Item Analysis Calculator
by anonymous
what is Item Analysis Calculator
A calculator for educational assessment that computes the Difficulty Index (P-value) and Discrimination Index (D) to evaluate test item quality. Enter either the basic statistics or use the upper/lower group method to assess how well each item differentiates between high and low performers.
How to use Item Analysis Calculator?
Choose Your Calculation Method
Select between the 'Basic Statistics' method (using overall pass/fail counts) or the 'Upper/Lower Group' method (using data from the top and bottom 27% of performers).
Enter Your Test Item Data
For the Basic method: Enter the total number of test-takers, and the number who answered the item correctly. For the Upper/Lower method: Enter the number of students in the high-performing (Upper) group and low-performing (Lower) group, and how many in each group answered correctly.
Click 'Calculate'
Press the calculate button. The Item Analysis Calculator will instantly compute the Difficulty Index (P-value) and the Discrimination Index (D) for your test item.
Interpret Your Results
Review the calculated values. The P-value (0.0 to 1.0) indicates item difficulty. The D-index (-1.0 to +1.0) indicates how well the item discriminates between high and low scorers. Use the provided guidelines to evaluate item quality.