Why not choose all the answers on multiple answer questions?

In Blackboard you can make multiple answer , or "check all that apply" questions. You can also allow partial credit so if they check some of the correct ones, they'll receive some of the points.

The problem is: what if students choose all the answers?

The unmitigated answer is: they get full credit for the question.

Here's how to fix it:

1. Click on Question settings




2. allow the ability to have negative points for answers




3. Within a question, allow for negative scores for incorrect answers. If you want you could allow the negative answers to make the whole question to go negative if you also choose "allow Negative Overall Score for the Question". Otherwise, the worse that they can get for a single question would be zero.
   
   Then click Update Partial Credit%




4. Next notice how many partial credit percent are given to correct answers, and give the same but negative to all wrong answer Partial Credit %'s




5. Now if people choose all the answers, they get zero points for that quetsion