M: Multiplier for first deriviative of log-likelihood of 2PL.

In peterhalpin/BearShare: Psychometric models of small group collaborations

Description

Writing the derivative of the log-likelihood of the 2PL in theta for a single item as M * dIRF, this function computes (a matrix of values of) M, with dIRF being the first deriviative of the 2PL IRF. Called by functions that compute derivative of the log-likelihood.

Usage

M(resp, parms, theta)

Arguments

resp	a matrix or data.frame containing the binary item responses.
parms	a named list or data.frame with elements parms$alpha and parms$beta corresponding to the discrimination and difficulty parameters of the 2PL model, respectively.
theta	the latent trait.

Value

dim(resp)-matrix of multipliers.

peterhalpin/BearShare documentation built on May 25, 2019, 12:48 a.m.