Re:MIT to no longer consider SAT subject tests in admissions...
by disgruntledphd2 on Friday March 20, 2020 @06:43PM
(#22642466)
That is correct.
So the SATs are (almost certainly) 3-pl (actually 2) IRT models. Essentially, it's a multivariate generalised linear mixed model to estimate both question difficulty and participant ability.
Normally, they'll estimate the abilities on the logistic scale, and use the percentile to back transform to a standard normal.
Most people don't cluster at the top because they are a good proxy for g, which is an imaginary statistical construct that we use to explain differences in school outcomes.
So I had a long digression here about the usefulness of penalties for guessing, but it turns out the SATs don't do that anymore, so wth?
So the SATs are (almost certainly) 3-pl (actually 2) IRT models. Essentially, it's a multivariate generalised linear mixed model to estimate both question difficulty and participant ability.
Normally, they'll estimate the abilities on the logistic scale, and use the percentile to back transform to a standard normal.
Most people don't cluster at the top because they are a good proxy for g, which is an imaginary statistical construct that we use to explain differences in school outcomes.
So I had a long digression here about the usefulness of penalties for guessing, but it turns out the SATs don't do that anymore, so wth?
(ETS invented IRT, that's why I'm pretty sure).