In a world of linear cause-effects mass does not have a special effect on a open on line course. But linear cause-effect is very rare in social sciences.
In a non-linear world effects are unpredictable with our common linear cause-effect thinking habits. [DeLanda, intensive science and virtual philosophy, 187]
In a non-linear world adding students to a mooc could also have unexpected effects. Students differ in so many properties. Adding students will increase the number of differences logarithmic.
“… This implies a pedagogy that (a) seeks to describe ‘successful’ networks (as identified by their properties, which I have characterized as diversity, autonomy, openness, and connectivity) and (b) seeks to describe the practices that lead to such networks, both in the individual and in society (which I have characterized as modeling and demonstration (on the part of a teacher) and practice and reflection (on the part of a learner))….” [Stephen Downes]
The mass in a MOOC is a way of fostering and multiplying diversity. The autonomy of the student is a way of celebrating diversity. Where in most schools diversity is regarded as harmful or annoying in a MOOC it is a positive quality. The connectivity is a way of making use of diversity. A student who connects not only to like-minded fellow students will probably have a better result than a student who has only connected to like-minded students.
The question of the effects of mass in a mooc is changing to the question “Is a network with a greater diversity (more mass) better than a network with lesser diversity (less mass)? ” (See also Jenny Mackness). I do not use the word ‘course’ but do use ‘network’ instead, because the word course has connotations that do not fit with a MOOC.