File size: 37,771 Bytes
3c0072d
 
 
 
 
94acd36
3c0072d
617ead0
3c0072d
617ead0
3c0072d
 
94acd36
51be08d
3c0072d
 
 
 
 
 
 
4aed9bd
 
3c0072d
 
 
4aed9bd
f2e5f1e
99446b2
 
37e4776
f2e5f1e
37e4776
 
 
 
f2e5f1e
37e4776
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
f2e5f1e
37e4776
f2e5f1e
 
 
37e4776
 
 
 
f2e5f1e
37e4776
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
21f3804
f2e5f1e
21f3804
 
f2e5f1e
37e4776
 
 
 
f2e5f1e
37e4776
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
7ce5be9
37e4776
7ce5be9
 
f2e5f1e
37e4776
 
 
 
f2e5f1e
37e4776
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
f2e5f1e
 
 
 
 
37e4776
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
c7090ba
f2e5f1e
c7090ba
 
f2e5f1e
37e4776
 
 
 
f2e5f1e
37e4776
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
f2e5f1e
37e4776
 
f2e5f1e
 
37e4776
 
 
 
f2e5f1e
37e4776
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
f2e5f1e
 
 
 
 
 
 
 
 
 
21f3804
 
 
 
7ce5be9
 
 
 
c7090ba
 
 
 
3c0072d
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
99446b2
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
---
annotations_creators:
- no-annotation
language_creators:
- machine-generated
language:
- de
- en
- es
- fr
- it
- nl
license:
- cc0-1.0
multilinguality:
- multilingual
size_categories:
- 100K<n<1M
source_datasets:
- original
task_categories:
- text-generation
- fill-mask
- other
task_ids:
- language-modeling
- masked-language-modeling
pretty_name: British Library Books
tags:
- digital-humanities-research
dataset_info:
- config_name: '1500_1899'
  features:
  - name: record_id
    dtype: string
  - name: date
    dtype: timestamp[s]
  - name: raw_date
    dtype: string
  - name: title
    dtype: string
  - name: place
    dtype: string
  - name: empty_pg
    dtype: bool
  - name: text
    dtype: string
  - name: pg
    dtype: int32
  - name: mean_wc_ocr
    dtype: float32
  - name: std_wc_ocr
    dtype: float64
  - name: name
    dtype: string
  - name: all_names
    dtype: string
  - name: Publisher
    dtype: string
  - name: Country of publication 1
    dtype: string
  - name: all Countries of publication
    dtype: string
  - name: Physical description
    dtype: string
  - name: Language_1
    dtype: string
  - name: Language_2
    dtype: string
  - name: Language_3
    dtype: string
  - name: Language_4
    dtype: string
  - name: multi_language
    dtype: bool
  splits:
  - name: train
    num_bytes: 30447672419
    num_examples: 14011953
  download_size: 16418251509
  dataset_size: 30447672419
- config_name: '1510_1699'
  features:
  - name: record_id
    dtype: string
  - name: date
    dtype: timestamp[s]
  - name: raw_date
    dtype: string
  - name: title
    dtype: string
  - name: place
    dtype: string
  - name: empty_pg
    dtype: bool
  - name: text
    dtype: string
  - name: pg
    dtype: int32
  - name: mean_wc_ocr
    dtype: float32
  - name: std_wc_ocr
    dtype: float64
  - name: name
    dtype: string
  - name: all_names
    dtype: string
  - name: Publisher
    dtype: string
  - name: Country of publication 1
    dtype: string
  - name: all Countries of publication
    dtype: string
  - name: Physical description
    dtype: string
  - name: Language_1
    dtype: string
  - name: Language_2
    dtype: string
  - name: Language_3
    dtype: string
  - name: Language_4
    dtype: string
  - name: multi_language
    dtype: bool
  splits:
  - name: train
    num_bytes: 107654867
    num_examples: 51982
  download_size: 64550390
  dataset_size: 107654867
- config_name: '1700_1799'
  features:
  - name: record_id
    dtype: string
  - name: date
    dtype: timestamp[s]
  - name: raw_date
    dtype: string
  - name: title
    dtype: string
  - name: place
    dtype: string
  - name: empty_pg
    dtype: bool
  - name: text
    dtype: string
  - name: pg
    dtype: int32
  - name: mean_wc_ocr
    dtype: float32
  - name: std_wc_ocr
    dtype: float64
  - name: name
    dtype: string
  - name: all_names
    dtype: string
  - name: Publisher
    dtype: string
  - name: Country of publication 1
    dtype: string
  - name: all Countries of publication
    dtype: string
  - name: Physical description
    dtype: string
  - name: Language_1
    dtype: string
  - name: Language_2
    dtype: string
  - name: Language_3
    dtype: string
  - name: Language_4
    dtype: string
  - name: multi_language
    dtype: bool
  splits:
  - name: train
    num_bytes: 267068570
    num_examples: 178224
  download_size: 143915997
  dataset_size: 267068570
- config_name: 1700s
  features:
  - name: record_id
    dtype: string
  - name: date
    dtype: int32
  - name: raw_date
    dtype: string
  - name: title
    dtype: string
  - name: place
    dtype: string
  - name: empty_pg
    dtype: bool
  - name: text
    dtype: string
  - name: pg
    dtype: int32
  - name: mean_wc_ocr
    dtype: float32
  - name: std_wc_ocr
    dtype: float64
  - name: name
    dtype: string
  - name: all_names
    dtype: string
  - name: Publisher
    dtype: string
  - name: Country of publication 1
    dtype: string
  - name: all Countries of publication
    dtype: string
  - name: Physical description
    dtype: string
  - name: Language_1
    dtype: string
  - name: Language_2
    dtype: string
  - name: Language_3
    dtype: string
  - name: Language_4
    dtype: string
  - name: multi_language
    dtype: bool
  splits:
  - name: train
    num_bytes: 266382657
    num_examples: 178224
  download_size: 95137895
  dataset_size: 266382657
- config_name: '1800_1899'
  features:
  - name: record_id
    dtype: string
  - name: date
    dtype: timestamp[s]
  - name: raw_date
    dtype: string
  - name: title
    dtype: string
  - name: place
    dtype: string
  - name: empty_pg
    dtype: bool
  - name: text
    dtype: string
  - name: pg
    dtype: int32
  - name: mean_wc_ocr
    dtype: float32
  - name: std_wc_ocr
    dtype: float64
  - name: name
    dtype: string
  - name: all_names
    dtype: string
  - name: Publisher
    dtype: string
  - name: Country of publication 1
    dtype: string
  - name: all Countries of publication
    dtype: string
  - name: Physical description
    dtype: string
  - name: Language_1
    dtype: string
  - name: Language_2
    dtype: string
  - name: Language_3
    dtype: string
  - name: Language_4
    dtype: string
  - name: multi_language
    dtype: bool
  splits:
  - name: train
    num_bytes: 30072947637
    num_examples: 13781747
  download_size: 16208795992
  dataset_size: 30072947637
- config_name: 1800s
  features:
  - name: record_id
    dtype: string
  - name: date
    dtype: int32
  - name: raw_date
    dtype: string
  - name: title
    dtype: string
  - name: place
    dtype: string
  - name: empty_pg
    dtype: bool
  - name: text
    dtype: string
  - name: pg
    dtype: int32
  - name: mean_wc_ocr
    dtype: float32
  - name: std_wc_ocr
    dtype: float64
  - name: name
    dtype: string
  - name: all_names
    dtype: string
  - name: Publisher
    dtype: string
  - name: Country of publication 1
    dtype: string
  - name: all Countries of publication
    dtype: string
  - name: Physical description
    dtype: string
  - name: Language_1
    dtype: string
  - name: Language_2
    dtype: string
  - name: Language_3
    dtype: string
  - name: Language_4
    dtype: string
  - name: multi_language
    dtype: bool
  splits:
  - name: train
    num_bytes: 30020434670
    num_examples: 13781747
  download_size: 10348577602
  dataset_size: 30020434670
- config_name: all
  features:
  - name: record_id
    dtype: string
  - name: date
    dtype: int32
  - name: raw_date
    dtype: string
  - name: title
    dtype: string
  - name: place
    dtype: string
  - name: empty_pg
    dtype: bool
  - name: text
    dtype: string
  - name: pg
    dtype: int32
  - name: mean_wc_ocr
    dtype: float32
  - name: std_wc_ocr
    dtype: float64
  - name: name
    dtype: string
  - name: all_names
    dtype: string
  - name: Publisher
    dtype: string
  - name: Country of publication 1
    dtype: string
  - name: all Countries of publication
    dtype: string
  - name: Physical description
    dtype: string
  - name: Language_1
    dtype: string
  - name: Language_2
    dtype: string
  - name: Language_3
    dtype: string
  - name: Language_4
    dtype: string
  - name: multi_language
    dtype: bool
  splits:
  - name: train
    num_bytes: 30394267732
    num_examples: 14011953
  download_size: 10486035662
  dataset_size: 30394267732
configs:
- config_name: '1500_1899'
  data_files:
  - split: train
    path: 1500_1899/train-*
  default: true
- config_name: '1510_1699'
  data_files:
  - split: train
    path: 1510_1699/train-*
- config_name: '1700_1799'
  data_files:
  - split: train
    path: 1700_1799/train-*
- config_name: '1800_1899'
  data_files:
  - split: train
    path: 1800_1899/train-*
---

# Dataset Card for British Library Books

## Table of Contents

- [Dataset Card for British Library Books](#dataset-card-for-British-Library-Books)
  - [Table of Contents](#table-of-contents)
  - [Dataset Description](#dataset-description)
    - [Dataset Summary](#dataset-summary)
    - [Supported Tasks and Leaderboards](#supported-tasks-and-leaderboards)
      - [Language model training](#language-model-training)
      - [Supervised tasks](#supervised-tasks)
    - [Languages](#languages)
      - [Language change](#language-change)
      - [Optical Character Recognition](#optical-character-recognition)
        - [OCR word confidence](#ocr-word-confidence)
  - [Dataset Structure](#dataset-structure)
    - [Data Instances](#data-instances)
    - [Data Fields](#data-fields)
    - [Data Splits](#data-splits)
  - [Dataset Creation](#dataset-creation)
    - [Curation Rationale](#curation-rationale)
    - [Source Data](#source-data)
      - [Initial Data Collection and Normalization](#initial-data-collection-and-normalization)
        - [Date normalization](#date-normalization)
        - [Metadata included](#metadata-included)
      - [Who are the source language producers?](#who-are-the-source-language-producers)
    - [Annotations](#annotations)
      - [Annotation process](#annotation-process)
      - [Who are the annotators?](#who-are-the-annotators)
    - [Personal and Sensitive Information](#personal-and-sensitive-information)
  - [Considerations for Using the Data](#considerations-for-using-the-data)
    - [Social Impact of Dataset](#social-impact-of-dataset)
    - [Discussion of Biases](#discussion-of-biases)
      - [Colonialism](#colonialism)
    - [Other Known Limitations](#other-known-limitations)
  - [Additional Information](#additional-information)
    - [Dataset Curators](#dataset-curators)
    - [Licensing Information](#licensing-information)
    - [Citation Information](#citation-information)
    - [Contributions](#contributions)

## Dataset Description

- **Homepage:** https://www.bl.uk/collection-guides/digitised-printed-books
- **Repository:** https://doi.org/10.21250/db14
- **Paper:**
- **Leaderboard:**
- **Point of Contact:** labs@bl.uk

### Dataset Summary

This dataset consists of books digitised by the British Library in partnership with Microsoft. The dataset includes ~25 million pages of out of copyright texts. The majority of the texts were published in the 18th and 19th Century, but the collection also consists of a smaller number of books from earlier periods. Items within this collection cover a wide range of subject areas, including geography, philosophy, history, poetry and literature and are published in various languages.

While the books are predominately from the 18th and 19th Centuries, there are fewer books from earlier periods. The number of pages in the corpus by decade:

|      | page count |
| ---- | ---------- |
| 1510 | 94         |
| 1520 | 32         |
| 1540 | 184        |
| 1550 | 16         |
| 1580 | 276        |
| 1590 | 540        |
| 1600 | 1117       |
| 1610 | 1132       |
| 1620 | 1856       |
| 1630 | 9274       |
| 1640 | 4232       |
| 1650 | 2944       |
| 1660 | 5858       |
| 1670 | 11415      |
| 1680 | 8348       |
| 1690 | 13756      |
| 1700 | 10160      |
| 1710 | 9556       |
| 1720 | 10314      |
| 1730 | 13282      |
| 1740 | 10778      |
| 1750 | 12001      |
| 1760 | 21415      |
| 1770 | 28490      |
| 1780 | 32676      |
| 1790 | 50014      |
| 1800 | 307806     |
| 1810 | 478008     |
| 1820 | 589419     |
| 1830 | 681212     |
| 1840 | 1113473    |
| 1850 | 1726108    |
| 1860 | 1725407    |
| 1870 | 2069089    |
| 1880 | 2585159    |
| 1890 | 3365031    |

[More Information Needed]

### Supported Tasks and Leaderboards

This collection has been previously used across various digital history and humanities projects since being published.

The dataset consists of text and a range of metadata associated with this text. This metadata includes:

- date of publication
- place of publication
- country of publication
- language
- OCR quality
- physical description of the original physical item

#### Language model training

As a relatively large dataset, `blbooks` provides a source dataset for training language models. The presence of this metadata also offers interesting opportunities to use this dataset as a source for training language models based on:

- specific time-periods
- specific languages
- certain OCR quality thresholds

The above is not an exhaustive list but offer some suggestions of how the dataset can be used to explore topics such as the impact of OCR quality on language models, the ‘transferability’ of language models across time or the impact of training multilingual language models on historical languages.

#### Supervised tasks

Whilst this dataset does not have annotations for a specific NLP task, such as Named Entity Recognition, it does include a wide variety of metadata. This metadata has the potential to be used for training and/or evaluating a variety of supervised tasks predicting this metadata.

### Languages

This dataset consists of books published in several languages. The breakdown of the languages included (at the page level) is:

| Language              | Pages    |
| --------------------- | -------- |
| English               | 10039463 |
| French                | 1442929  |
| German                | 1172793  |
| Spanish               | 286778   |
| Italian               | 214255   |
| Dutch                 | 204759   |
| Russian               | 193347   |
| Danish                | 93366    |
| Hungarian             | 88094    |
| Swedish               | 76225    |
| Polish                | 58901    |
| Greek, Modern (1453-) | 26104    |
| Latin                 | 25611    |
| Portuguese            | 25410    |
| Czech                 | 20160    |
| Bulgarian             | 7891     |
| Finnish               | 5677     |
| Irish                 | 2743     |
| Serbian               | 1975     |
| Romanian              | 1544     |
| Norwegian Nynorsk     | 1398     |
| Croatian              | 1306     |
| Norwegian             | 1227     |
| Icelandic             | 902      |
| Slovak                | 840      |
| Lithuanian            | 714      |
| Welsh                 | 580      |
| Slovenian             | 545      |
| Indonesian            | 418      |
| Cornish               | 223      |

This breakdown was derived from the first language in the associated metadata field. Some books include multiple languages. Some of the languages codes for this data were also derived using computational methods. Therefore, the language fields in the dataset should be treated with some caution (discussed in more detail below).

#### Language change

The publication dates of books in the data cover a broad period of time (1500-1900). For languages in the dataset with broad temporal coverage, significant [language change](https://en.wikipedia.org/wiki/Language_change) might be found. The ability to study this change by taking reasonably large samples of languages covering different time periods is one of the opportunities offered by this dataset. The fact that the text in this dataset was produced via Optical Character Recognition (OCR) causes some challenges for this type of research (see below).

#### Optical Character Recognition

The digitised books in this collection were transformed into machine-readable text using Optical Character Recognition (OCR) software. The text produced via OCR software will usually include some errors. These errors include; mistakes at the character level; for example, an `i` is mistaken for an `l`, at the word level or across significant passages of text.

The books in this dataset can pose some additional challenges for OCR software. OCR errors can stem from:

- the quality of the original printing: printing technology was a developing technology during the time period covered by this corpus; some of the original book text will include misprints, blurred or faded ink that is hard to read
- damage to the page: some of the books will have become damaged over time, this can obscure all or parts of the text on a page
- poor quality scans: scanning books can be challenging; for example, if the book has tight bindings, it can be hard to capture text that has fallen into the [gutter](https://www.abaa.org/glossary/entry/gutter) of the book.
- the language used in the books may differ from the languages OCR software is predominantly trained to recognise.

##### OCR word confidence

Many OCR engines produce some form of confidence score alongside the predicted text. These confidence scores are usually at the character or word level. The word confidence score was given for each word in the original ALTO XML versions of the text in this dataset in this dataset. The OCR confidence scores should be treated with some scepticism. For historical text or in a lower resource language, for example, a low confidence score may be more likely for words not included in a modern dictionary but may be accurate transcriptions of the original text. With that said, the confidence scores do give some sense of the OCR quality.

An example of text with a high (over 90% mean word confidence score):

```
8 direction to the Conduit, round which is a wide open space, and a good broad pavement called the Parade. It commands a pleasant peep of the slopes and terrace throughout its entire length. The street continuing from the Conduit, in the same general direction, was known anciently as Lodborne Lane, and is now named South Street. From the Conduit two other streets, at right angles to these, are Long Street, leading Eastwards, and Half-Moon Street (formerly Lodborne), leading to Westbury, Trendle Street, and the Horsecastles Road.
```

An example of text with a score below 40%:

```
Hannover. Schrift und Druck von Fr. CultniTmn,',
 "LeMNs'utluirui.",
 'ü 8u«llim» M^äalßwi 01de!lop 1<M.',
 'p^dnalmw vom Xr^u/e, lpiti>»**Kmm lie« !»^2!M kleine lii!<! (,«>* ttünee!<»e^ v»n tndzt Lievclum, 1872,
```

The quality of OCR - as measured by mean OCR confidence for a page - across the dataset correlates with other features. A groupby of publication decade and mean word confidence:

| decade | mean_wc_ocr |
| ------ | ----------- |
| 1510   | 0.499151    |
| 1520   | 0.544818    |
| 1540   | 0.511589    |
| 1550   | 0.4505      |
| 1580   | 0.321858    |
| 1590   | 0.461282    |
| 1600   | 0.467318    |
| 1610   | 0.495895    |
| 1620   | 0.501257    |
| 1630   | 0.49766     |
| 1640   | 0.512095    |
| 1650   | 0.528534    |
| 1660   | 0.521014    |
| 1670   | 0.592575    |
| 1680   | 0.583901    |
| 1690   | 0.567202    |
| 1700   | 0.575175    |
| 1710   | 0.61436     |
| 1720   | 0.627725    |
| 1730   | 0.658534    |
| 1740   | 0.64214     |
| 1750   | 0.657357    |
| 1760   | 0.6389      |
| 1770   | 0.651883    |
| 1780   | 0.632326    |
| 1790   | 0.664279    |
| 1800   | 0.682338    |
| 1810   | 0.708915    |
| 1820   | 0.730015    |
| 1830   | 0.730973    |
| 1840   | 0.713886    |
| 1850   | 0.697106    |
| 1860   | 0.696701    |
| 1870   | 0.717233    |
| 1880   | 0.733331    |
| 1890   | 0.762364    |

As might be expected, the earlier periods have lower mean word confidence scores. Again, all of this should be treated with some scepticism, especially as the size of the data grows over time.

As with time, the mean word confidence of the OCR software varies across languages:

| Language_1            | mean_wc_ocr |
| --------------------- | ----------- |
| Croatian              | 0.755565    |
| Welsh                 | 0.7528      |
| Norwegian Nynorsk     | 0.751648    |
| Slovenian             | 0.746007    |
| French                | 0.740772    |
| Finnish               | 0.738032    |
| Czech                 | 0.737849    |
| Hungarian             | 0.736076    |
| Dutch                 | 0.734977    |
| Cornish               | 0.733682    |
| Danish                | 0.733106    |
| English               | 0.733037    |
| Irish                 | 0.732658    |
| Portuguese            | 0.727746    |
| Spanish               | 0.725111    |
| Icelandic             | 0.724427    |
| Italian               | 0.715839    |
| Swedish               | 0.715633    |
| Polish                | 0.715133    |
| Lithuanian            | 0.700003    |
| Bulgarian             | 0.694657    |
| Romanian              | 0.692957    |
| Latin                 | 0.689022    |
| Russian               | 0.685847    |
| Serbian               | 0.674329    |
| Slovak                | 0.66739     |
| Greek, Modern (1453-) | 0.632195    |
| German                | 0.631457    |
| Indonesian            | 0.6155      |
| Norwegian             | 0.597987    |

Again, these numbers should be treated sceptically since some languages appear very infrequently. For example, the above table suggests the mean word confidence for Welsh is relatively high. However, there isn’t much Welsh in the dataset. Therefore, it is unlikely that this data will be particularly useful for training (historic) Welsh language models.

[More Information Needed]

## Dataset Structure

The dataset has a number of configurations relating to the different dates of publication in the underlying data:

- `1500_1899`: this configuration covers all years
- `1800_1899`: this configuration covers the years between 1800 and 1899
- `1700_1799`: this configuration covers the years between 1700 and 1799
- `1510_1699`: this configuration covers the years between 1510 and 1699

### Configuration option

All of the configurations have an optional keyword argument `skip_empty_pages` which is set to `True` by default. The underlying dataset includes some pages where there is no text. This could either be because the underlying book page didn't have any text or the OCR software failed to detect this text.

For many uses of this dataset it doesn't make sense to include empty pages so these are skipped by default. However, for some uses you may prefer to retain a representation of the data that includes these empty pages. Passing `skip_empty_pages=False` when loading the dataset will enable this option.

### Data Instances

An example data instance:

```python
{'Country of publication 1': 'England',
'Language_1': 'English',
'Language_2': None,
'Language_3': None,
'Language_4': None,
'Physical description': None,
'Publisher': None,
'all Countries of publication': 'England',
'all names': 'Settle, Elkanah [person]',
'date': 1689,
'empty_pg': True,
'mean_wc_ocr': 0.0,
'multi_language': False,
'name': 'Settle, Elkanah',
'pg': 1,
'place': 'London',
'raw_date': '1689',
'record_id': '001876770',
'std_wc_ocr': 0.0,
'text': None,
‘title’: ‘The Female Prelate: being the history and the life and death of Pope Joan. A tragedy [in five acts and in verse] . Written by a Person of Quality [i.e. Elkanah Settle]’}

```

Each instance in the dataset represents a single page from an original digitised book.

### Data Fields

Included in this dataset are:

| Field                        | Data Type | Description                                                                                                   |
| ---------------------------- | --------- | ------------------------------------------------------------------------------------------------------------- |
| record_id                    | string    | British Library ID for the item                                                                               |
| date                         | int       | parsed/normalised year for the item. i.e. 1850                                                                |
| raw_date                     | string    | the original raw date for an item i.e. 1850-                                                                  |
| title                        | string    | title of the book                                                                                             |
| place                        | string    | Place of publication, i.e. London                                                                             |
| empty_pg                     | bool      | whether page contains text                                                                                    |
| text                         | string    | OCR generated text for a page                                                                                 |
| pg                           | int       | page in original book the instance refers to                                                                  |
| mean_wc_ocr                  | float     | mean word confidence values for the page                                                                      |
| std_wc_ocr                   | float     | standard deviation of the word confidence values for the page                                                 |
| name                         | string    | name associated with the item (usually author)                                                                |
| all names                    | string    | all names associated with a publication                                                                       |
| Publisher                    | string    | publisher of the book                                                                                         |
| Country of publication 1     | string    | first country associated with publication                                                                     |
| all Countries of publication | string    | all countries associated with a publication                                                                   |
| Physical description         | string    | physical description of the item (size). This requires some normalisation before use and isn’t always present |
| Language_1                   | string    | first language associated with the book, this is usually present                                              |
| Language_2                   | string    |                                                                                                               |
| Language_3                   | string    |                                                                                                               |
| Language_4                   | string    |                                                                                                               |
| multi_language               | bool      |                                                                                                               |

Some of these fields are not populated a large proportion of the time. You can get some sense of this from this [Pandas Profiling](https://github.com/pandas-profiling/pandas-profiling) [report](https://davanstrien.github.io/BL-datasets-pandas-profile-reports/pandas_profile_report_MS_digitised_books_2021-01-09.html)

The majority of these fields relate to metadata about the books. Most of these fields were created by staff working for the British Library. The notable exception is the “Languages” fields that have sometimes been determined using computational methods. This work is reported in more detail in [Automated Language Identification of Bibliographic Resources](https://doi.org/10.1080/01639374.2019.1700201). It is important to note that metadata is neither perfect nor static. The metadata associated with this book was generated based on export from the British Library catalogue in 2021.

[More Information Needed]

### Data Splits

This dataset contains a single split `train`.

## Dataset Creation

**Note** this section is a work in progress.

### Curation Rationale

The books in this collection were digitised as part of a project partnership between the British Library and Microsoft. [Mass digitisation](https://en.wikipedia.org/wiki/Category:Mass_digitization), i.e. projects intending to quickly digitise large volumes of materials shape the selection of materials to include in several ways. Some considerations which are often involved in the decision of whether to include items for digitisation include (but are not limited to):

- copyright status
- preservation needs
- the size of an item, very large and very small items are often hard to digitise quickly

These criteria can have knock-on effects on the makeup of a collection. For example, systematically excluding large books may result in some types of book content not being digitised. Large volumes are likely to be correlated to content to at least some extent, so excluding them from digitisation will mean that material is underrepresented. Similarly, copyright status is often (but not only) determined by publication date. This can often lead to a rapid fall in the number of items in a collection after a certain cut-off date.

All of the above is largely to make clear that this collection was not curated to create a representative sample of the British Library’s holdings. Some material will be over-represented, and others under-represented. Similarly, the collection should not be considered a representative sample of what was published across the period covered by the dataset (nor that the relative proportions of the data for each time period represent a proportional sample of publications from that period). Finally, and this probably does not need stating, the language included in the text should not be considered representative of either written or spoken language(s) from that time period.

[More Information Needed]

### Source Data

The source data (physical items) includes a variety of resources (predominantly monographs) held by the [British Library](bl.uk/](https://bl.uk/). The British Library is a [Legal Deposit](https://www.bl.uk/legal-deposit/about-legal-deposit) library. “Legal deposit requires publishers to provide a copy of every work they publish in the UK to the British Library. It’s existed in English law since 1662.” [source](https://www.bl.uk/legal-deposit/about-legal-deposit).

The source data for this version of the data is derived from the original ALTO XML files and a recent metadata export #TODO add links

[More Information Needed]

#### Initial Data Collection and Normalization

This version of the dataset was created using the original ALTO XML files and, where a match was found, updating the metadata associated with that item with more recent metadata using an export from the British Library catalogue. The process of creating this new dataset is documented here #TODO add link.

There are a few decisions made in the above processing steps worth highlighting in particular:

##### Date normalization

The metadata around date of publication for an item is not always exact. It often is represented as a date range e.g. `1850-1860`. The `date` field above takes steps to normalise this date to a single integer value. In most cases, this is taking the mean of the values associated with the item. The `raw_date` field includes the unprocessed date string.

##### Metadata included

The metadata associated with each item includes most of the fields available via the ALTO XML. However, the data doesn’t include some metadata fields from the metadata export file. The reason fields were excluded because they are frequently not populated. A cut off of 50% was chosen, i.e. values from the metadata which are missing above 50% of the time were not included. This is slightly arbitrary, but since the aim of this version of the data was to support computational research using the collection it was felt that these fields with frequent missing values would be less valuable.

#### Who are the source language producers?

[More Information Needed]

### Annotations

This dataset does not include annotations as usually understood in the context of NLP. The data does include metadata associated with the books.

#### Annotation process

[More Information Needed]

#### Who are the annotators?

[More Information Needed]

### Personal and Sensitive Information

[More Information Needed]

## Considerations for Using the Data

There a range of considerations around using the data. These include the representativeness of the dataset, the OCR quality and the language used. Depending on your use case, these may be more or less important. For example, the impact of OCR quality on downstream tasks will depend on the target task. It may also be possible to mitigate this negative impact from OCR through tokenizer choice, Language Model training objectives, oversampling high-quality OCR, etc.

[More Information Needed]

### Social Impact of Dataset

[More Information Needed]

### Discussion of Biases

The text in this collection is derived from historical text. As a result, the text will reflect this time period's social beliefs and attitudes. The books include both fiction and non-fiction books.

Examples of book titles that appear in the data (these are randomly sampled from all titles):

- ‘Rhymes and Dreams, Legends of Pendle Forest, and other poems’,
- “Précis of Information concerning the Zulu Country, with a map. Prepared in the Intelligence Branch of the Quarter-Master-General’s Department, Horse Guards, War Office, etc”,
- ‘The fan. A poem’,
- ‘Grif; a story of Australian Life’,
- ‘Calypso; a masque: in three acts, etc’,
- ‘Tales Uncle told [With illustrative woodcuts.]’,
- 'Questings',
- 'Home Life on an Ostrich Farm. With ... illustrations’,
- ‘Bulgarya i Bulgarowie’,
- 'Εἰς τα βαθη της Ἀφρικης [In darkest Africa.] ... Μεταφρασις Γεωρ. Σ. Βουτσινα, etc',
- ‘The Corsair, a tale’,
  ‘Poems ... With notes [With a portrait.]’,
- ‘Report of the Librarian for the year 1898 (1899, 1901, 1909)’,
- “The World of Thought. A novel. By the author of ‘Before I began to speak.’”,
- 'Amleto; tragedia ... recata in versi italiani da M. Leoni, etc']

While using titles alone is insufficient to integrate bias in this collection, it gives some insight into the topics covered by books. Further, the tiles highlight some particular types of bias we might find in the collection. This should in no way be considered an exhaustive list.

#### Colonialism

Even in the above random sample of titles examples of colonial attitudes, we can see examples of titles. We can try and interrogate this further by searching for the name of places that were part of the British Empire when many of these books were published.

Searching for the string `India` in the titles and randomly sampling 10 titles returns:

- “Travels in India in the Seventeenth Century: by Sir Thomas Roe and Dr. John Fryer. Reprinted from the ‘Calcutta Weekly Englishman.’”,
- ‘A Winter in India and Malaysia among the Methodist Missions’,
- “The Tourist’s Guide to all the principal stations on the railways of Northern India [By W. W.] ... Fifth edition”,
- ‘Records of Sport and Military Life in Western India ... With an introduction by ... G. B. Malleson’,
- "Lakhmi, the Rájpút's Bride. A tale of Gujarát in Western India [A poem.]”,
- ‘The West India Commonplace Book: compiled from parliamentary and official documents; shewing the interest of Great Britain in its Sugar Colonies’,
- “From Tonkin to India : by the sources of the Irawadi, January’ 95-January ’96”,
- ‘Case of the Ameers of Sinde : speeches of Mr. John Sullivan, and Captain William Eastwick, at a special court held at the India House, ... 26th January, 1844’,
- ‘The Andaman Islands; their colonisation, etc. A correspondence addressed to the India Office’,
- ‘Ancient India as described by Ptolemy; being a translation of the chapters which describe India and Eastern Asia in the treatise on Geography written by Klaudios Ptolemaios ... with introduction, commentary, map of India according to Ptolemy, and ... index, by J. W. McCrindle’]

Searching form the string `Africa` in the titles and randomly sampling 10 titles returns:

- ['De Benguella ás Terras de Iácca. Descripção de uma viagem na Africa Central e Occidental ... Expedição organisada nos annos de 1877-1880. Edição illustrada',
- ‘To the New Geographical Society of Edinburgh [An address on Africa by H. M. Stanley.]’,
- ‘Diamonds and Gold in South Africa ... With maps, etc’,
- ‘Missionary Travels and Researches in South Africa ... With notes by F. S. Arnot. With map and illustrations. New edition’,
- ‘A Narrative of a Visit to the Mauritius and South Africa ... Illustrated by two maps, sixteen etchings and twenty-eight wood-cuts’,
- ‘Side Lights on South Africa ... With a map, etc’,
- ‘My Second Journey through Equatorial Africa ... in ... 1886 and 1887 ... Translated ... by M. J. A. Bergmann. With a map ... and ... illustrations, etc’,
- ‘Missionary Travels and Researches in South Africa ... With portrait and fullpage illustrations’,
- ‘[African sketches.] Narrative of a residence in South Africa ... A new edition. To which is prefixed a biographical sketch of the author by J. Conder’,
- ‘Lake Ngami; or, Explorations and discoveries during four years wandering in the wilds of South Western Africa ... With a map, and numerous illustrations, etc’]

[More Information Needed]

### Other Known Limitations

[More Information Needed]

## Additional Information

### Dataset Curators

[More Information Needed]

### Licensing Information

The books are licensed under the [CC Public Domain Mark 1.0](https://creativecommons.org/publicdomain/mark/1.0/) license.

### Citation Information

```bibtext
@misc{bBritishLibraryBooks2021,
  author = {British Library Labs},
  title = {Digitised Books. c. 1510 - c. 1900. JSONL (OCR derived text + metadata)},
  year = {2021},
  publisher = {British Library},
  howpublished={https://doi.org/10.23636/r7w6-zy15}

```

### Contributions

Thanks to [@davanstrien](https://github.com/davanstrien) for adding this dataset.