Harsher OU marking?

The boundaries are different, but this is probably more reflective of the way in which the courses are examined than it being "harder" necessarily. Just like how in the US to get an A you usually need to get 90% or above, this doesn't mean that their courses are harder, it just means they're marked and assessed differently. It's like asking which weighs more, a ton of bricks or a ton of feathers; the answer is the same, there is just a difference in the material. The OU is bricks, concrete and quite structured, while most "brick" unis are feathers; much larger volume and more expansive with a lot of room to go in different directions.

In both that US example and with the OU, the format is a bit more "closed" (more similar to A-level, I think) with fewer open-ended questions and hence less "room at the top" of the grade boundaries to indicate extremely high level work well beyond the scope of the course. Since often exams might be multiple choice, or TMAs very structured, there is simply less scope to be able to do that in many modules (although there are certain project/extended essay based modules where you do have this scope).

Anyway, it is perfectly possible to get distinctions at the OU, which is the highest grade of pass in a module (and if you got all or most of your modules at distinction you would probably be awarded a 1st class degree in the end). I got distinctions in both the modules I did wit hthe OU (although admittedly one had the exam cancelled which might've helped for that one ) and I don't think I had to study more than I did for the modules I got 1sts in when I was at a brick uni in order to achieve that.

Thanks so much for that detailed answer - I never thought of it as being linked to different marking standards, I just presumed the exams at OU were more or less identical to brick uni’s and therefore marking standards almost identical! Is this not the case?