transformToBista: Transformation of item and person parameters to the Bista...

In eatModel: Educational Assessment Tools for IRT Modeling using Conquest or TAM

Description

Function uses output of equat1pl to provide two data.frames, one for the item parameters on the bista metric and one for the person parameter (PVs) on the bista metric.

Usage

transformToBista ( equatingList, refPop, cuts, weights = NULL, defaultM = 500, 
                   defaultSD = 100, roman = FALSE)

Arguments

equatingList	The object returned by equat1pl.
refPop	Data frame with at least three columns. First column indicates the domain name. Note that this name must match the domain names in the output of getResults. Second column contains the mean of the reference population. Third column contains the standard deviation of the reference population. Fourth column optionally contains the transformed mean on the Bista metric of the reference population. Fifth column optionally contains the transformed standard deviation on the Bista metric of the reference population. If the fourth and fifth columns are missing, values will be defaulted to 500/100.
cuts	A named list with cut scores. Names of the list must match the domain names in the output of getResults. Each element of the list is a list with one or two elements—the cut scores (in ascending order) and (optionally) the labels of the stages. See the examples of defineModel for further details.
weights	Optional: a data.frame with two columns, first column is person identifier, second columns is individual caseweight. Necessary for the transformation of linking error for (ordered) factors and/or if descriptives of the reference population should be computed directly from the data. See the examples of defineModel for further details.
defaultM	Mean of the reference population on the “bista” metric.
defaultSD	Standard deviation of the reference population in the “bista” metric.
roman	Logical: Use roman numbers for competence level column in the shortened item parameter table dedicated for the “Vergleichsarbeiten”?

Value

A list with three data frames: the first one contains original and transformed item parameters and competence levels. The second one contains original and transformed person parameters and competence levels. The third one contains transformation information.

Note

This version is alpha. Please use with care!

Author(s)

Sebastian Weirich

Examples

# see example 5, 6, and 6a in the help file of defineModel()

eatModel documentation built on May 2, 2019, 6:49 p.m.