Add multi-choice (checkbox) question

[PhilippImhof]

Description of proposed feature

Formulas currently allows for single-choice questions with either radio boxes or a drop down field. It could be extended to allow for multiple-choice questions with checkboxes where more than one answer can be checked.

How can the new feature be used?

Thanks to custom grading criterion, it would be possible to give fine-tuned grades:

Select all European countries:
[ ] France
[ ] Switzerland
[ ] China
[ ] Canada

If the student selects France and Switzerland only, they could get 100%. If they select only France or Switzerland, they could get 50%. And if they check China and/or Canada, they could get 0%, no matter if they also selected France or Switzerland.

Additional comments

To my knowledge, the desired behaviour is not yet available in Moodle. One can award points for correct answers and define deductions for wrong answers, but more complex grading is not possible.