In statistics , "ranking" refers to the data transformation in which numerical or ordinal values are replaced by their rank when the data are sorted. For example, the numerical data , , , are observed, the ranks of these data items would be 2, 3, 1 and 4 respectively. For example, the ordinal data hot, cold, warm would be replaced by 3, 1, 2. In these examples, the ranks are assigned to values in ascending order. (In some other cases, descending ranks are used.) Ranks are related to the indexed list of order statistics , which consists of the original dataset rearranged into ascending order.
Old English ranc "proud, overbearing, showy," from Proto-Germanic *rankaz (cf. Danish rank "right, upright," German rank "slender," Old Norse rakkr "straight, erect"), perhaps from PIE *reg- "to stretch, straighten" (see right (adj.)). In reference to plant growth, "vigorous, luxuriant, abundant, copious" it is recorded from . Related: Rankly ; rankness .
Sense evolved in Middle English to "large and coarse" (), then, via notion of "excessive and unpleasant," to "corrupt, loathsome, foul" (mid-14c.), perhaps from influence of Middle French rance "rancid." In 17c. also "lewd, lustful."
Much used 16c. as a pejorative intensive (cf. rank folly ). This is possibly the source of the verb meaning "to reveal another's guilt" (1929, underworld slang), and that of "to harass, abuse," 1934, . black dialect, though this also may be from the role of the activity in establishing social hierarchy (from rank (n.)).