An eportfolio system gives users a flexible, customizable environment in which they can collect, reflect on, and present the artifacts of their learning. It provides an archive of classroom and extra-curricular work, narratives and descriptions of that work, and a platform for presenting that work for various purposes to various audiences.
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There's also Trent Batson's definition, which is available on the AAEEBL site:
“ePortfolio technology enables learners to manage the complexity and variability of learning designs and opportunities in formal and informal settings in order to gather evidence of their resultant deep learning.”
Updated ePortfolio Matrix, also available on the AAEEBL site and attached here:
We're glad to present the newly updated ePortfolio Comparison Matrix, developed by ePortfolio California's Patricia Donahue during the 2011-2012 webinar series. This Excel file offers a side-by-side comparison of the eportfolio platforms featured during our Exploring ePortfolio Technologies webinar series. (Full resource archive remains available.) 9/30/12
Document for Technical Developers from JISC: attached here.