The Journal of Writing Assessment has many reviews in its archives.
Please read Terry Underwood's "Portfolios across the centuries: A review of Assessing the Portfolio" from Volume 1 Number 2 of JWA.
You can find out more information about this text here: Hamp-Lyons, L. and Condon, W. (2000). Assessing the portfolio: Principles for practice, theory and research. Cresskill, NJ: Hampton Press.