“If you progressively learn the concepts over the course of the unit, then tests will be no problem.”

This is true and applies to all academic study not just computing, but how are you progressively learning these concepts? You could read the text book, summarize it in notes, do a few practice quiz questions and revisit it every few weeks. This is a decent way to memorize anything. But have you actually learned it? Would you be able to effectively apply that information outside of the sandbox that is a test specifically designed to check your memory on the unit content? I would say no. Computing isn’t best learned like that – people study computing because they like to interact with algorithms, not read a book.

You could decide to go and implement every algorithm you come across during the unit, or at least the interesting ones. Then the economy of time comes into play – while you’ll get a deeper understanding, it takes a lot longer and it isn’t as easily compartmentalized the same way the first strategy is. It just doesn’t make sense time management wise for a student to spend a big chunk of their study time coding if it isn’t required for the unit.

Then you really have to ask yourself, are you at university to pass tests? I like to think no.

“In addition, building a portfolio out of assignments gives you little credit.”

I have to completely disagree on this one. Many prospective employers will ask for your GitHub account to have a look at the way you code. Believe it or not, there are still people despite all these tests who graduate without being able to code. I’d also argue that even though assignment are generally limited in scope, they require more creativity than your average test.

It’s very easy to say that it’s the student’s fault, but with the extremely high attrition rate of computing students compared to other degrees, I don’t really think it’s fair to rest the blame solely on the student’s shoulders.

In addition, building a portfolio out of assignments gives you little credit. Why would a professional want to see a portfolio comprised of work that is hardly of your own making? Assignments are designed with clear goals in mind, limited scope and require little creativity.As students, you fill in the blanks of what the assignment specs to produce the end result.

Unfortunately, student feedback on units is also heavily skewed. Only students that really care (whether positive or negative) about the units tend to respond. You miss to much of the total student base to produce a meaning result.