pw.eval {choiceDes}

INTERNAL: Evaluate two-way frequencies

Description

Internal function to evaluate whether the two-way (pairwise) frequencies of items in a matrix are balanced.

Usage

pw.eval(items, shown, drows, des)

Arguments

items

The total number of items shown in a tradeoff exercise.

shown

The number of items shown in each tradeoff task.

drows

The number of rows in the tradeoff design matrix.

des

A matrix consisting of the levels-coded tradeoff design.

Details

Evaluates the two-way (pairwise) frequencies of items in a tradeoff design matrix and returns those frequencies as well as the off-diagonal mean and standard deviation of the frequencies.

This function is called internally by tradeoff.des.

Value

tbl

A matrix of the two-way frequencies (pairs of items) in the tradeoff design.

od.mean

The mean of the off-diagonal elements in tbl.

od.stdv

The standard deviation of the off-diagonal elements in tbl.

See Also

tradeoff.des

Examples

## INTERNAL USE ONLY