EDUCATION (CBSE/UGC NET)

Detailed explanation-1: -The discrimination index value for an item ranges from-1 to +1 with positive numbers over 0.2 reliably implying that an item is positively discriminating.

Detailed explanation-2: -Item discrimination refers to the ability of an item to differentiate among students on the basis of how well they know the material being tested. Various hand calculation procedures have traditionally been used to compare item responses to total test scores using high and low scoring groups of students.

Detailed explanation-3: -A positive discrimination index indicates that those students who got the test item correct also had a high overall exam score. When the discrimination index is negative it means that the examinees in the low performing group got the answer correct at a higher rate than the higher performing group.

Detailed explanation-4: -Item analysis is the act of analyzing student responses to individual exam questions with the intention of evaluating exam quality. It is an important tool to uphold test effectiveness and fairness. Item analysis is likely something educators do both consciously and unconsciously on a regular basis.