Notes

Accuracy of OCR and overProof is measured in comparison with the human corrections. We know human corrections in this sample are incomplete, and themselves contain errors, but they are the best we could find automatically from the NLA newspapers corpus, tagged as completely corrected then further filtered to those with at least 3 corrections, at least 40% of lines corrected and lowest third percentage of non-dictionary words.
Accuracy is measured by a separate process from that used to colour words in this output: the colouring process is heuristic, and not completely accurate.
Colour legend:
Text - OCR text corrected by human and/or overProof
Text - human and/or overProof corrections
Text - discrepencies between human and/or overProof
Text - human corrections not applied by overProof
Identified overProof corrections are calculated by the statistical calculation process, and shows those words changed by overProof which ALSO match human corrections. As human corrections are often wrong and incomplete, so too is this list.
Identified overProof non-corrections are calculated by the statistical calculation process, and shows those words in the overProof output which DO NOT MATCH human corrections. As human corrections are often wrong and incomplete, so too is this list. Words marked as [**VANDALISED] are those which have been changed by overProof but not by the human correction; as before, a missed human correction will be (incorrectly) classified as vandalisation by overProof.
Searchability of unique words refers to the distinct words in an article, and how many are present before and after correction. It is measure of how many of the words within an article could be used to find the article using a search engine.
Weighted Words refers to a calculation in which common words count for little (a fraction of a word) and unusual words count for more, in proportion to the log of the inverse of their frequency in the corpus. It may be an indicator of how well distinctive words in an article can be searched before and after correction.

Article ID 2182175, Article, FOR LONDON., page 1 1823-09-04, The Sydney Gazette and New South Wales Advertiser (NSW : 1803 - 1842), 149 words, 7 corrections

Identified overProof corrections	/FIRST/CLASS\|FIRSTCLASS DESCRIPTION SUPERIOR
Identified overProof non-corrections	COMMODORE COMMANDED ACCOMMODATIONS

	Word count	OCR accuracy %	overProof accuracy %	Errors corrected %
All Words	116	94.0	96.6	42.9
Searchability of unique words	81	92.6	96.3	50.0
Weighted Words		93.6	96.8	50.0

NLA Trial Articles from 1823

Article ID 2182175, Article, FOR LONDON., page 1 1823-09-04, The Sydney Gazette and New South Wales Advertiser (NSW : 1803 - 1842), 149 words, 7 corrections

Accumulated stats for 1 articles from year 1823

Raw OCR	Human Corrected	overProof Corrected
FOR LONDON.	FOR LONDON.	FOR LONDON.
rpWE Beautiful F-rst-class Teak-built Ship COM-.	THE Beautiful First-class Teak-built Ship COM-	THE Beautiful First-class Teak-built Ship COM-.
i MODORE HAYES, Burthen 700 Tons, com-, <	MODORE HAYES, Burthen 700 Tons, com-	i MODORE HAYES, Burthen 700 Tons, com-, <
manded by Captain L. W MONCRIEF (late of the	manded by Captain L. W MONCRIEF (late of the	manded by Captain L. W MONCRIEF (late of the
Shipley ), will be ready to receive Freight, for London, ?	Shipley), will be ready to receive Freight, for London,	Shipley ), will be ready to receive Freight, for London, by
by the Commencement of October. < » ,25 f	by the Commencement of October.	the Commencement of October. < a 25 of
The Whole of the between Decks of this fine Vessels*. -	The Whole of the between Decks of this fine Vessels	The Whole of the between Decks of this fine Vessels. -
will be appropriated for Passengers j and the Accom-n4	will be appropriated for Passengers ; and the	will be appropriated for Passengers ; and the Account
modations are of that snperiQr,dfcScription, as to ren-	Accommodations are of that superior description, as	modations are of that superior, dEScription, as to render
der the present a most desirable Opportunity of	to render the present a most desirable Opportunity	the present a most desirable Opportunity of
embarking for the Mother Country.	of embarking for the Mother Country.	embarking for the Mother Country.
Captain M. will shortly have the Pleasure of offer-	Captain M. will shortly have the Pleasure of offer-	Captain M. will shortly have the Pleasure of offer-
ing his personal Respects to those Gentlemen who are*" -	ing his personal Respects to those Gentlemen who are	ing his personal Respects to those Gentlemen who are" -
usually Shippers of Colonial Produce, and from whom- l	usually Shippers of Colonial Produce, and from whom	usually Shippers of Colonial Produce, and from whom- l
he has already received so many Favors of the same- .	he has already received so many Favors of the same	he has already received so many Favors of the same.
Nature. -, , ?> < < < » > 't *	Nature.	Nature. e, < a 't s
For Information, relative to Freight or Passage, ap«	For Information, relative to Freight or Passage, ap-	For Information, relative to Freight or Passage, apply
ply to BERRY and WOLLSTONECRAFT.	ply to BERRY and WOLLSTONECRAFT.	to BERRY and WOLLSTONECRAFT.