ScaleCalc {CMO}R Documentation

Calculates scale raw scores by recoding and aggregating test item values

Description

Calculates a scale raw score by summarizing test item values concerning a question of interest. Test items are first recoded to conform their correlation to the question of interest. Integration of test items is done either by sum or mean.

Usage

ScaleCalc(mat, polungsVek, calcMethod = "mean", recodeMethod = "maxminus", maxVal = 100, nBootRep = 0)

Arguments

mat numeric matrix of test item scores
polungsVek recode scheme foreach test item, depicted by "+" or "-" signs
calcMethod method to integrate the recoded test item values; either sum or mean
recodeMethod method to recode the test item values by the recoding scheme; either maxminus, minus
maxVal maximal test item value (default = 100)
nBootRep number of bootstraps to perform

Value

returns a list of class Berechnungsvorschrift

rawItemScores test item raw data
polungVek character vector depicting the recoding scheme
recodeMethod recoding method
calcMethod method used to integrate the test item values
maxVal maximum score per test item values
recItemScores recoded test item scores
rawScores itegrated scale raw score

and all items Cronbach's alpha scores as calculated by the function mcron

Author(s)

Christian Montel

See Also

mcron

Examples

#create some arbitrary test results
data <- matrix(ceiling(runif(400)*100),nrow=20)
#create some question of interest result
erg <- ceiling(runif(20)*100)
polung <- apply(data,2,function(x) if (cor.test(erg,x)$estimate < 0)
return("-") else return("+"))
str(ScaleCalc(data,polungsVek=polung))

[Package CMO version 1.02 Index]