ChiQuadratStatistik
ChiQuadratStatistik is a measure used in statistics to quantify the discrepancy between observed frequencies and frequencies expected under a null hypothesis. It is widely applied in tests of goodness-of-fit, independence in contingency tables, and homogeneity across populations.
The statistic is defined by X^2 = sum_i (O_i - E_i)^2 / E_i, where O_i are observed counts and
Assumptions include that data are counts from random samples, with expected counts sufficiently large (typically E_i
Interpretation centers on the size of the X^2 value and the associated p-value derived from the chi-square
ChiQuadratStatistik is computed in many software packages (for example, R's chisq.test and chi2_contingency in SciPy; SPSS,