reliability {conogive}

Calculate the Ordinal Reliabiltiy

Description

The function ordinal_r calculates the concrete ordinal reliability. The functions theoretical_ordinal_r and theoretical_ordinal_alpha calculates the theoretical ordinal reliability and alpha based on the polychoric correlation matrix.

Usage

ordinal_r(
  object,
  xi = c("sample", "theoretical"),
  weights = c("optimal", "equal")
)

theoretical_ordinal_r(object, weights = c("optimal", "equal", "sigma"))

theoretical_ordinal_alpha(object)

Arguments

object

An object of class conogive.

xi

How to calculate the Xi matrix. Option "theoretical" calculates the theoretical Xi matrix from rho, while "sample" calculates the sample Xi matrix.

weights

The weights used to calculate the ordinal reliability. Option "optimal" uses the optimal weights and "equal" the equal weights.

Details

The population value of theoretical ordinal alpha equals the theoretical ordinal reliability when the underlying multivariate normal is parallel. The concrete ordinal reliability is the sqaured correlation between the true latent variable and the best linear predictor of the observed Likert-type data. See ((ref)) for definitions.

Value

The concrete ordinal reliability, theoretical ordinal reliability, or theoretical ordinal alpha.

Examples

if(require("psychTools")) {
  agreeableness = psychTools::bfi[c("A1", "A2", "A3", "A4", "A5")]
  agreeableness[, "A1"] = 7 - agreeableness[, "A1"] # Reverse-coded item.
  object = conogive(agreeableness)
  ordinal_r(object, weights = "equal") # 0.6394087
  theoretical_ordinal_alpha(object) # 0.7589922
  theoretical_ordinal_r(object, weights = "equal") # 0.7689878
  ordinal_r(object, weights = "optimal") # 0.6763742
  theoretical_ordinal_r(object) # 0.8101108
}