get_cronbach {COINr}

Cronbach's alpha

Description

Calculates Cronbach's alpha, a measure of statistical reliability. Cronbach's alpha is a simple measure of "consistency" of a data set, where a high value implies higher reliability/consistency. The selection of indicators via get_data() allows to calculate the measure on any group of indicators or aggregates.

Usage

get_cronbach(coin, dset, iCodes, Level, ..., use = "pairwise.complete.obs")

Arguments

coin

A coin or a data frame containing only numerical columns of data.

dset

The name of the data set to apply the function to, which should be accessible in .$Data.

iCodes

Indicator codes to retrieve. If NULL (default), returns all iCodes found in the selected data set. See get_data().

Level

The level in the hierarchy to extract data from. See get_data().

...

Further arguments passed to get_data(), other than those explicitly specified here.

use

Argument to pass to stats::cor to calculate the covariance matrix. Default "pairwise.complete.obs".

Details

This function simply returns Cronbach's alpha. If you want a lot more details on reliability, the 'psych' package has a much more detailed analysis.

This function replaces the now-defunct getCronbach() from COINr < v1.0.

Value

Cronbach alpha as a numerical value.

Examples

# build example coin
coin <- build_example_coin(up_to = "new_coin", quietly = TRUE)

# Cronbach's alpha for the "P2P" group
get_cronbach(coin, dset = "Raw", iCodes = "P2P", Level = 1)