[LON-CAPA-users] Forcing students to submit valid expressions for formula responses.

[Peter Dencker]

Hi,

I don't think that it is helpful to give hints for syntactically
correct but semantically incorrect submissions: How can one know
what the student means? Students have to learn to produce valid
expressions. One could write simple problems for that purpose and
a short manual.

In my option using customresponse is the appropriate method.
You can find an example (source available) how to check your
mentioned most common syntax problems in

'scl/dencker/testing/examples/simple syntax check 1.problem'

This example is a (hopefully correct) reduction of a more
ambitious library. The library has to be rewritten and is not finished
yet - to put it mildly. I will keep you informed ...

- Peter


Am 21.10.2013 16:23, schrieb Angus Findlay:
> When I give students formula response questions some of them don’t submit valid mathematic expressions. The most common problems are:
> 
> 1) Not having balanced brackets. (i.e. number of left brackets do not match number of right brackets)
> 2) Including invalid characters, such as quotation signs.
> 3) Not including brackets, when necessary. (eg. 2^-1/2 instead of 2^(-1/2))
> 
> I want to tell them that the expression is invalid, tell them why, and allow them to enter it again, without penalty. (Right now my LON-CAPA server times out on them, and asks them to try again later.)
> 
> Is there a piece of standard code I can use for this, or if not, what it the easiest to implement a solution to this?
> 
> Thanks in advance.
> 
> Respectfully,
> ----------------------------------------------
> Mr. Angus Findlay
> Math Department, Mount Allison University
> Sackville, New Brunswick
> 
> email: afindlay at mta.ca    tel: 506-364-2592
> ----------------------------------------------
> 
> 
> 
> 
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-- 
Dr. Peter Dencker
    wissenschaftl. Mitarbeiter

UNIVERSITÄT ZU LÜBECK
    INSTITUT FÜR MATHEMATIK

    Ratzeburger Allee 160
    23562 Lübeck

    Tel +49 451 500 4254
    Fax +49 451 500 3373
    dencker at math.uni-luebeck.de

    www.math.uni-luebeck.de