",
                        "suffix": ""
                    }
                ],
                "year": 2009,
                "venue": "Proc. of TREC",
                "volume": "",
                "issue": "",
                "pages": "",
                "other_ids": {},
                "num": null,
                "urls": [],
                "raw_text": "Youzheng Wu and Hideki Kashioka. 2009. NiCT at TREC 2009: Employing Three Models for Entity Ranking Track. In Proc. of TREC 2009.",
                "links": null
            },
            "BIBREF36": {
                "ref_id": "b36",
                "title": "Research on expert search at enterprise track of TREC",
                "authors": [
                    {
                        "first": "Yunbo",
                        "middle": [],
                        "last": "Cao",
                        "suffix": ""
                    },
                    {
                        "first": "Jingjing",
                        "middle": [],
                        "last": "Liu",
                        "suffix": ""
                    },
                    {
                        "first": "Shenghua",
                        "middle": [],
                        "last": "Bao",
                        "suffix": ""
                    },
                    {
                        "first": "Hang",
                        "middle": [],
                        "last": "Li",
                        "suffix": ""
                    }
                ],
                "year": 2005,
                "venue": "Proc. of TREC",
                "volume": "",
                "issue": "",
                "pages": "",
                "other_ids": {},
                "num": null,
                "urls": [],
                "raw_text": "Yunbo Cao, Jingjing Liu, Shenghua Bao, and Hang Li. 2005. Research on expert search at enterprise track of TREC 2005. In Proc. of TREC 2005.",
                "links": null
            },
            "BIBREF37": {
                "ref_id": "b37",
                "title": "Question Answering as Question-Biased Term Extraction: A New Approach toward Multilingual QA",
                "authors": [
                    {
                        "first": "Yutaka",
                        "middle": [],
                        "last": "Sasaki",
                        "suffix": ""
                    }
                ],
                "year": 2005,
                "venue": "Proc. of ACL",
                "volume": "",
                "issue": "",
                "pages": "",
                "other_ids": {},
                "num": null,
                "urls": [],
                "raw_text": "Yutaka Sasaki. 2005. Question Answering as Question-Biased Term Extraction: A New Approach toward Multilingual QA. In Proc. of ACL 2005.",
                "links": null
            }
        },
        "ref_entries": {
            "FIGREF0": {
                "num": null,
                "uris": null,
                "type_str": "figure",
                "text": "Test query in TREC 2009 entity track."
            },
            "FIGREF1": {
                "num": null,
                "uris": null,
                "type_str": "figure",
                "text": "Entity) (Fine-grained Type)) (known (Entity) (as (Fine-grained Type))) Examples of dependency patterns."
            },
            "FIGREF2": {
                "num": null,
                "uris": null,
                "type_str": "figure",
                "text": "Results per topic type."
            },
            "FIGREF4": {
                "num": null,
                "uris": null,
                "type_str": "figure",
                "text": "Metrics based on named entities."
            },
            "TABREF1": {
                "content": "<table><tr><td>: Comparison of entity ranking tasks. W3C corpus is a simulation of enterprise data crawled from</td></tr><tr><td>public W3C (*.w3.org) sites in June 2004.</td></tr></table>",
                "num": null,
                "html": null,
                "type_str": "table",
                "text": ""
            },
            "TABREF2": {
                "content": "<table><tr><td/><td colspan=\"3\">Rec@k Prec@k F1-score</td></tr><tr><td>Precision</td><td>80.8</td><td>89.3</td><td>86.4</td></tr><tr><td>Recall</td><td>97.4</td><td>83.6</td><td>91.6</td></tr><tr><td>F-measure</td><td>88.3</td><td>86.4</td><td>88.9</td></tr><tr><td colspan=\"4\">Table 2: Fine-grained named entity classifiers op-</td></tr><tr><td colspan=\"2\">timizing different measures.</td><td/><td/></tr></table>",
                "num": null,
                "html": null,
                "type_str": "table",
                "text": "To use the classifier in the REF system, we recognize fine-grained type f gt Q of the target entity"
            },
            "TABREF4": {
                "content": "<table><tr><td/><td>Golden Answers a</td><td>Document Retriever b</td><td>Entity Extractor c</td></tr><tr><td>#que</td><td>47</td><td>45</td><td>40</td></tr><tr><td>#ent</td><td>715</td><td>384</td><td>266</td></tr><tr><td colspan=\"3\">a Golden answers are proved by TREC 2010</td><td/></tr><tr><td colspan=\"4\">http://trec.nist.gov/data/entity10.html</td></tr><tr><td colspan=\"4\">No answer entities are extracted for queries 28, 36, 37, 65, and 66.</td></tr></table>",
                "num": null,
                "html": null,
                "type_str": "table",
                "text": "No answer entities are retrieved for queries 34 and 44."
            },
            "TABREF5": {
                "content": "<table/>",
                "num": null,
                "html": null,
                "type_str": "table",
                "text": "Recalls of answer entities."
            }
        }
    }
}