discriminointikykyä

Discriminointikykyä, often translated as discriminatory ability or discriminative power, refers to the capacity of a test, item, or measurement to distinguish between individuals who possess a certain trait or attribute and those who do not, or to differentiate between different levels of that trait. In psychometrics and educational measurement, it is a crucial indicator of the quality of an assessment item. A high discriminative power means that an item effectively separates higher-scoring individuals from lower-scoring individuals. For example, in a test of mathematical ability, a high-discriminating item would be answered correctly by most students who perform well on the overall test, and incorrectly by most students who perform poorly on the overall test. Conversely, an item with low discriminative power is less effective, as it does not reliably differentiate between individuals with differing levels of the measured ability. This can occur if the item is too easy, too difficult, or poorly worded. Statistical methods are used to quantify discriminointikykyä, commonly through item analysis. The closer the discriminative index is to 1, the better the item's ability to discriminate. This concept is fundamental in developing reliable and valid assessments, as it helps identify and retain items that contribute meaningfully to the overall measurement of a construct.