.cronbachs {quest}

Bootstrap Function for cronbachs() Function

Description

.cronbachs is the function used by the boot function within the cronbachs function. It is primarily created to increase the computational efficiency of bootstrap confidence intervals within the cronbachs function by doing only the minimal computations needed to compute cronbach's alpha for each set of variables/items.

Usage

.cronbachs(dat, i, nm.list, use)

Arguments

dat

data.frame of data. It can contain variables other than those used for cronbach's alpha calculation.

i

integer vector of length = nrow(dat) specifying which rows should be included in the computation. When used by the boot::boot function this argument will change with every new bootstrapped resample.

nm.list

list of character vectors specifying the sets of variables/items associated with each of the cronbach's alpha calculations.

use

character vector of length 1 specifying how missing data should be handled when computing covariances. See cov for details.

Value

double vector of length = length(nm.list) providing cronbach's alpha for each set of variables/items.

Examples

dat0 <- psych::bfi[1:250, ]
dat1 <- str2str::pick(x = dat0, val = c("A1","C4","C5","E1","E2","O2","O5",
   "gender","education","age"), not = TRUE, nm = TRUE)
vrb_nm_list <- lapply(X = str2str::sn(c("E","N","C","A","O")), FUN = function(nm) {
   str2str::pick(x = names(dat1), val = nm, pat = TRUE)})
.cronbachs(dat = dat1,
   i = sample(x = 1:nrow(dat1), size = nrow(dat1), replace = TRUE),
   nm.list = vrb_nm_list, use = "pairwise")