"In the Unverified Digital World, Are Journalists and Bloggers Equal?", Slashdot 3/24/2014:
As the source of news moves increasingly away from traditional channels to the millions of people carrying mobile phones and sharing commentary, photos and video on social networks, the distinction between journalists and bloggers has become increasingly blurred. Making sense of this type of information has been as much a challenge for journalists as it has bloggers. Journalists, like bloggers, have had to learn new skills in working in this environment. Highlighting this has been the release of the Verification Handbook which attempts to educate journalists in how to process user-generated content in the form of videos or images acknowledging that much of the reporting about situations, especially emergency ones, comes from the public. The techniques outlined are accessible to anyone reporting on a story, adding to the eroding gap between bloggers and journalists.
WCS, who sent this in, points out that it involves the same sort of "positive-negative backflip" that may play a role in the hard to understate examples, and perhaps in some of the other misnegation cases.
Certainly "adding to the gap", in this passage, means to make the gap smaller — apparently by way of adding to its erosion.
It may also be instructive to compre cases of the filling a much-needed gap type. Roger Koenker has proposed a "Society for the Preservation of Gaps in the Literature", and cites Allyn Jackson, "Chinese Acrobatics, an Old-Time Brewery, and the 'Much Needed Gap': The Life of Mathematical Reviews", Notices of the AMS 1997, which includes this origin story:
Snide reviews form part of the folklore of Mathematical Reviews. The most famous one is as sublimely succinct as it is damning: “This paper fills a much needed gap in the literature.”
Though well known, this sentence never actually appeared in a review. Its origins were explained in a letter from Lee Neuwirth to Gerald Janusz, who looked into the matter when he served as executive editor from 1990 to 1992. Around 1960, when he was an instructor at Princeton, Neuwirth began a review of an article by Hale Trotter with the infamous sentence. Unaware of what he had done, Neuwirth showed the review to his colleague Ralph Fox, who “roared with laughter.” Fox rewrote the review, and it eventually appeared, without the sentence, under Fox’s name (MR 24 (1962), 683, number A3645). It appears that Fox told the story about the sentence to others, but in the telling he left out the names of Neuwirth and Trotter.
Lee Neuwirth may have independently invented the error, but he was not its first creator. Thus we have the "Forty-fourth Annual Report of the [NY] State Museum of Natural History", 12/3/1890:
In the palaeontological department the Rust collection of fossils, from the Trenton and Hudson river groups, near Trenton Falls, is preeminent. It fills a much needed gap, particularly in its magnificent specimens of trilobites of the Trenton epoch.
Or the Review, of Allan McLane Hamilton, A System of Legal Medicine, in The University of Pennsylvania Medical Bulletin, 1895:
There has been no exhaustive book on this subject in this country, and Dr. Hamilton's system fills a much-needed gap.
And there are many other examples of prior art, or perhaps we should say spontaneous generation.
Professor Koenker also quotes John Maynard Keynes, in his Treatise on Probability, arguing (in effect) that it would be better to form a Society for the Creation of Gaps in the Literature:
I have not read all these books myself, but I have read more of them than it would be good for any one to read again. There are here enumerated many dead treatises and ghostly memoirs. The list is too long, and I have not always successfully resisted the impulse to add to it in the spirit of a collector. There are not above a hundred of these which it would be worth while to preserve,–if only it were securely ascertained which these hundred are. At present a bibliographer takes pride in numerous entries; but he would be a more useful fellow, and the labours of research would be lightened, if he could practise deletion and bring into existence an accredited Index Expurgatorius. But this can only be accomplished by the slow mills of the collective judgement of the learned; and I have already indicated my own favorite authors in copious footnotes to the main body of the text.