Cf. Clive Thompson, "The Pen That Never Forgets," NYTimes (Sept. 16, 2010)
Decades of research has found a strong correlation between good notes and good grades: the more detailed and accurate your notes, the better you do in school. That’s partly because the act of taking notes forces you to pay closer attention. But what’s more important, according to some researchers, is that good notes provide a record: most of the benefits from notes come not from taking them but from reviewing them, because no matter how closely we pay attention, we forget things soon after we leave class. “We have feeble memories,” says Ken Kiewra, a professor of educational psychology at the University of Nebraska and one of the world’s leading researchers into note-taking.
Later in the article the point is made that students do even better when they are allowed to use their instructors' notes instead of their own. This suggests jurors should be given transcripts of witnesses' testimony.
&&&The dynamic evidence page
It's here: the law of evidence on Spindle Law. See also this post and this post.