Science and research

The fourteenth entry is a mediana, and its own example sentence — a mediana diz outra coisa que a média — names a confusion that English built into its vocabulary centuries before anybody counted anything with it. Late Latin had medianus, the one in the middle, formed on medius. It reached us the long way round, through Old French, worn down at every step until it arrived as « mean » — which is why « mean » in a statistics paper is the arithmetic average and nothing else. Much later, when scientific English needed a name for the value with half the observations on either side of it, it went back to the same Latin word and borrowed it a second time, untouched, as « median ». The two columns facing each other in an English table are therefore one word taken twice, and they hold two different numbers. Portuguese did not split it that way. A mediana is the direct heir of medianus and means the middle observation; the average is a média, from media. Where we spent one root on both figures, Portuguese spent two.