-
Use point-biserial to discriminate high and low performers | GradeHub
- Point-biserial helps instructors know what makes a good or bad test question, and is essential for faculty developing exams for large class sections. The deciding factor between a good or bad test question is its ability to “discriminate” students who have mastered the material from those who have not. The key is to look at who is getting the item correct and who is getting it wrong. If only the high performing students are getting a question correct, it might be an indicator that the item is too hard.
- One of the most accepted ways to evaluate an item is to calculate a correlation. The technical term for the correlation used in exam item analysis is a point-biserial.
- A high point-biserial reflects the fact that the item is doing a good job of discriminating your high-performing students from your low-performing students.
- Values for point-biserial range from -1.00 to 1.00. Values of 0.15 or higher mean that the item is performing well
- Items with incorrect keys will show point-biserials close to or below zero.
- Point-biserials that are negative signal a big problem. With this pattern, the high-performing students are getting the answer wrong, and the low and/or mid performing students are getting it right
-
-
Digital Accessibility Foundations - Free Online Course | Web Accessibility Initiative (WAI) | W3C
Saturday, October 9, 2021
Weekly Sporto bookmarks (weekly)
Subscribe to:
Post Comments (Atom)
No comments:
Post a Comment