Linking ePortfolios and Student Achievement?

I received the following request by e-mail:

Recently I became interested in e-portfolio and its implementation in my Small Learning Community (SLC). However, I need data/research that can support my belief that e-portfolio can improve student achievement in all areas. I have visited your sites and others and done some researched but the info i have attained is not specific enough to persuave my colleagues. If you could, please provide me with some specific research regarding student achievement. Thank you.

Here is my response:

You did not mention the educational context for your question. Elementary school? High School? College? In any case, I am not aware of any research that specifically ties e-Portfolios with improved student achievement (assessed, I assume, with standardized test scores). However, there is substantial research that supports the use of formative, classroom assessment (assessment FOR learning as opposed to assessment OF learning) with increased student achievement. Look at the meta-analysis conducted by Black and Wiliam in the U.K.: http://www.pdkintl.org/kappan/kbla9810.htm
Also, the Assessment Reform Group: http://www.qca.org.uk/7659.html

That type of formative assessment is well facilitated using a portfolio for that purpose; a portfolio used in classroom-based assessment is more of a communication tool about student learning than an instructional strategy.

I am doing a research project right now on using portfolios in high schools, but we are not looking specifically at student achievement. Rather, we are looking at student engagement, motivation and collaboration using technology, which should impact on student achievement. I think it is problematic to tie student test scores directly with the use of electronic portfolios, since you are really crossing different pedogogical paradigms. And there are too many other intervening variables in the process. You really need to look at other effects of electronic portfolios. Standardized testing only addresses a limited type of student learning; portfolios can be used to document a broader range of student learning.

There may be other research being conducted at this time, but it is too early to make any conclusions. I would be interested if anyone knows of any of these studies.