R: Approximate Conversion of Graded Response Items to Partial...

fitP2G {lazy.irtx}

R Documentation

Approximate Conversion of Graded Response Items to Partial Credit Items Using Logit Transformation

Description

Approximate Conversion of Graded Response Items to Partial Credit Items Using Logit Transformation

Usage

fitP2G(paramG, wtype = 1, DinP = 1, dataframe = 1, npoints = 21,
  thmin = -3, thmax = 3, maxabsv = 3, print = 1, plot = 0,
  debug = 0)

Arguments

`paramG`	Item Parameter Data Frame for Graded Response Items
`wtype`	= 1 to use normal weight, else uniform
`DinP`	= 1 to include D=1.7 in logistic function
`dataframe`	= 1 to create parameter data frame, not matrix
`npoints`	# of discrete points for theta
`thmin`	Minimum value of discrete thata value
`thmax`	Maximum value of discrete thata value
`maxabsv`	Maximum absolute value of the weight
`print`	= 1 to print result
`plot`	= 1 to plot result
`debug`	= 1 to print intemediate result

Value

A list of: Partial Credit Model Item Parameter Data Frame in Nominal Format
Partial Credit Model Item Parameter Data Frame in Nominal Format0
Partial Credit Model Item Parameter Data Frame in Standard Format

Examples

paramP1 <- fitP2G( paramS1[3,], npoints=21, plot=1, print=1 )$paramP
paramG1 <- fitG2P( paramP1, npoints=21, plot=1, print=1 )

[Package lazy.irtx version 1.0.1 Index]