subkoviak: Calculate Subkoviak's (1988) single administration...

In rcrtan: Criterion-Referenced Test Analysis

Description

Calculate Subkoviak's (1988) single administration consistency indices

Usage

subkoviak(data, items, raw_cut_score, total = NULL, look_up = FALSE)

Arguments

data	A data frame of dichotomously scored test items
items	Raw column indices representing the test items or number of items on the test (see Details)
raw_cut_score	The raw cut-score for the test
total	Total score column of the test (see Details)
look_up	If TRUE, the agreement and kappa tables from Subkoviak (1988) are returned with the results

Details

When the item-level information is available, Kuder-Richardson 20 is used as an estimate of alpha. If only the total scores on the test are available and the number of items is known, Kuder-Richardson 21 is used as an estimate of alpha.

Value

The z_cut score and the rounded z_cut_rounded score for the test

The estimated alpha coefficient. K-R21 is used when there is no item-level information. Otherwise, K-R20 is used.

The rounded values for the agree_coef (agreement) and kappa_coef (kappa) coefficients from Subkoviak's (1988) tables

Examples

subkoviak(data = bh_depend, items = 2:31, raw_cut_score = 21)

Example output

     z z_rounded    KR_est agree_coef.r_0.9 kappa_coef.r_0.9
1 0.66       0.7 0.8613709             0.89              0.7

rcrtan documentation built on May 2, 2019, 2:10 a.m.