Diskriminationsparameter
Diskriminationsparameter is a statistical quantity used to quantify how well one or more variables differentiate between two or more predefined groups. It appears most commonly in analysis of variance (ANOVA), multivariate pattern classification, and item analysis in educational testing. The parameter is generally defined as the ratio of the variance between group means to the residual or within‑group variance. For two groups, the formula can be written as D = (μ₁−μ₂)²/(σ₁²+σ₂²), where μ and σ² are the means and variances of the groups. In the case of multiple groups, a generalized form involves the eigenvalues of the between‑group scatter matrix divided by the within‑group scatter matrix.
The discriminationsparameter provides a dimensionless measure of class separation; values close to zero indicate poor discrimination,
Historically the concept dates back to the early twentieth century work of Karl Pearson, Ronald Fisher, and