A paragraph is the default unit of a running text, and usually provides a single thought or narrative.
“Graphic was published on Saturdays, and ‘Place aux Dames’ appeared every week, typically in the middle of the newspaper and on one page; often, her paragraphs make up the top and bottom third, with illustrations of some recent event, sometimes a sporting event, comprising the middle third; sometimes her paragraphs take up the left two-thirds of the page, with unrelated illustrations on the right.” [Cogdill, 182-83]
“In this, it is ‘illustrative,’ and one need go no further than the opening paragraphs in order to understand just what the instruction might be: in the midst of life we are in death’.” [Fieldberg, 14]
“For one thing, most of the short paragraphs of news, which are so conspicuous in the folio edition, were not reprinted.” [Bateson, 155]
“One of them is a proof sheet of the leader published on 18 July 1730 in Craftsman No. 218 (reprinted as No. 211 and marked ‘A’), with corrections in Amhurst’s hand and two manuscript sheets corresponding to part of the printed leader, together with a separate ‘Foreign Affairs’ paragraph.“ [Lockwood, 95]
“A report of a meeting of ministers at Ocean Grove, for example, reflects in the lead paragraph the correspondent’s tongue-in-cheek attitude toward the guardians of moral righteousness.” [Kwiat, 104]
“The correct separation of the text into paragraphs is important for many reasons, especially for any kind of Natural Language Processing where tree- and part-of-speech taggers are used. They will in many cases rely on the correct start and end of sentences.” [Europeana Newspapers, 48]