If you’re considering incorporating ePortfolios into your teaching (and if you’re not you should) there’s a good review by Helen Barret available.
This paper provides the theoretical background for a study of student learning, engagement and collaboration through the development of electronic portfolios. After covering an overview of the limited research on portfolios in education, definitions, multiple purposes of portfolios, and conflicting theoretical paradigms are discussed. Principles of student motivation and engagement are covered, along with philosophical and assessment issues and the importance of reflection in learning. The relationship between storytelling and reflection is elaborated. Finally, the paper describes several technology tools that engage learners in reflecting, including blogging and digital storytelling.
You can read the full report here.