chi-square test

経済協力開発機構は，世界２４か国の大人を対象に基本的計算能力のテストを実施し，アメリカは２２番目という結果に終わりました。

HERE’S an apparent paradox: Most Americans have taken high school mathematics, including geometry and algebra, yet a national survey found that 82 percent of adults could not compute the cost of a carpet when told its dimensions and square-yard price. The Organization for Economic Cooperation and Development recently tested adults in 24 countries on basic “numeracy” skills. Typical questions involved odometer readings and produce sell-by tags. The United States ended an embarrassing 22nd, behind Estonia and Cyprus. We should be doing better. Is more mathematics the answer?

Something similar occurred when the Carnegie Foundation for the Advancement of Teaching created a statistics course for 19 community colleges in 2012. It was advertised as an alternative to remedial algebra, with its sadistic attrition rates. In Statways, as it was called, here is some of what students were asked to master: chi-square test for homogeneity in two-way tables, line multiple representation of exponential models. Even with small classes and extra support, almost half of the students got D’s or F’s or dropped the class.

http://www.nytimes.com/2016/02/28/opinion/sunday/the-wrong-way-to-teach-math.html?emc=edit_th_20160228&nl=todaysheadlines&nlid=61645515&_r=1

今回取り上げる表現は，“chi-square test”です。“test”があることから，何かテストや検定に関係することが予測できます。では，どのような意味があるのか。“chi”には，『ジーニアス英和辞典』（大修館書店）によると，「キー，カイ（ギリシアアルファベットの第２２字〈x，X〉）」と記載されていました。“square”には，「正方形」の他に「二乗」といった意味があります。これらの表現と“test”を組み合わさると，「カイ二乗検定」となります。カイ二乗検定とは，「統計学で，カイ自乗分布を用いる一連の仮説検定の方法」です。(Nao)