Hi Natalie,
after much thought, great post by the way.
when you say:
In summary - how can you judge an 'effective' (MOOC) learner when you don't know why they are there, and they don't even know always know why they are there?
I think, you-I-we should not be the only judges...the learner should take ownership and reflect on what they deem to be success-poss endorsed/questioned by those the learner-engages(d) with when adopting the roles of teacher and learner during a MOOC.