Diskriminationsindex
Diskriminationsindex, in the field of psychometrics often abbreviated as DI, is a statistic that measures the extent to which a test item differentiates between examinees with high versus low overall ability. It is used to assess item quality in tests and questionnaires.
Several variants exist. The most common is the top–bottom discrimination index: compute the proportion of correct
Interpretation: For correlation-based measures, values range from -1 to +1, with higher positive values indicating stronger
Applications: used during item analysis in test development to guide item revision or removal and to provide
Limitations: the index depends on the sample and the test’s overall difficulty and dimensionality; it can be
Related concepts include item difficulty, item-total correlation, and differential item functioning.