In high school here in Australia, students have one mathematics class which runs all year. The students do maths class most days, and the course passes from one topic to the next, one after the other. They may study quadratic equations for a few weeks, then move on to geometry, then move on to statistics.
An exception to this is in their final year. Students here in South Australia may study Mathematical Studies and concurrently also do Specialist Maths. This means they will be studying two maths topics simultaneously, one in each course.
In most maths courses in first year at my university, the students study two streams simultaneously - lectures on different days alternate between calculus and linear algebra (usually with two different lecturers). The weekly assignments have half their questions on calculus and half on linear algebra. Basically the students are studying two courses concurrently which each have half as much content as a full course.
Recently, one of these courses has been rearranged to return to the high-school style of one topic after the other. This means each topic takes half the time in terms of number of weeks (the same in terms of number of lectures of course). The assessment structure is the same with one assignment every week.
With this recent change, the topics move quickly, so for some students it seems they don't have enough physical time to assimilate the information before they move on to a new topic. Over in the two-stream courses, it seems that the extra time between lectures on the same topic gives students the chance to think about them more. On the other hand, having to think about two topics simultaneously might be an added burden.
Is it actually an advantage to study different mathematical topics concurrently in alternate classes, rather than in blocks one after the other?
Is any advantage just an artifact of the way that classes and assessment are structured? (For example, a possible advantage is having more time between classes on the same topic to think about it and ask questions, but is this just an artifact of students being able to seek help in free time between classes?)
I am particularly interested in answers that give clear reasons from the perspective of student experience and student learning, or which describe experience of trying this in university or high-school classes.