EDUCATION (CBSE/UGC NET)

Detailed explanation-1: -For items with one correct alternative worth a single point, the item difficulty is simply the percentage of students who answer an item correctly. In this case, it is also equal to the item mean. The item difficulty index ranges from 0 to 100; the higher the value, the easier the question.

Detailed explanation-2: -"1” indicates the answer was correct; “0” indicates it was incorrect. Follow these steps to determine the Difficulty Index and the Discrimination Index. After the students are arranged with the highest overall scores at the top, count the number of students in the upper and lower group who got each item correct.

Detailed explanation-3: -Calculating Item Difficulty Count the total number of students answering each item correctly. For each item, divide the number answering correctly by the total number of students. This gives you the proportion of students who answered each item correctly. This figure is called the item’s difficulty level.

Detailed explanation-4: -It was calculated using the formula DIF I or P = (H + L) × 100/N, where H = number of students answering the item correctly in the high achieving group, L = number of students answering the item correctly in the low achieving group and N = total number of students in the two groups (including non-responders).