When instructors design multiple choice questions with more than one correct answer, a student who identifies some correct choices without choosing any incorrect ones has demonstrated real understanding. Yet traditional all-or-nothing grading records that response as a zero. Many instructors are looking for ways to ensure grades more accurately reflect what students actually understand.
To support this, Crowdmark has extended its multiple choice grading system to include partial credit. Assessments can now be scored in three modes:
- Either/or — Full credit if at least one correct choice is selected. No credit if wrong choices are included.
- Partial — Proportional credit for each correct choice selected. No credit if wrong choices are included.
- Exact — Full credit only if the selected choices exactly match the answer key. No credit otherwise.
Multiple choice questions with a single correct answer behave exactly as they did before.
This improvement also includes refinements to Crowdmark’s multiple choice analytics. The underlying statistics have been generalized to work with the full range of scores partial credit produces — not just zeros and ones. The reliability coefficient has been updated from the Kuder-Richardson 20 coefficient to Cronbach’s Alpha, of which KR-20 is a special case. Question discrimination now uses item-rest correlation (or corrected item-total correlation) rather than the classical point-biserial coefficient. For Either/or assessments, the reliability coefficient will remain unchanged with this update, and the item-rest correlation now compares a question to the rest of the multiple choice scores (with that question excluded) to reduce bias in the determination of discrimination.
The goal is to deliver deeper insight into what students understand while giving instructors the information they need to refine and improve their questions.
Detailed documentation of the updated multiple choice analytics — including formulas, worked examples, and guidance on interpreting results across all three scoring modes — is available in our help center. If you are interested in learning more about Crowdmark’s new features, sign-up for training webinars or book a custom session for your institution here.
Ready to try Crowdmark in your courses? Sign up for a free trial.