Tim Hunt

At Moot DACH last June, Luca Bosh and I had a good look at whether you could implement rubric grading for Essay questions, and we were forced to conclude that we couldn't (without orders of magnitude more work than could be done in a 2-day hackest).

The problem is that the Moodle 'advanced grading' subsystem (which is what manages Rubrics) has a lot of assumptions hard-coded into it which just don't apply to Essay questions. That would take a lot of re-working to resolve.

I think there is a plugin someone has made which does Rubric grading for essays, but they had to resport to some pretty spectacular hackery to work around the limitations.

I wrote this 10+ years ago, but profiling in Moodle still looks a lot like this: https://tjhunt.blogspot.com/2013/05/performance-testing-moodle.html if you use tideways_xhprof.

That is not a proper answer to your question, but it might help.

Is it possible that two users were somehow attempting the quiz with the same login?

If you look in the lots for this quiz, for the actions by this user, are there two different IP addresses showing? That might be a sign that two different people ended up trying to use the same Moodle user account?

This is a bit of a guess, but I wonder if the teacher previewed the quiz before you tidied up, so they still have a preview attempt referring to the deleted questions?

Try this: to to the affected quiz. Edit the settings, and save that form without changing anything. That has the side-effect of deleting any previews that exist. See if that works.

The pattern-match question type is designed for matching natural language text. Therefore, the grading is based around splitting the input into a sequence of words (separate by spaces).

It is not going to work for questions where you need a regex to grade.