itemanalízist

Item analysis, often referred to as item analysis, is a statistical technique used in educational and psychological testing to evaluate the quality and performance of individual test items. The primary goal of item analysis is to assess whether test items are functioning as intended and to identify any items that may be problematic or biased.

The process typically involves several key steps. First, item difficulty is calculated, which indicates the proportion of examinees who answered the item correctly. Items that are too easy or too difficult may not effectively discriminate between high and low performers. Second, item discrimination is assessed, often using a statistic such as the point-biserial correlation or the discrimination index (DI). This measure helps determine how well an item distinguishes between examinees of different ability levels. Items with low discrimination may not be reliable indicators of examinee ability.

Item analysis also includes examining item bias, which occurs when an item favors or disadvantages a particular group of examinees. This can be assessed using differential item functioning (DIF) analysis, which compares the performance of different groups on an item. Items that exhibit DIF may need to be revised or removed to ensure fairness.

Additionally, item analysis may involve examining the reliability of individual items or sets of items. Reliability measures, such as Cronbach's alpha, assess the consistency and stability of test scores. High reliability indicates that the test items are measuring the same underlying construct consistently.

Overall, item analysis is a crucial component of test development and validation. By evaluating individual test items, educators and psychologists can ensure that their assessments are valid, reliable, and fair, ultimately leading to more accurate and meaningful interpretations of examinee performance.