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I came across a very good scaling formula to scale theta based on Item Response Theory to the scale of 31-68.

The original post is here. The formula looks like this:

$f(x) = \frac{(b-a)(x-min)}{max-min} + a$

Would anyone kindly point out where I can find this type of scaling in a book or journal article because I need to cite it from such publications?

kjetil b halvorsen
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Faisal Mustafa
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1 Answers1

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I can’t imagine that the formula to rescale a variable from one range to another has earned a publication, because it’s rather intuitive. It’s also not specific to IRT. You first scale the variable to [0, 1], then stretch it out to [a, b].

If you still feel the urge to cite that formula, there’s a “Cite” button on the Cross Validated answer you linked to.

Arya McCarthy
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