equate (version 0.1-1)

se.boot: Bootstrap Standard Errors of Equating

Description

This function returns the standard deviation of equated scores over multiple replications of a specified equating.

Usage

se.boot(x, y, xn = sum(x[,ncol(x)]), yn = sum(y[,ncol(y)]), 
  reps = 500, eqfun, ...)

Arguments

x, y

score distributions of class freqtab for forms X and Y. Under the random groups design (i.e., no anchor test) x and y will each contain the score scale in column 1

xn, yn

integers specifying the number of scores to sample from each distribution at each replication (default is the total number of scores in each)

reps

number of replications

eqfun

string indicating the equating function

...

further arguments passed to or from other methods

Value

• Returns a vector of standard deviations, one per score scale point.

Details

Samples are drawn of size xn and yn, with replacement, from each score distribution. Form Y equivalents of each form X score are then obtained using the specified equating function eqfun. This process is repeated reps times. This function is called by equate.

Examples

xtab <- freqtab(KBneat$x[,1],0:36)
ytab <- freqtab(KBneat$y[,1],0:36)
se.boot(xtab,ytab,reps=100,eqfun="equate.ln")