An email I sent to a colleague the other day, relevant to
Andy's article in
PDK, at least peripherally in
using statistical error to explain away the differences in how certain folks operate in the world. Also, n
ice shout out to Kinder and
Iyengar. Those guys bring me back to
UVA Politics.
"OK, let me try this again. I'm trying to understand how confidence intervals (CI) can be explained in regards to
AYP, particularly in light of something like growth models and
ED's decision to not allow states to use CI when reporting growth under the Growth Model pilot.
The way I understand it.
When states don't use confidence intervals they increase the chance of making a Type II error. In the case of
NCLB this gets
operationalized as identifying subgroups as having met proficiency when they actually have not met proficiency. A Type I error in the context of
NCLB would be the inverse: identifying a subgroup as proficient when they actually are not proficient. In statistics we are usually more concerned about making a Type II error because erring on the side of caution is good for a lot of things--like keeping people alive in medical trials.
But with regards to schools and calculating
AYP, ED seems more concerned (based upon their general indifference to confidence intervals) about making a Type I error, or identifying a subgroup as having met proficiency when the subgroup in fact has not met proficiency.
Maybe it's not possible to talk about confidence intervals in this way--the unit of analysis being subgroups."
Labels: AYP, Error, NCLB, PDK, Rotherham, Statistical
