For instance, just last week, the Gates Foundation's Measures of Effective Teaching project noted that the correlation of a given teacher's value-added, from one course or one year to the next, is pretty darn small. It's about .35 to .40 in math, and about .20 in ELA. The value-added measures of teacher performance bounce around--a lot. This isn't a reason to "oppose" value-added assessment, but is good cause to be smart about using it.

Worth your time to click over and browse the Measures of Effective Teaching report from the Gates Foundation linked above.

Talk about a Double Take of the Day while fishing through the RSS reader!

Seriously. Wow.

No experimental evidence for microscopic black holes has been found. This non-observation rules out the existence of microscopic black holes up to a mass of 3.5–4.5 TeV for a range of theoretical models that postulate extra dimensions.

I still love you, string theory... even if you are more philosophy than science.