Completion rates for Massive Open Online Courses (MOOC) bug their creators because of the massive fall-out. Like the half-life of something in a pond at Sellafield the figures can half in a week, and half again in another couple of weeks and at the end of a 12 week course there are 50 people left out of the original 15,000.
The excuses and reasons for this drop-out are multivarious: many never planned to start the course - it is too easy to sign up to something that is free; an early poor experience puts people off: it is not for them, too hard, too boring, irrelevant or time consuming. They can have a technical melt down too: the learning platform is pants, or their kit and connection isn't up to it. A course can over promise and under deliver; there is a terribly fine balance and on the side of the creators ignorance of their students who can and will be 'anyone' : digitally literate or not, English their first language or not, lect school young with no qualifications or a professor nosing in on something that is their expertise ...
Reasons that people stick include: they've paid for it, it should enhance their job prospects or working life (it has practical worth), they 'like' the educator(s), they 'like' their fellow students and/or 'enjoy' the platform, its functionality and experience. The intrinsic rather than the extrinsic motivators work best.
A responsive 'platform' by which I mean the educational establishment or organisation (The OU, Coursera, FutureLearn, EDx) will identify and fix sticking points: a flood of people quit after the third multiplechoice assessment - you fix it; the 12th too-long to camera talking head of the same person and you jazz them up, get someonelse or look for alternative approaches; and you acknowledge that everyone studying 'at a distance' and 'online' probably never had the time to set aside to study your course in the first time so will need time to adjust - to make time. And life is fickle, they may have setbacks. Great therefore if on a 3, or 5 or even a 12 week course or module that they can 'elect' at any stage to 'switch' to the next 'presentation' - so they pick it up in a few weeks.
With switching I wonder if there could be a way to discourage multiple switching though. I fear that what can happen is that having switched once out of expediency, then a second time 'because you can' then the third time there is some kind of behavioural pattern established and the person will never complete the course. Were a student physically attending class an aware supervisor would cause the student to think twice on the second 'default' switching and may put 'soft' barriers in the way of the third - after all, the hidden agenda here is about 'completion rates': one indicator of a successful course is the percentage whi make it to the end.
By not having switching, rather like having students paying a fee, you force their hand - gently, and sometimes of necessity. You have to face up to the genuine challenges of learning: you face and overcome obstacles whether they occur in your real home or professional life or because you are struggling 'in class'. Either you have, or develop resilience; you seek help and advice and get it.