Estimation for the Rasch Model When Both Ability and Difficulty Parameters are Random.
Abstract
Estimation of the parameters of the Rasch model, a one parameters item response model, is considered when both the item parameters and the ability parameters are considered random quantities. It is assumed that the item parameters are drawn from a N(gamma tau to the 2nd power) distribution, and the abilities are drawn from a N(omicron, sigma to the 2nd power) distribution. A variation of the EM algorithm is used to find approximate maximum likelihood estimates of gamma, tack and sigma. A second approach assumes that the difficulty parameters are drawn from a uniform distribution over part of the real line. Real and simulated data sets are discussed for illustration. Keywords: Statistical data; Tables(Data).
Document Details
- Document Type
- Technical Report
- Publication Date
- Feb 01, 1987
- Accession Number
- ADA179215
Entities
People
- Robert K. Tsutakawa
- Steven E. Rigdon