THE ROLE OF PSYCHOMETRIC INDICATORS IN ASSESSING THE QUALITY OF PSYCHODIAGNOSTIC METHODS
Abstract
The article examines the principal psychometric indicators of test item quality, including item difficulty, the discrimination coefficient, the discrimination index, reliability, validity, and representativeness, as applied in the development and adaptation of psychodiagnostic instruments. Particular attention is given to discrimination as one of the key criteria for evaluating test item quality. Discrimination is defined as the ability of a test item to differentiate between examinees with high overall test scores and those with low scores. In other words, a high-quality item should contribute to a statistically significant distinction among respondents based on the level of the measured construct. The article further substantiates that, in norm-referenced educational testing–where the primary objective is to classify learners according to their level of knowledge–the discrimination index of each item constitutes a fundamentally important component of test quality assurance. It is the item’s capacity for differentiation that determines its diagnostic value and practical significance.