Statistics and figures

Two languages named the same data point and chose two different pictures. French calls it une valeur aberrante, and the adjective comes from Latin aberrare, built out of ab, away, and errare, to wander — the same errare behind « error » and « erratic » and behind French errer, to roam. The French name therefore says what the value did: it strayed away from where the others are. English named it by position instead. An « outlier » is what lies out, outside the rest, and the word had that plain spatial sense — a piece detached from the mass it belongs to — long before it reached a scatter plot. English does own the other root, « aberration », but has parked it in optics, where a lens shows « chromatic aberration », and in conduct, where a lapse is « an aberration »; it never means a stray number. So the two terms are less translations of one another than two verdicts: the French one treats the value as a wanderer, the English one as a neighbour standing apart. French will also say une donnée atypique, which is milder and accuses the value of nothing.