Effective Practices with ePortfolios
The sections on "Investigating ePortfolios: A Learner's Perspective" (pp 10-15) and "Investigating ePortfolios: A Lifelong Learning Perspective." (pp 28-33) provide case studies showng the benefits of ePortfolios for academic learning and professional development.
http://www.jisc.ac.uk/media/documents/publications/effectivepracticeeportfolios.pdf