In case anyone (like me) was looking to do this, I just wanted to report the discussion from 2014 'How to import from Canvas to Moodle' still provided me with a solution in Moodle 3 in 2021. The whole solution involved looking in a few different places though, so I thought I'd pull together what I thought may be the key points to help anyone else.
First, hat tip to Jean-Michel Védrine - who, on learning that it would take "a few days for a smarty pants" [see https://moodle.org/mod/forum/discuss.php?d=255301#p1107791] to write the code, found out what a "smarty pants" was, then wrote the code in "2 hours work" [see https://moodle.org/mod/forum/discuss.php?d=255301#p1107791] . There is a rather discouraging discussion in this thread https://moodle.org/mod/forum/discuss.php?d=269499 suggesting that the code no longer works and that Jean-Michel is no longer active - but don't be discouraged! It does still work, there is a more recent version on Github [at https://github.com/jmvedrine/moodle-qformat_canvas] and now in Moodle's own plugin database [here https://moodle.org/plugins/view.php?plugin=qformat_canvas].
I discovered it helps to think of the whole process in three stages:
- Installing the plugin
- Importing the question bank
- Creating the quiz
1. Installing the plugin
Moodle's default install allows importing quizzes in a number of formats but not from Canvas. You have to install an additional plugin to achieve this. There are detailed instructions [here from Jean-Michel https://moodle.org/mod/forum/discuss.php?d=269499 this link was really important] which I followed and which worked perfectly. Probably, you can do the same thing from the plugin database now, [see https://moodle.org/mod/forum/discuss.php?d=269499#p1182019]. After this first stage, Canvas turns up as one of the formats from which quizzes can be imported.
This all takes place at the level of site administration.
2. Importing the question bank
There are a lot of questions in this thread https://moodle.org/mod/forum/discuss.php?d=269499 about Moodle still not finding the questions. The plugin is designed to extract questions from an .xml file, not from the .zip file which Canvas exports. So you have to open up the Canvas .zip file and find the .xml file. There are a few different .xml files inside, and I found the solution to this on a completely different website:
"The result of the [Canvas] export will be a compressed .zip file. Double click the .zip file to extract the individual folders and files...The downloaded quizzes will be in folders given a random alphanumeric serial number. The .xml file will be inside the folder with the same alphanumeric name."
Having identified the .xml file, the next part takes place at the level of course administration (Course administration > Question Bank > Import). Follow the instructions to import the quiz from the .xml file.
After this second stage, the questions are in a bank of questions available to the course.
3. Creating the quiz
Now you can create a quiz in the usual way, and the questions imported from Canvas are available to be selected in your individual quiz.
This final stage is at the level of editing the individual quiz.
Many thanks to all those whose discussions on this forum helped me to this result, and hopefully in return this post may help you.