This article refers to the functionality of the Ortrac Web system. This article describes the Item Performance in the Analysis section
The Item Performance reflects the performance of the item versus the test as a whole. It tells us to what extent an item contributes to isolating the good candidates from the entire pool of test-takers. Talking in very general terms about what I have read, scientific research papers make the following recommendation:
|> 0.4||Excellent Item|
|0.3 - 0.39||Good Item|
|0.2 - 0.29||Fair Item|
|< 0.2||Poor Item|
The interesting items to look for, is a combination of Item Performance and the P-value (Questions Performance), looking at the items that have P < 0.2 and P > 0.7 together low or negative Item Performance.