Solution of the Three-Parameter Likelihood Equations of the Item Response Theory by Damped-Newton's Method Computation
Liu Guojun Li Yinsheng
In the item response theory,the item response function,a common assumption is the three-parameter Logistic function: p(θ,a,b,c)=c+(1-c)/(1+e~(-1.7a(θ-b))) where a,b,and c are parameters characterizing the item, θ is examinee ability. Estimations of the parameters are obtained by means of maximum likelihood estimation procedure.Abroad, Newton-Raphson's method is used to solve likelihood equations. In this paper, we apply Damped-Newton's method to obtain better effective results.