test_length: New test length

In cddesja/hemp: Handbook of Educational Measurement and Psychometrics Using R Companion Package

Description

Calcuate the length of a test given a desired reliability.

Usage

test_length(data, r, r_type)

Arguments

data	A data frame
r	The desired reliability
r_type	Either "alpha" for coefficient alpha,"split" for split-half reliability, or a numeric value given the current reliability calculated elsewhere. The "split" type assumes an even/odd split with the Spearman-Brown correction.

Value

The length of a test given the desired reliability

Examples

data(SAPA)
test_length(SAPA, r = .95, r_type = "split")
test_length(SAPA, r = .95, r_type = "alpha")
test_length(SAPA, r = .95, r_type = .90)
test_length(SAPA, r = .85, r_type = .90)

cddesja/hemp documentation built on April 7, 2021, 9:24 p.m.