Tim Hunt

Is the relevant thing here 'Agile', or is it acutally just about Open Source? In an Open Source context, there is nothing surprising about the story of that issue.

What is the best introduction to the world of Open Source these days? 20 years ago, I would have said 'The Cathedral and the Bazaar', and that might still be as good as anything. http://www.catb.org/~esr/writings/cathedral-bazaar/

The most detailed description we have of how the statistics calculations work are https://docs.moodle.org/dev/Quiz_statistics_calculations and https://docs.moodle.org/dev/Quiz_statistics_calculations_in_practice.

Well, actually, THE most accurate description of what the code currently does is the code itself, but that is hard to understand. (https://github.com/moodle/moodle/blob/f747c15cbf1c1c963a9592a73b167b969ec33d75/public/question/classes/statistics/questions/calculator.php#L92 if you are feeling brave!)

Hopefully somewhere there you can find the answer you seek. When this was originally implemented many years ago, a lot of careful thought was put in to making it rigorous, but I no longer remember all the details.

Which version are you currently running?

Ordering question type was added to the standard Moodle release some time ago, so bug reports and suggestion need to go into the tracker. https://moodledev.io/general/development/tracker

If there are questions that are breaking things, and you can't delete them through the Moodle UI, then the only option I can think of is to go into the database and delete them there - if that is within your skillset.

If you are contemplating something like that, it is a good idea to have (or be able to create) a clone of your actual Moodle site, where you can test things and see what happens before doing them on your real site. Most people running their own Moodle server will have this, to be able to test upgrades and things, but I am not sure if you do.

Anway, to clean up the data in the database, you have to find it then delete it. For questions this is a little tricky because data is spread over serveral tables: mdl_question, question_versions, question_bank_entries, the for ddmatch questions, additionally question_hints, qtype_ddmatch_options, and qtype_ddmatch_subquestions.


The other approach would be to get the code fixed somehow. Acutally, I think someone might have proposed a fix for this: https://github.com/dualcube/moodle-qtype_ddmatch/pull/62/changes. Again, I don't know if you are in a position to try applying that code change to your Moodle site, and seeing if it fixes the problem.