Calculated Questions and unit penalties

Calculated Questions and unit penalties

by K P -
Number of replies: 9

Right now, when one of my students gets the numerical answer wrong, but the unit right, the feedback (I have adaptive mode on) says "Incorrect" even though the unit is right.  Is there a setting or change in the code I can made so that it says "partially correct" instead.  The issue I am seeing is that students think they have both answers wrong and on their second attempt they change both when really they just needed to recalculate the numeric answer.  At this point, I have just made a general announcement that if you get the number wrong, they don't get credit for only a correct unit.  Their point (which I think is valid) is that if I am assessing them on unit as well, they should get some credit if that is right but the number is wrong.

I love this new question type because it solved several problems I had on assessments, but created this one new one.  I don't really want to have to look at 200 question #1s, #2s, etc just to see if they had the right unit the first time they answered.  I know I can see their response but those are final response.

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In reply to K P

Re: Calculated Questions and unit penalties

by Pierre Pichet -

Thanks for your general remarks and your observation about Incorrect when using adaptative is correctwink.

In the actual question code the grading is stored as a unique number although the question type could display the partial result (cloze question type are another  example of this).

In adaptative mode I do think that there is only one message which is Incorrect but I need to verify closely the actual code.

The planned new question engine for 2.1 (june ?) will get things clearer.

Pierre

 

P.S. a short lunch-time response, more tonight.

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In reply to K P

Re: Calculated Questions and unit penalties

by Pierre Pichet -

"Their point (which I think is valid) is that if I am assessing them on unit as well, they should get some credit if that is right but the number is wrong.'

Most of this development was done to add a  variable penalty if the unit is not the good one, NOT to grade the unit as itself.

I recognize that my terminology "UNIT GRADING' is confusingsad.

As we are in numerical questiontypes, the number is the primary goal.

If personally I want to know from the students which unit should apply in a given circumstance, then I use an additional multiplechoice or a short answer questiontype.

Most often the result can be expressed in various units like Mole/L, millimole/L etc.

I usually use the multichoice option so that the students know the valid units set in the quiz.

If their numerical response match one of the unit, they get the grade for their numerical response and then the penalty is applied if necessary.

This is why there is no valid unit diagnosis until there is a (partially) valid numerical response.

A valid unit is only significant when there is only one unit that can be applied.

I could add "another" option mixed in this single unit case.

Can you show us some examples?

The new planned question engine for 2,1 version (june?) will have a better data structure to handle your specific needs.

We could use this thread to discuss how to improve the actual code.

Pierre

P.S." Is there a setting or change in the code I can made".

We could experiment how to improve the code to fulfill your needs within the limitation of the actual question code.

And definitevely, as people are beginning to use 2,0,  the docs need improvment and you can contribute wink.

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In reply to K P

Re: Calculated Questions and unit penalties

by Pierre Pichet -

However you can obtain the desired effect i.e a grade for the unit if you set a grade of say 10% for any reasonable numerical value using a larger tolerance as the last choice (last answer) and you set the 0,1 of the total question grade as the penalty for bad unit.

Say the answer is My age (68) years

So I set first answer as 68 tolerance 1 as 100% grade value

and a second anwer as 50 tolerance 100 as 10% grade value

and set years as unit .

If the student answers 22 years and no penalty so a final grade of 0,1.

If the student answers 22 year he will have 0,1  for the numerical but a penalty of 0,1 will be applied as he have not the correct unit so a final grade of 0.

This apppears to him as having a 0,1 grade for the correct unit as long as the numerical response is reasonable...

 

Pierre

P.S. This seems to work although there could be an inversion between penalty as % of total question or response. I will look more closely and put a bug about this.

So just wait before applying this on hundred of questions, 2,0 needs some trimmings in the corners...

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In reply to Pierre Pichet

Re: Calculated Questions and unit penalties

by Pierre Pichet -

Kameron,

There is effectively an inversion in the unit grading select text display.

So in numerical/questiontype.php line 1047 replace

$unitgradingtypes = array('1' => get_string('decfractionofquestiongrade', 'qtype_numerical'), '2' => get_string('decfractionofresponsegrade', 'qtype_numerical'));

by


$unitgradingtypes = array('1' => get_string('decfractionofresponsegrade', 'qtype_numerical'), '2' => get_string('decfractionofquestiongrade', 'qtype_numerical'));

And if you set unit penalty as fraction of totalquestion grade (ex 0,1) then to a bad reasonable number the grade will be 10% if the unit is OK and 0% (10% -10%(unit penalty)) if the unit is bad.

For some combinations of grade and penalty, the texts related to the grade and penalty could need to be changed to be more comprehensive.

Your suggestions will be appreciate.

Pierre

P.S. I suggest that we enlarge the scope of MDL-26299 to handle this and other suggestions that could come from the discussions

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In reply to Pierre Pichet

Re: Calculated Questions and unit penalties

by K P -

Wow, Pierre, now that was a response.  I used to do exactly what you suggested a few posts up by having a multiple choice question assess them over the units that would appear on the test.  I found a disconnect though in their thought process.  When asked, lets say for example, what the units are for the force acting on a chair, they would answer "Newtons" which is correct, but when asked to calculate the force and include the correct unit, there would be a breakdown and I would get a correct numerical answer, but a wrong unit.  I have yet to figure out why.  I make them include units with all calculations they do during the course.  Even with the test yesterday I saw the strangest thing happen.  Throughout the current chapter, we have been referencing and writing the unit for current as "A" which is the symbol for Amperes.  Nowhere did I ever write in my modeling such answers as 0.23Amps or 0.23Amperes, it was always 0.23A and so did they on all of their work. On the test, many put Amps, Amp, Ampere, Amperes as the unit, which I went back and set as accepted.  But this might give you an idea of the disconnect I am talking about.

I will make the change in the code you have suggested and see how that works for me and my students.

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In reply to K P

Re: Calculated Questions and unit penalties

by Pierre Pichet -

"answers as 0.23Amps or 0.23Amperes, it was always 0.23A"

You can add as much units as you need and set them with a factor of 1.

You won't have to go back.

Pierre

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In reply to Pierre Pichet

Re: Calculated Questions and unit penalties

by K P -

Pierre,  I never got around to making this change until today and when I did, the change you suggested was already there.  But, it still is not giving 0.1 marks for a correct unit.  I have "as a decimal fraction of the question grade" selected.  The question is worth 1 mark and the penalty is set for 0.1.  That means if they get the numeric answer wrong, but the unit right, they should get 0.1 marks right?

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In reply to K P

Re: Calculated Questions and unit penalties

by Pierre Pichet -

The penalty is substacted from the total grade as the "regular" penalty set for a bad answer preceeding a good one.

If this is the first response so they should get total grade- 0.1* total grade i.i 1-0.1 *  1 = 0.9

The other option  i.e. 0.1 of response grade can be used if you have set a response that worths a 50% grade i.e 0.5.

You can choose to either apply to such a 50% graded response

  • (substact) 0.1 * 1 (total grade option) giving 0.5-0.1=0.4 final grade
  • (substact) 0.1 * 0.5 (which is the grade for this answer ) giving 0.5-0.05=0.45 final grade

Pierre

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In reply to Pierre Pichet

Re: Calculated Questions and unit penalties

by K P -

Wow, ok I am still not sure I understand what I should be doing with this, but I will try some of your suggestions above.

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