Anyone interested in testing it is invited to check it out, but PLEASE BACKUP YOUR DATABASE TABLES first. The upgrade script does some substantial changes to the quiz module tables and has not been tested sufficiently. Please report any bugs, anything curious that you observe, and any suggestions for changes.
It would be particularly useful if you have a site with a lot of quizzes and a lot of student attempts to test the upgrade procedure. Currently the upgrade script is still very verbose because I thought this might help in testing.
There is not yet any support of Postgres databases. I simply don't know enough about Postgres. Can someone with some knowledge look at mod/quiz/db/mysql.php and see how it has to be changed to give us a new mod/quiz/db/postgres.php?
The backup and restore code has not yet been updated. So at the moment you can not backup or restore quizzes in Moodle 1.5. This is now top-priority for us.
On the surface you should not notice too many differences to what was already in Moodle 1.5 except for the new tabbed teacher interface, the new page break mechanism, and some new quiz settings. But under the hood the whole runtime model has changed.
The change in the code has mainly been done in order to allow Moodle to handle adaptive questions. They are questions that allow repeated interactions with the student within a single attempt and that can adapt themselves in response to the student's answers. See for example the following definition from the IMS QTI Information Model:
An adaptive item is an Item that adapts either its appearance, its scoring (Response Processing) or both in response to each of the candidate's Attempts. For example, an adaptive item may start by prompting the candidate with a box for free-text entry but, on receiving an unsatisfactory answer, present a simple choice Interaction instead and award fewer marks for subsequently identifying the correct response. Adaptivity allows authors to create items for use in formative situations which both help to guide candidates through a given task while also providing an Outcome that takes into consideration their path, enabling better subsequent content sequencing decisions to be made.
Unfortunately Moodle does not yet have any adaptive question types of its own. However the new quiz module allows you to connect to question web services that perform the rendering and scoring of adaptive items. These external questions are integrated into the Moodle quizzes like any native Moodle question. But that must be the topic of a separate post.