kefreq: Test Score Frequency Tabulation

In kequate: The Kernel Method of Test Equating

Test Score Frequency Tabulation

Description

Tabulates the frequencies of score values/combinations of score values from data at the individual level. Can handle univariate or bivariate scores.

Usage

kefreq(in1, xscores, in2, ascores)

Arguments

in1	A numeric vector with the total test scores on test X for each individual.
xscores	A numeric vector containing the possible score values on tests X and Y.
in2	A numeric vector with the total test scores on test Y or test A for each individual.
ascores	A numeric vector containing the possible score values on test A.

Details

Test data often consists of data at the individual level, i.e. there is a data frame, matrix or vector containing the total test score for each test taker along with other possible information about each test taker such as the total anchor test score. In order to use such data in equating, the data needs to be converted into frequencies for each score value or combination of score values. The function kefreq handles both univariate and bivariate data, resulting in a data frame that is ordered correctly for usage with the kequate function to equate two tests. In the case of univariate data, only the first two arguments should be specified. In the case of equating using an SG design, only the first score value vector should be provided since the score values are the same for the two tests. All arguments should be used for a NEAT design.

Value

A data frame containing the score values and the frequencies associated with each score value/score value combination, sorted in the manner appropriate for usage with functions glm and kequate.

Author(s)

[e-mail]
[e-mail]
[e-mail]

References

Andersson, B., Branberg, K., and Wiberg, M. (2013). Performing the Kernel Method of Test Equating with the Package kequate. Journal of Statistical Software, 55(6), 1–25. <doi:10.18637/jss.v055.i06>

See Also

table, kequate

Examples

freqdata <- data.frame(X=c(1,2,2,1,2,2,2,2,3,1,2,1,4,2,1,1,3,3,3,3), 
A=(c(0,2,1,1,0,3,1,2,2,0,2,0,3,1,1,2,2,2,1,2)))
Pdata <- kefreq(freqdata$X, 0:5, freqdata$A, 0:3)

kequate documentation built on April 13, 2022, 9:06 a.m.