[Rasch] Question about difficulty and ability parameters in item response theory
mike at winsteps.com
Wed Aug 14 19:06:31 EST 2013
A formula for estimating item discrimination is shown in
Ranking students is usually based on their person ability estimate
(theta). See Mark Moulton's spreadsheet for the Rasch Model.
2-PL IRT estimation is more complicated. There are free R Statistics
procedures available, see
On 8/14/2013 0:52 AM, fatemeh khalesi wrote:
> My problem is assessment test-takers based on item response theory
> model and i don't know how it's estimate discrimination parameter (a)
> and ranking students.
More information about the Rasch