[LON-CAPA-users] entering the same answer twice

Mills, Douglas G dmills at illinois.edu
Mon Mar 30 14:28:31 EDT 2015


Thank you Stuart!

Doug

Douglas Mills
Director of Instructional Technologies
Department of Chemistry
University of Illinois
dmills at illinois.edu
(217) 244-5739







On 3/30/15, 1:22 PM, "Stuart Raeburn" <raeburn at msu.edu> wrote:

>Hi Doug,
>
>> I might be mistaken but I *thought* in the past I'd seen Lon-Capa
>> recognize different ways of expressing the same value as "you've
>> entered that answer before" and not counting the attempt in
>> numericalresponse problems.
>
>Submitting (incorrect) answers of 0.650 and 0.65 for a
>numericalresponse item results in tries being charged for both
>submissions in LON-CAPA versions 2.9, 2.10, and 2.11.
>
>Checking if the same answer was submitted for a numericalresponse item
>is determined in the end_numericalresponse() routine in
>/home/httpd/lib/perl/Apache/caparesponse.pm, which in turn calls the
>check_for_previous() routine in /home/httpd/lib/perl/Apache/response.pm
>
>The check involves a string comparison of the current submission with
>each of the previous submissions made by the student for the same
>instance of the response item.
>
>If there is an exact match between the value of the current submission
>and the value of a past submission, (and the awards also matched),
>then the message: 'You have entered that answer before' will be shown
>and no try will be charged.
>(Exception: survey items, or items where the random seed has changed,
>i.e., randomizetry parameter in effect).
>
>That string comparison part of the implementation has not changed from
>response.pm rev. 1.32 (8/3/2001) and caparesponse.pm rev. 1.38
>(8/3/2001).
>
>
>Stuart Raeburn
>LON-CAPA Academic Consortium
>
>Quoting "Mills, Douglas G" <dmills at illinois.edu>:
>
>> Hi All,
>>
>> I might be mistaken but I *thought* in the past I'd seen Lon-Capa
>> recognize different ways of expressing the same value as "you've
>> entered that answer before" and not counting the attempt in
>> numericalresponse problems. Am I wrong about that?  I thought
>> entries such as .650 and 0.650 were recognized as the same answer
>> and the second entry then not counted as a try where there a limited
>>  number of tries, but if that had been the case in the past, it does
>>  not seem to be the case now.  A student reported using her two
>> tries  on a test retake with just those two answers (why, I don't
>> know!)  and my subsequent testing of that and some other items
>> confirmed  that attempts are not counted by values but by different
>> expressions  of those values -- as if the problem were a
>> stringresponse.  That  was not what I expected.  Thank you for any
>> further guidance on  that. Could it be related to changes addressing
>> differences between  decimals with trailing zeros (so .650 is not
>> the same as .65 for  purposes of sig figs) or something?  Or was I
>> imagining that those  different expressions were recognized as the
>> same value in the past?
>>
>> Doug
>>
>> Douglas Mills
>> Director of Instructional Technologies
>> Department of Chemistry
>> University of Illinois
>> dmills at illinois.edu<mailto:dmills at illinois.edu>
>> (217) 244-5739
>
>_______________________________________________
>LON-CAPA-users mailing list
>LON-CAPA-users at mail.lon-capa.org
>http://mail.lon-capa.org/mailman/listinfo/lon-capa-users



More information about the LON-CAPA-users mailing list