** Using WeBWorK **

I just realized that my interface with Moodle can
be used to implement the use of WeBWorK for gateway
testing.

Here's how it would work. The crucial element would
be a WeBWorK course into which students are NOT allowed
to log in. Their WeBWorK passwords would be kept top
secret. The only way they could access the problem
assignments in the course would be via Moodle.

First of all the gateway tests would be prebuilt in
the WeBWorK course as regular WeBWorK homework assignments.
When the student clicks on the link to the gateway test
in Moodle, the URL would specify the actual due date for
the test and the time allowed for the test. The target
script for this URL (a slight variant of the current
moodle2wwk.pl script), would reset the random number
seeds on all the problems and set the due date to
timenow + timeallowed. [All the sensitive data will
be verified by an MD5 checksum with a shared password
between Moodle and the interface script.] Then the
script will call WeBWorK to display problem 1 of the
test. As currently the output from WeBWorK will be
filtered by a wrapper script which will screen out
any responses from WeBWorK about the (in)correctness of
the student's answers. The wrapper script will also
add a timer display somewhere on the page, indicating
how much time is remaining. When the student clicks
the submit button, the wrapper script will automatically
display the next page. However the previous button will
still be available so the student can go back and fix
an answer they may realize is wrong.

The wrapper script will also display a button titled
"Score this Quiz". When the student clicks on this,
the total score for the quiz will be displayed. At
the same time the due date in WeBWorK will be set to
some time in the past, so now the set will be deemed
by WeBWorK to be past due. At the same time the script
will report the score back to Moodle. The student
will also be given the option of going back to Moodle
or going over the problem set once again, this time
with another wrapper script which will allow showing
correct answers. This time instead of a Score the Quiz
button, there will be a Return to Moodle button.
One can also allow for limited or unlimited retakes by
encoding such information in the original URL and the
past due date that is set in WeBWorK after the quiz is
taken and also in the hidden variables in the form.
Again the sensitive hidden variables in the form can
be protected from tampering by cheating students via
MD5 checksums.

Unless I've overlooked something, all this can be
accomplished via relatively modest modifications in
my existing scripts.

Zig

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This is very cunning. I have a couple of questions, mostly to do with the administrative side of things.

• The way I'm reading this, every possible gateway test would be a different webwork assignment. Is this right? Given the ability to reset the seed the student uses for any given assignment, this isn't necessarily an issue. However, for comparison, we're currently doing a derivative gateway which is generated with seven topics, each drawn from a bank of about 100 questions---at face value this could be a lot of assignments. Of course, the more relevant question is how many times students take the test. I'd have to check to be sure, but I think the upper bound for us is probably over 20 and less than 40.
  
• Following this line of thought, I assume that the Moodle script would randomly select which of the gateway assignments was returned to the student.
  
• Does Moodle allow the easy aggregation of the results of the different tests (webwork assignments) too? In particular, most instructors are going to want a list of the students in their class with an indication of whether or not they passed the gateway test. And then the ability to go and look at the tests that each of the students took.
  

I hope those make sense. I haven't had any coffee yet this morning and it's starting to seem that might be to my detriment.

Thanks,
Gavin

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