ocr-verify

corpus.pdf

Witness reading (Tesseract) vs Marker (balanced VLM mode, real run 2026-08-16) · 24 pages checked · rendered at 200 DPI

PDF study/corpus/corpus.pdf AI output study/marker_out/corpus/corpus.md

12
Pages flagged
of 24
72
Unsupported words
of 1,352 emitted
5.33%
Divergence
on 21 verified pages
Unsupported text2Dropped text16Wholesale disagreement2Unverifiable page1

How to read this

Tesseract read every page independently as a witness. It is not the ground truth — it is worse than the AI engine at almost everything. It has one property the AI engine lacks: it does not invent words. Each finding below is a place the two readings diverge, shown with the crop of the scan it came from.

Text merely moved on the page — reordered columns, floated captions, table cells read in a different sequence — is not reported: a word counts as unsupported only when it is absent from the witness reading of the whole page. Words below 40% witness confidence are excluded from the comparison entirely. Pages where the witness itself struggled are labelled, and their findings are hedged.

Flagged pages

Page 21

divergence 37.9% 153 AI words 104 witness words ink 2.13%
Unsupported text 1.00 48 tokens
Scan region for this finding
Scan — crop at 192,817

AI engine read

conditions of considerable hardship is evident throughout the resident observers. The summary telegrams tension in the commission striping the subply vessel tourists off the shorts in each season and only was the subply vessel tourists off the shorts in each season and only was the subply vessel tourists off the shorts in each season and only

Witness read

returns.

Unsupported text 0.75 10 tokens
Scan region for this finding
Scan — crop at 193,345

AI engine read

the coastal survey achieved the greater part of the summer of the summer of the coastal stations and particularly the fourteen proposed stations, and tidal series of

Witness read

its stated objectives. Positions were fixed for eleven of

Dropped text 0.52 8 tokens
Scan region for this finding
Scan — crop at 193,345

AI engine read

(nothing)

Witness read

its stated objectives. Positions were fixed for eleven

Page 1

divergence 0.0% 85 AI words 124 witness words ink 2.55%
Dropped text 0.90 34 tokens
Scan region for this finding
Scan — crop at 193,766

AI engine read

(nothing)

Witness read

Readings from the third party have not survived. The field notebooks were lost when the supply vessel foundered off the shoals in early September, and only the summary telegrams remain in the commission archive.

Dropped text 0.40 5 tokens
Scan region for this finding
Scan — crop at 193,204

AI engine read

(nothing)

Witness read

The Survey of Coastal Stations

Page 9

divergence 0.0% 78 AI words 115 witness words ink 1.52%
Dropped text 0.90 33 tokens
Scan region for this finding
Scan — crop at 192,719

AI engine read

(nothing)

Witness read

A comparison of the winter series with the corresponding series from the preceding year shows agreement within two hundredths of a foot for the mean water level, which the commission regarded as satisfactory.

Dropped text 0.36 4 tokens
Scan region for this finding
Scan — crop at 193,204

AI engine read

(nothing)

Witness read

Observations of the Tide

Page 10

divergence 0.0% 78 AI words 115 witness words ink 0.29%
Dropped text 0.90 33 tokens
Scan region for this finding
Scan — crop at 192,719

AI engine read

(nothing)

Witness read

A comparison of the winter series with the corresponding series from the preceding year shows agreement within two hundredths of a foot for the mean water level, which the commission regarded as satisfactory.

Dropped text 0.36 4 tokens
Scan region for this finding
Scan — crop at 193,204

AI engine read

(nothing)

Witness read

Observations of the Tide

Page 11

divergence 0.0% 0 AI words 115 witness words ink 0.00%
Dropped text 0.90 115 tokens
Scan region for this finding
Scan — crop at 192,204

AI engine read

(nothing)

Witness read

Observations of the Tide Tidal observations at Station Marlow were continued through the winter without interruption. The gauge was of the float pattern, housed in a timber well sunk four feet below the lowest recorded water. Readings were taken hourly by the resident observer and transcribed each evening. The self-registering apparatus failed twice during December, on both occasions owing to the freezing of the float chamber. Manual readings were substituted for the affected intervals and are marked accordingly in the published tables. A comparison of the winter series with the corresponding series from the preceding year shows agreement within two hundredths of a foot for the mean water level, which the commission regarded as satisfactory.

Page 16

divergence 0.0% 85 AI words 124 witness words ink 2.64%
Dropped text 0.90 34 tokens
Scan region for this finding
Scan — crop at 192,766

AI engine read

(nothing)

Witness read

Readings from the third party have not survived. The field notebooks were lost when the supply vessel foundered off the shoals in early September, and only the summary telegrams remain in the commission archive.

Dropped text 0.40 5 tokens
Scan region for this finding
Scan — crop at 192,204

AI engine read

(nothing)

Witness read

The Survey of Coastal Stations

Page 17

divergence 0.0% 85 AI words 124 witness words ink 2.73%
Dropped text 0.90 34 tokens
Scan region for this finding
Scan — crop at 192,766

AI engine read

(nothing)

Witness read

Readings from the third party have not survived. The field notebooks were lost when the supply vessel foundered off the shoals in early September, and only the summary telegrams remain in the commission archive.

Dropped text 0.40 5 tokens
Scan region for this finding
Scan — crop at 192,204

AI engine read

(nothing)

Witness read

The Survey of Coastal Stations

Page 18

divergence 0.0% 78 AI words 115 witness words ink 2.42%
Dropped text 0.90 33 tokens
Scan region for this finding
Scan — crop at 181,709

AI engine read

(nothing)

Witness read

A comparison of the winter series with the corresponding series from the preceding year shows agreement within two hundredths of a foot for the mean water level, which the commission regarded as satisfactory.

Dropped text 0.36 4 tokens
Scan region for this finding
Scan — crop at 163,217

AI engine read

(nothing)

Witness read

Observations of the Tide

Page 22

divergence 2.4% 85 AI words 121 witness words ink 1.39%
Dropped text 0.90 33 tokens
Scan region for this finding
Scan — crop at 184,757

AI engine read

(nothing)

Witness read

Readings from the third party have not survived. The field notebooks were lost when the supply vessel foundered off the shoals in early September, and only the telegrams remain in the commission archive.

Dropped text 0.40 5 tokens
Scan region for this finding
Scan — crop at 169,213

AI engine read

(nothing)

Witness read

The Survey of Coastal Stations

Page 19

divergence 24.4% 78 AI words 88 witness words ink 2.43% excluded from gate
Wholesale disagreement 0.50 48 tokens
Scan region for this finding
Scan — full page

AI engine read

continued winter housed in timber recorded taken hourly by evening. The self-registering readings were intervals accordingly in published tables.

Witness read

e Tide of th nter ed wi ng continu ded Readin: d observatio recor’ s istering W self-reg M interv als ace preceding year shows a water level, which

19 of 78 AI words lack witness support and 29 of 88 witness words lack AI support, and 48% of the unmatched witness words are short shreds — the witness likely could not handle this page. Review the page image rather than trusting either reading.

Page 23

divergence 43.6% 78 AI words 77 witness words ink 0.00% excluded from gate
Wholesale disagreement 0.50 67 tokens
Scan region for this finding
Scan — full page

AI engine read

at were continued through without interruption. gange pattern, in lowest recorded taken observer transcribed self-registering failed December, on occasions owing to float chamber. readings were substituted intervals and are marked accordingly in published tables.

Witness read

Tide of ma ine oto bet oat ured ane im of with the sence from the Preceding year shows two hundredths of a foot for the meat water level, which Mie regarded os

34 of 78 AI words lack witness support and 33 of 77 witness words lack AI support, and 55% of the unmatched witness words are short shreds — the witness likely could not handle this page. Review the page image rather than trusting either reading.

Page 15

divergence 0.0% 104 AI words 0 witness words ink 2.50% witness quality: blind excluded from gate
Unverifiable page 0.15 104 tokens
Scan region for this finding
Scan — full page

AI engine read

Conclusions of the Commission The commission concludes that the coastal survey achieved the greater part of its stated objectives. Positions were fixed for eleven of the fourteen proposed stations, and tidal series of at least six months were obtained at seven. The loss of the third party's notebooks is regretted. The commission recommends that duplicate records be transmitted by post …

Witness read

(the witness read nothing here)

Ink coverage is 2.50%. The witness read only 0 usable words against the AI engine's 104. Nothing on this page was verified.

Every page

PageDivergenceAI wordsWitness words UnsupportedDroppedInkWitness In gate Findings
10.0%851240392.55%okyes2
20.0%9494001.83%okyes0
30.0%00000.00%okyes0
40.0%00000.23%okyes0
50.0%00000.00%okyes0
60.0%00000.00%okyes0
70.0%00000.00%okyes0
80.0%00000.36%okyes0
90.0%781150371.52%okyes2
100.0%781150370.29%okyes2
110.0%011501150.00%okyes1
120.0%111111002.58%okyes0
139.9%1111091193.22%okyes0
140.0%104104002.18%okyes0
150.0%1040002.50%blindno1
160.0%851240392.64%okyes2
170.0%851240392.73%okyes2
180.0%781150372.42%okyes2
1924.4%788819292.43%okno1
200.0%111111002.95%okyes0
2137.9%1531045892.13%okyes3
222.4%851212381.39%okyes2
2343.6%787734330.00%okno1
241.1%9494111.12%okyes0