Quiz

And it would be quite easy to do this as a new question-type plugin ... for someone who knows what he's doing, or maybe for someone who only has a background in programming but could count on a little help if needed.

Here is how I see it. The new question-type plugin could be created from the multiple choice question.

If the correct choices have different values, for example 25% and 50% so that 25% x two choices + 50% x one choice = 100%, you have to consider different question banks for the different values. To keep things simple, at least as a first step, let's assume that the correct choices all have the same value.

Let's introduce the following variables:

• n:      the number of correct choices presented to the student
• np:    the number of correct choices in the choice bank
• m:     the number of incorrect choices presented to the student
• mp:   the number of incorrect choices in the choice bank

The following restrictions apply:

• n >= 1
• m >= 1
• np >= n
• mp >= m

The total number of choices presented to the student is equal to n + m.

In the question settings, the teacher sets the following options:

• Total number of choices presented to the student, n + m
• Number of correct choices presented to the student, n

More or less the same algorithm applies when there is only one correct choice or several correct choices.

The positive values of the correct choices are limited to the single value 1/n, for example 50 % when n = 2. Different negative values can be chosen by the teacher for the incorrect choices.

The np correct choices are identified by their positive value. Of these choices, n choices are chosen at random.

The mp incorrect choices are identified by their null or negative values. From these choices, m choices are chosen at random.

The n and m choices are presented to the student, in order or shuffled.

The student's result is the total of the points obtained for choices n and m.

Detailed procedure

Aiken is only for multiple-choice questions with a single response. If you want to import more complex things, use GIFT.
Here is how to do things.

1. Create your MULTICHOICE, MULTIANSWERS questions in GIFT format.
2. In your Moodle site, go to the questions bank, import and import that GIFT text file as GIFT format (put all those questions in the same category, e.g. "my gift questions"
3. Your GIFT questions will have been converted into MOODLE MULTICHOICE, MULTIANSWERS questions.
4. Export your MOODLE MULTICHOICE, MULTIANSWERS questions to the MOODLE XML format
5. On your Moodle site, install my moodle-qformat_answersselect from my Github at https://github.com/rezeau/moodle-qformat_answersselect
6. Now import those questions using the Random select answers format.

See the Moodle docs at https://docs.moodle.org/311/en/Random_select_answers_question_type#Import_format

In reply to some requests for better import facility from GIFT to the "Random select answers" question type I have developed another question import plugin, qformat_gift_answersselect.

It is available in its alpha, 0.2 release version on my github at https://github.com/rezeau/moodle-qformat_gift_answersselect

Please refer to the official Moodle documentation for GIFT at GIFT_format for more details. Please note that is only imports from GIFT; it does not export.

1. It will only import from a GIFT file those questions formatted according to the Multiple choice or Multiple choice with multiple right answers.
2. It will also accept the following simplified format:
   

   What two people are entombed in Grant's tomb? {
      ~No one
      =Grant
      =Grant's wife
      ~Grant's father
   }

3. It will accept the various [...format...] marks: Options are [html], [moodle], [plain] and [markdown].
4. Optionally, it's possible to specify for each question which "Number of correct and incorrect answers" mode to use among: Use all answers (default mode), The Manual selection mode, The Automatic random selection mode by adding [manual] or [auto] just at the beginning of the question text (either before OR after the [html] or [markdown] etc. format markers (if any). If none of those "selection modes" is use, the import will default to the default mode (Use all answers). Please refer to the Random select answers documentation for more, at Random_select_answers_question_type.
5. When this new import plugin will have been tested by more people I will submit it for inclusion in the Moodle official plugins repo.

I'm pleased to report that my "Random select answers format" plugin has just been approved and is available in the plugins repo at https://moodle.org/plugins/qformat_answersselect