obscore_s {lazy.irt}

R Documentation

Calculate Observed Score Distribution (simple version of obscore)

Description

Calculate Observed Score Distribution (simple version of obscore)

Usage

obscore_s(
  param,
  weight,
  thmin = -4,
  thmax = 4,
  npoints = 31,
  thdist = 1,
  print = 0
)

Arguments

param	Parameter data frame
weight	Weight data frame
thmin	Minimum value of discrete thata value
thmax	Maximum value of discrete thata value
npoints	# of discrete points for theta
thdist	Type of theta distribution = 0 to use uniform, = 1 to use N(0,1)
print	= 1 to print the result

Details

This function calculates the marginal distribution of the test score.

 1. Calculate the conditional distribution of X given theta
 2. Calculate the joint distribution of X and theta.
 3. Calcukate the marginal distribution of X.

In step 1 above, icrf is calculated by lazy.irt::irf and the distribution of the weighted sum of scored multinomial distributions will be calculated by lazy.irt::sumsmnw.

Examples

res <- obscore_s( paramS2, weightS21, print=1 )

---