CDM (version 2.7-7)

ideal.response.pattern: Ideal Response Pattern

Description

This function computes the ideal response pattern which is the latent item response $\eta_{lj} = \prod_{k=1}^K \alpha_{lk}$ for a person with skill profile $l$ at item $j$.

Usage

ideal.response.pattern(q.matrix, skillspace = NULL)

Arguments

q.matrix

The Q-matrix

skillspace

An optional skill space matrix. If it is not provided, then all skill classes are used for creating an ideal response pattern.

Value

• A list with following entries
• idealresp
  A matrix with ideal response patterns
• skillspace
  Used skill space

Examples

#############################################################################
# EXAMPLE 1: Ideal response pattern sim.qmatrix
#############################################################################

data(sim.qmatrix)

q.matrix <- sim.qmatrix
ideal.response.pattern( q.matrix )

# compute ideal responses for a reduced skill space
skillspace <- matrix( c( 0,1,0 ,
                         1,1,0 ) , 2 ,3 , byrow=TRUE )
ideal.response.pattern( q.matrix , skillspace=skillspace)