If I could speak to that question, there are different models of co-operative education programs that different institutions offer. For example, at Conestoga College, my institution, some of our programs are mandatory co-op, meaning when a student applies to that particular academic program, they must successfully complete those co-op work terms in order to complete the credential.
Other programs are what we coin optional co-op programs. That means they might enter in a non co-op stream, and then at some point they apply, and often, based on academic performance, if they are eligible they enter a co-op stream, and then they participate in co-op work terms in that co-op stream.