Negative points in non-adaptive mode does NOT work

Re: Negative points in non-adaptive mode does NOT work

by Joseph Rézeau -
Number of replies: 5
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Hi Gustav,

Thanks for your answer to Josep wink for clearing up the confusion.

I'd like to add two remarks.

1. terminology

What to you think of my suggestion here for re-naming question objects with a view to eliminate confusion?

2. negative points given for a question

I am taking this example from a real-world exam (a competitive language exam for gaining entry to higher schools of commerce, here in France). One part of this exam is an MCQ quiz, consisting of a large number of MCQ questions all exactly on the same model. Each question offers 4 choices, one only is correct. Only one attempt allowed. The scoring system for each question is as follows.

  • student chooses the correct answer -> gets 3 points
  • student chooses a wrong answer -> gets -1 point (negative)
  • student does not answer the question -> gets 0 points

The rationale behind this scoring system is to discourage students to tick an MCQ box "at random" in the hope that they will tick the right choice by chance (and be lucky!).

At the moment, the scoring system in the Moodle quiz module does not allow for this scoring system. What is misleading in the interface of an MCQ editing question in Moodle is that it is possible to give negative scores (ranging from -5% to -100%) which in the end result in a score of zero (in the case of a MCQ with only one answer allowed). I suggest the following alternative solutions. IMPORTANT: I am only talking about MCQ with only one answer allowed.

solution A (my preferred solution)

If we agree that (for the reasons explained in my example above) individual questions may (and in some cases need to) have negative points, then make the negative scoring system work as expected from the present interface (i.e. if a wrong choice is marked for -50%, then if the student selects that choice, then he gets -50% points for that question).

solution B

If solution A is not possible to implement at the moment, then, in order to avoid the confusion, in MCQ One Answer Only type of question, remove all negative scorings from theGrades drop-down list, as they will always result in a score of zero anyway!

I do hope I have not added to the confusion.wide eyes

All the best,

Joseph

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In reply to Joseph Rézeau

Negative marks for questions

by Gustav W Delius -
This feature request to allow negative marks for questions is bug 1647. We could indeed have a quiz option allowing negative marks for questions. It wouldn't be difficult to implement.
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In reply to Gustav W Delius

Re: Negative marks for questions

by Josep M. Fontana -
OK, NOW I understand!! Points are taken off ONLY if more than one answer is allowed! We had been talking about "adaptive mode", where by definition more than one answer is allowed, but since I took "adaptive mode" to be independent of whether one or more answers are allowed, I couldn't understand you properly when you told me that negative points could already be assigned to wrong answers. I didn't get that you meant only when the user can choose more than one answer.

So, yes, it would be nice (and needed, if one notes how many people are apparently surprised that this feature is not part of the quiz module) to be able to take points off for an incorrect answer even in questions where the user is allowed only to chose ONE single answer among the different available answers. I'm not an expert in testing, but as Joseph notes, this is apparently a pretty standard feature in multiple choice testing.  What my colleagues had in mind is exactly what Joseph describes.

Then, most definitely, if this is not too difficult to implement, a lot of people will be happy if you add it to the bag of tricks the quiz module has.

Josep M.
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In reply to Gustav W Delius

Re: Negative marks for questions

by Michael Penney -
We have a few requests from advanced users of online tests, to have an option for 'all or nothing' on the MC/MA question type (so it works like it used to in old Moodle and it still does in lesson: if you don't get all the correct answers on a multiple choice/multiple answer question, you get no credit for that question.

We are using the technique of -100% for all wrong answers, however it still has the problem that if one guesses one of the correct answers they get partial credit, which is not what our faculty want.
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In reply to Joseph Rézeau

Re: Negative points in non-adaptive mode does NOT work

by Josep M. Fontana -
>solution A (my preferred solution)

>If we agree that (for the reasons explained in my example above) individual
>questions may (and in some cases need to) have negative points, then make the
>negative scoring system work as expected from the present interface (i.e. if a
>wrong choice is marked for -50%, then if the student selects that choice, then
>he gets -50% points for that question).

We would need to add, and I think this is the case in the exams you are talking about, that the final score (the sum of the scores for all individual questions) cannot be lower than zero. That is, if the student answers all the questions incorrectly, even if each wrong answer takes points off, the final score will be zero. Conversely, if, say, there are 3 questions in a quiz where the maximum score is 10 and the student answers 2 questions correctly and 1 question incorrectly (with -50% assigned to the incorrect answer), the final score will be 8,33.

Josep M.
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In reply to Josep M. Fontana

Re: Negative points in non-adaptive mode does NOT work

by Joseph Rézeau -
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Josep > We would need to add, and I think this is the case in the exams you are talking about, that the final score (the sum of the scores for all individual questions) cannot be lower than zero.
Yes, of course. I forgot to mention that.
Joseph
Average of ratings: Useful (1)