calc_posterior_function: Calculate a posterior distribution of theta
In TestDesign: Optimal Test Design Approach to Fixed and Adaptive Test Construction

calc_posterior_function

R Documentation

Calculate a posterior distribution of theta

Calculate a posterior distribution of theta.

calc_posterior_function(
  theta_grid,
  item_parm,
  resp,
  ncat,
  model,
  prior,
  prior_parm
)

`theta_grid`	An equi-spaced grid of theta values.
`item_parm`	A numeric matrix of item parameters.
`resp`	a numeric vector containing item responses.
`ncat`	A numeric vector of the number of response categories by item.
`model`	A numeric vector indicating the IRT models of each item (1: 1PL, 2: 2PL, 3: 3PL, 4: PC, 5: GPC, 6: GR).
`prior`	The type of prior distribution (1: normal, 2: uniform).
`prior_parm`	A numeric vector of hyperparameters for the prior distribution, c(mu, sigma) or c(ll, ul).