Pearson"s chi-square (χ2) test is the best-known of several chi-square tests – statistical procedures whose results are evaluated by reference to the chi-square distribution. Its properties were first investigated by Karl Pearson. In contexts where it is important to make a distinction between the test statistic and its distribution, names similar to Pearson Χ-squared test or statistic are used.
卡方檢驗(Chi-square test/Chi-Square Goodness-of-Fit Test)
卡方檢驗是一種用途很廣的計數資料的假設檢驗方法。它屬於非引數檢驗的範疇，主要是比較兩個及兩個以上樣本率( 構成比）以及兩個分類變數的關聯性分析。其根本思想就是在於比較理論頻數和實際頻數的吻合程度或擬合優度問題。
它在分類資料統計推斷中的應用，包括：兩個率或兩個構成比比較的卡方檢驗；多個率或多個構成比比較的卡方檢驗以及分類資料的相關分析等。
Pearson"s chi-square (χ2) test is the best-known of several chi-square tests – statistical procedures whose results are evaluated by reference to the chi-square distribution. Its properties were first investigated by Karl Pearson. In contexts where it is important to make a distinction between the test statistic and its distribution, names similar to Pearson Χ-squared test or statistic are used.