I work at Community College of Philadelphia and we would like to use
Webwork for computerized homework in our remedial classes (elementary
algebra). I wonder, if you can find a minute or two to answer the
following question (I would really appreciate it):
If we decide to design a computerized homework for an elementary
algebra, one of 'a must' question would be something like the following:
Collect like terms: 3x+2x
From what I see, the 'standard' way of asking this question in Webwork
would be to ask about the value of a coefficient of x. Unfortunately,
with our population of students, that would not be good enough (common
answer among our students would be 5x^2, so asking just about a
coefficient would not address this problem). I am guessing, that asking
students an open question (i.e. expect them to give the answer 5x),
would cause the following problem: If a student enters as an answer
3x+2x (in other words, do nothing, merely rewrites the problem), the
correct answer would be granted to him. Am I right?
What one can do to
guard against answers like that is to, in addition to comparing
student's answer to correct answer, read student's answer as a string
of symbols and, for example, in this case, make sure that there is no
'+' symbol or (after removing blanks), count number of symbols in a
string and make sure it is not too long (or something of this kind).
Would that type of coding be possible (I believe I saw some examples,
where similar things were done)? Or maybe there are more
straightforward ways of handling this type of questions? Can one use
some logical functions in the process of evaluation of an answer
(correct if a=true and b=true?). Would the answer 3x+2x, when read as
a string be still '3x+2x'?
I am asking because, before Webwork, I
'experimented' a little bit with Maple TA (I am sure, you know it is a
commercial competitor of Webworks) and I had the following problem:
Maple automatically was converting 3x+2x to 5x and even when I was
trying to read student's answer as a string, I was not able to
distinguish between 3x+2x and 5x (I eventually succeeded). Would that
be a case with Webwork?
YOUR HELP WITH ANSWERING MY QUESTION WOULD BE GREATLY APPRECIATED. I AM
TRULY EXCITED TO TRY TO USE WEBWORKS FOR OUR STUDENTS, BUT THE TRUTH
IS, I AM AT THE 'POINT ZERO' (I WILL HAVE TO LEARN EVERYTHING FROM
SCRATCH TO START USING IT), SO IF I KNOW IN ADVANCE, THAT THE ABOVE 'A
MUST' QUESTION CANNOT BE HANDLED BY WOBWORK, I SHOULD NOT EVEN START.
I look forward to hearing from you. Thank you very much for your time.
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