What is the relationship between credits and course hours?

Question

Why can courses at the same department have an apparent disproportionality between credits and hours?

For example at my French university my department offers a 12 credit course with 48 hours of lectures and 72 hours of practical work, a 9 credit course with 24 hours of lectures and 12 hours of practical work, a different 9 credit course with 24 hours of lectures and no practical work, a 6 credit course with 24 hours of lectures and 36 hours of practical work. There are also 0 credit courses with 1 hour of lecture, but these are not really courses and are just included in the course catalog as bonus content to make up a bit for courses not offered in the current year. All of the courses I refer to are Master's level.

How are the number of credits calculated? Intuitively, one would suppose that the number of credits should be somehow proportional to the number of hours, but it is clearly not simply: a x # of lecture hours + b x # of practical hours.

Question: What is the relationship between credits and course hours?

Answer 1

In the European Credit Transfer System (ECTS) one credit point equals 25-30 hours of workload and you are supposed to do 30 credits per semester or 60 per year.

The number of ECTS credits assigned to a particular class is not directly related to the hours in class but to the total workload for the class.

For example, the master thesis is worth 30 ECTS in most German universities, yet there is 0 class time for it. On the other hand, I once took a chemistry lab course with 6 credits => 150-180 hours workload of which 120 hours where time spent in the lab, which was ok because you can't really do much at home except finishing that day's writeup and taking a look at what is planned for the next day.

In your examples, subtract the class time and you're left with around 180-240 hours of self study (reviewing the material, doing homework assignments) for the first three classes and half that for the last one - so the 9 credit classes seem to involve more self study and less time in class.

That's perfectly fine as long as the overall workload is between 25*credits and 30*credits hours.

Since your university is in France, I want to mention that France has specified the workload for 1 ETCS credit point to be 29 hours.

Answer 2

Although only your school can tell you why that specific department has that system, I can give one answer.

If credit is determined by amount of work needed, the larger work is equal to larger credit. It is independent of time spent in class. In your situation, it could mean that some classes do not need extra hours in class, but extra hours outside of class, which is then factored into credits.

A good example of this is in Art/Design/Architecture schools (maybe music and dance as well). In Fine Arts/Architecture, there are usually classes called "Studio" in which they are nearly twice as long as other classes. So, an engineering class (history class or programming class in the same department of architecture) may have lecture 3 hours twice a week, for 3 credits, and a Studio class will have 6 hours twice a week for 3 credits. The perceived workload is thought to be equal as the Studio class naturally requires more time in a studio than at home reading.