blue_equate: This functions calculates parameters to equate measurements...

In jsaraviadrago/bluegrafir: Psychometric tools for structural equation models and scale comparisons

Description

It calculates mean-mean parameters in order to do a linear transformation of a scale to make it comparable with another one. The function does the mean-mean transformation for test in a IRT framework, a good reference is: Kolen, M & Brennan, R. (2014) Test equating, scaling and linking. Methods and practice. Third edition. NY: Springer.

Usage

blue_equate(x, y, x_ee, y_ee)

Arguments

x	vector of continous variable that you want to equate
y	vector of continous variable that you want to equate to. This variable will have the same metric as parameter x.
x_ee	vector of continous variable with estimated error.
y_ee	vector of continous variable with estimated error.

Value

The output is a list of tibbles with the calculated parameters, the items and the difficulty of items of one group and the other. Finally a the plot with control bands to check item displacement.

Author(s)

Juan Carlos Saravia

Examples

x1 <- c(1,2,3,4,5,6,7,8,9,10)
y1 <- c(2,3,4,5,6,7,9,8,6,5)
x.ee1 <- c(1,2,3,5,6,7,8,9,20,10)
y.ee1 <- c(9,8,7,6,5,4,3,2,1,2)
equate_table <- data.frame(x1,x.ee1,y1,y.ee1)
blue_equate(equate_table$x1,equate_table$y1,
equate_table$x.ee1,
equate_table$y.ee1)

jsaraviadrago/bluegrafir documentation built on July 20, 2020, 3:01 a.m.