Weighted answers (half and full credit).

This would be useful for me a second language teacher.

Scenario: given a choice of four answers, I would like to have an option of "I don't understand this question" that would give the student half credit.

Why I want this:
- the job of my students is to demonstrate comprehension (and lack of comprehension). In this instance, they are clearly incentivized to do so (without the anxiety of doing so publicly).
- has a better payoff than merely taking a wild guess.
- it's very clear and direct communication to the instructor (which I want to encourage and reward).
- it'll help me identify challenging language structures for my students.
- students may rely less on asking neighbors if there's an answer that's true for them (even if it's "I don't understand").

Perhaps teachers of other subjects can see the possibilities in this.