Hi,
I will use Moodle in very diverse environment, so I want to make plugin, which separates students by their level of knowledge, so every student get some level. Now on quizzes questions will have level too, and everyone will have quiz generated by their level. I am new to Moodle and its modular structure but is something like altering core database and creating a way of populating quizzes for students achievable by module, or just by altering Moodle core?