ctsem.alpha {classicaltest} | R Documentation |
Standard error of measurement (SEM)
Description
Estimates the standard error of measurement (SEM) of a scored matrix or data frame using Cronbach's alpha or the split-halves coefficient.
Usage
ctsem.alpha(x, wt = NULL, administered = NULL, maxscore = NULL)
ctsem.split(
x,
wt = NULL,
tries = 100,
seed = NA,
administered = NULL,
maxscore = NULL
)
Arguments
x |
a data frame or matrix of scored data. |
wt |
a vector with total weights. Default is |
administered |
a logical matrix indicating which items were administered.
The dimensions should be the same as |
maxscore |
a numeric value indicating which is the maximum score possible
per item. The minimum score is assumed to be 0. If |
tries |
a numeric value indicating the number of samples for the
split-halves coefficient. Default is |
seed |
a single value, interpreted as an integer, or |
Value
a list.
Examples
# No weights
ex <- correct(x = dichodata, key = dichokey, navalue = NA)
ctsem.alpha(ex)
ctsem.split(ex,tries = 5)
# With weights
set.seed(1919)
wt <- sample(x = 1:4, size = nrow(dichodata), replace = TRUE)
ctsem.alpha(ex,wt = wt)
ctsem.split(ex,wt = wt,tries = 5)