Quiz

Jean Michel did some great work with cloze question including, I believe, the options to remove wrong answers which I think will give us the action you are looking for but it is slated for 2.5.  I, for one, am anxiously awaiting the release!!

Agreed!  I use Adaptive mode (no penalties) extensively as a "Homework Check" system to give them as many attempts at a question as they can stand.  I have many questions that would be a complete pain to everyone involved to do anything other than a Cloze question.  I get questions on a regular basis where a student can't figure out what they're getting wrong on a Cloze question.

The bit of code that controls this is the adjust_display_options method in the behaviour class question/behaviour/adaptive/behaviour.php.

    public function adjust_display_options(question_display_options $options) {
        parent::adjust_display_options($options);
        if (!$this->qa->get_state()->is_finished() &&
                $this->qa->get_last_behaviour_var('_try')) {
            $options->feedback = true;
        }
    }

I am not going to attempt to fully explain how that fits into the big picture of how questions work right now. (Exercise for the reader, as they say.) Basically, before we display a question, we give the system a chance to modify what is displayed, so that, for example, we don't display any feedback until after they have submitted a response.

You could experiment with this alternative implementation:

    public function adjust_display_options(question_display_options $options) {
        // Save some bits so we can put them back later.
        $save = clone($options);

        // Do the default thing.
        parent::adjust_display_options($options);

        // Then, if they have just Checked an answer, show them the applicable bits of feedback.
        if (!$this->qa->get_state()->is_finished() &&
                $this->qa->get_last_behaviour_var('_try')) {
            $options->feedback        = $save->feedback;
            $options->correctness     = $save->correctness;
            $options->numpartscorrect = $save->numpartscorrect;
            
        }
    }

I people who use adaptive a lot need to comment on whether that is really better.