Block · one region of the page, as the scanner read it. It may hold a whole story, part of one, several, or an advertisement; stitching blocks into articles is the next step. Text is supplied OCR.
Page 4 · column 4 of 7 · from the scan, no model involved

may certainly be an element, but the composite index is far more complicated than that.
I would also like to mention that numerous individuals over the years as well as the Headwaters organization have been working very hard
95.7%