Wolfgang Greller describes four categories of learning- two of which non-formal & accidental should make a good addition to any consideration of ePortfolios/PLEs.
– formal learning is where the objectives (learning outcomes), the method, management, and the assessment of the learning outcomes are by and large created externally.
– non-formal learning is where the learning outcomes are internally defined (by the learner), maybe also the method. The assessment can be self-assessment or external assessment.
– informal learning is where no concrete learning outcomes have been defined, but intentional learning happens that is self-motivated. Informal learning requires no assessment, although self-assessment or reflection are not explicitly excluded.
– heuristic or accidental learning is stumbling across knowledge that results in mental intake and thus gets added to the internal/personal knowledge base.