It's sort of like a scholastic Heisenberg principle: any assessment changes the nature of the thing being assessed. This is most clearly the case when we look at a student's creative work, as collected in an e-portfolio. If the work is being assessed, then the nature of the e-portfolio changes considerably. It's no longer a place for experiments and failures, but is rather now an exhibit or a performance. The idea, therefore, of using an e-portfolio for assessment is, in essence, a hijacking of the concept of an e-portfolio. There's nothing wrong with assessment. But it should be kept in its proper place. So, at least, says this article.