Differentiation, accomodation and social promotion

I took the rant I had below and processed it into a thesis.

Social promotion is when we move students up a grade level when they haven't earned it.
(sorry - slipped out of eduspeak - let me try again)
Social promotion is when we move students up a grade level in spite of the fact that the teacher has failed to allow them to uncover the current grade content.

I submit that at least one enabler for social promotion is slippage between differentiation and accommodation. The line between the two is clear and broad in theory, but not so much in practice.

For more discussion see my rant below.