learning activities, not assessment tasks

Learning activities are activities through which students can learn.

Not just learn to do the activity, but learn lots of other things associated with the activity 'through doing the activity'. Associated means surrounding, underpinning, etc - Halliday's up/down/around.

An assessment task is an activity from which you can 'read off' the learning of a student. Again, not just the achievement of the task itself.

Thus, genre theory that targets finalised activities, does not notice that it is learning the wider meaning potential that matters. The genre itself is only a pretext or medium or occasion for learning this larger domain.

In SFL terms, doing a genre is an instancing of a larger system.