PBCC , also referred to as the Point-Biserial Correlation shows the relationship between how well students did on the item and their total test score.

• • The range is from –1.00 to 1.00.
    
    The higher the value, the more discriminating the item. A highly discriminating item indicates that the students who had high tests scores got the item correct whereas students who had low test scores got the item incorrect.
    

  • Items with discrimination values near or less than zero should be removed from the test. This indicates that students who overall did poorly on the test did better on that item than students who overall did well. The item may be confusing for your better scoring students in some way.
    

  • The acceptable range: 0.20 or higher

  • The ideal value: The closer to 1.00 the better