AMCnumericChoices wrong scoring

Added by Paco Riviere about 1 month ago

Hi,
I never used numerichoices before in a real test.
I now have a simple numeric question in a real test with the following code:

\begin{questionmultx}{question}\\
Some text ...
\parbox[c]{.92\linewidth}{
\AMCnumericChoices{\VQsol}{exact = 2, decimals = 0, digits = 3, sign = false, scoreexact = 2, approx=5, scoreapprox=1}}
\parbox[c]{.04\linewidth}{
\end{questionmultx}}

I pretended to give 2 points for an exact answer and 1 for an answer not far from the rigth one.

Once annotated all correct answers are properly marked, with a blue cross, but some are given 2/2 points and some 0/0. Calculation is so simple only addtion, substraction ans multiply are involved, no place for decimals or rounding issues.
All wrong answers mark with a red cross, but some are scored 0/0 and some 0/2.

Default questions annotation setting is "%s/%m" (students mark/Maximum mscore).

So answers are properly marked but not scored as I expected.

Obviously I did something wrong, but cannot guess what.

Thanks in advance
Thanks in advance for your help.

Obviously


Replies (12)

RE: AMCnumericChoices wrong scoring - Added by Alexis Bienvenüe about 1 month ago

some are given 2/2 points and some 0/0.

Can you show us an example?

RE: AMCnumericChoices wrong scoring - Added by Paco Riviere about 1 month ago

Your right, Alexis, in fact the example shpuld be:

\begin{questionmultx}{question}\\
Some text ... *\VQfor{}* ?
\parbox[c]{.92\linewidth}{
\AMCnumericChoices{\VQsol}{exact = 2, decimals = 0, digits = 3, sign = false, scoreexact = 2, approx=5, scoreapprox=1}}
\parbox[c]{.04\linewidth}{
\end{questionmultx}}

Excuse my mistake

RE: AMCnumericChoices wrong scoring - Added by Paco Riviere about 1 month ago

Here are some partial screenshots of diferents marks to the same question

2_2.png - Mark 2/2 (12.6 kB)

0_2.png - Mark 0/2 (11.7 kB)

0_0.png - Mark 0/0 (16.7 kB)

RE: AMCnumericChoices wrong scoring - Added by Paco Riviere about 1 month ago

Analizing questions and answers one by one manually I notice marks 0/2 and 2/2 are all when \VQSol value is zero!
If answered correctly, then they are marked 2/2 and if wrong, 0/2 as expected.
The problem comes with exercises where \VQsol is not zero, as even if markings are correct, then the questions are weigthed null (2/0, or 0/0) and not computed on the exam note

RE: AMCnumericChoices wrong scoring - Added by Alexis Bienvenüe about 1 month ago

What are the parbox'es for? The problem remains without them?
Can you join a complete source file? I did not succeed including your code without compiling error.

RE: AMCnumericChoices wrong scoring - Added by Paco Riviere about 1 month ago

In the parbox there is an image illustrating the question. I try to reproduce the code on a simpler file and upload the code.

RE: AMCnumericChoices wrong scoring - Added by Paco Riviere about 1 month ago

Here is the code on a simple file, without images. This is not the real question but gets the same result.

source.tex (3.2 kB)

RE: AMCnumericChoices wrong scoring - Added by Paco Riviere about 1 month ago

Sorry, please ignore the source.tex on the preceading post. Was not the used code.
Take this new one with this sample answer scan and check that student 103 is given a full score when his answer is wrong

source.tex (3.2 kB)

SampleSCAN.pdf (63.7 kB)

RE: AMCnumericChoices wrong scoring - Added by Alexis Bienvenüe about 1 month ago

Thanks. From your code,

\FPeval\VQfor{trunc(10+random*10,0)}
\FPeval\VQsol{round((10-\VQfor)*5,0)}

it appears that \VQsol is nonpositive. When negative, it can't be coded because sign=false, leading to some problems.
Maybe a mistake in the formula for \VQsol?

RE: AMCnumericChoices wrong scoring - Added by Paco Riviere about 1 month ago

The answer should be positive. But your right as problems come when the result is zero.
Do you think that if the result is positive and nonzero it will be scored correctly?

RE: AMCnumericChoices wrong scoring - Added by Alexis Bienvenüe about 1 month ago

The answer should be positive

Maybe the correct formula is

\FPeval\VQsol{round((\VQfor-10)*5,0)}

Do you think that if the result is positive and nonzero it will be scored correctly?

Yes.

RE: AMCnumericChoices wrong scoring - Added by Paco Riviere about 1 month ago

The point was the result was sometimes negative. This solved the problem.

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