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  1. Moodle
  2. MDL-28942

Wrong random guess score for mulitple-choice multiple-response questions

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    Details

    • Type: Bug
    • Status: Closed
    • Priority: Minor
    • Resolution: Fixed
    • Affects Version/s: 2.1.1, 2.2
    • Fix Version/s: 2.1.2
    • Component/s: Questions
    • Labels:
    • Testing Instructions:
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      1. Create a quiz with two MC questions, one with radio buttons (One or multiple answers? = One answer only) and one with checkboxes (One or multiple answers? = Multiple answers allowed)
      2. Attempt the quiz as at least two different students.
      2.5 Run cron
      3. As teacher, go to the statistics report (Course -> Quiz -> Results -> Statistics)
      4. Verify that the correct random guess score is shown for the single-choice question, and no random guess score is shown for the multiple-response question.

      Show
      1. Create a quiz with two MC questions, one with radio buttons (One or multiple answers? = One answer only) and one with checkboxes (One or multiple answers? = Multiple answers allowed) 2. Attempt the quiz as at least two different students. 2.5 Run cron 3. As teacher, go to the statistics report (Course -> Quiz -> Results -> Statistics) 4. Verify that the correct random guess score is shown for the single-choice question, and no random guess score is shown for the multiple-response question.
    • Affected Branches:
      MOODLE_21_STABLE, MOODLE_22_STABLE
    • Fixed Branches:
      MOODLE_21_STABLE
    • Pull from Repository:
    • Pull Master Branch:

      Description

      At the moment, it is using the same calculation for single-response and multiple-response questions which is definitely wrong.

      Unfortunately, I don't think there is any feasible way to calculate it for multiple-response questions, other than enumerating all possibilities, and even that depends on whether the question text says "Select all of the choices that ..." or "Select the N choices that ...". Moodle's scoring rules are just too flexible.

      (By comparison, https://github.com/timhunt/moodle-qtype_oumultiresponse has a fairly simple random guess score calculation.)

      I think the only solution is to not attempt to calculate the RGS in this situation. (This is an acceptable thing to do in the question type API.)

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            People

            Assignee:
            timhunt Tim Hunt
            Reporter:
            timhunt Tim Hunt
            Integrator:
            Eloy Lafuente (stronk7)
            Tester:
            Michael de Raadt
            Participants:
            Component watchers:
            Tim Hunt, Andrew Nicols, Jun Pataleta, Michael Hawkins, Shamim Rezaie, Simey Lameze
            Votes:
            0 Vote for this issue
            Watchers:
            1 Start watching this issue

              Dates

              Created:
              Updated:
              Resolved:
              Fix Release Date:
              10/Oct/11