(Too) Many ways
Reading along Heather Kanuka (2oo2), it seems that the problem (at least one of them, 8-)) resides in the multiplicity of learning procedures and the management of the time available for applying them. At the same time, the instructor in Distance education has to manage the individual differences of the group of students, without looking like creating different approaches for each one (which is, in fact, what is needed, but that puts the instructor in a tight spot).
With effective coordination, the different procedures can be spread among the different courses running simultaneously. This model differs in this aspect from a sequence of modular courses, created almost inevitably problems of student dispersion among the various subjects. But, it also allows crossbreeding among the different themes, something that is not possible in a sequential model.
One of the aspects that I really don’t like is when different themes in a course are prepared by different groups of students. How to manage an effective participation of the other students, working on different themes, in the serious critique of the fellows’ work in a context of time scarcity?
HKanuka (2002). A Principled Approach to Facilitating Distance Education: The Internet, Higher Education and Higher Levels of Learning. JOURNAL OF DISTANCE EDUCATION 17(2): 70-86.