Description Usage Arguments Details Value References Examples
Cronbach's alpha measures how correlated are the items in a test
1 | alpha.cronbach(test)
|
test |
a matrix or a Dataframe that holds the test response data |
the coefficient is calculated
α = (n/n-1)*(1 - (∑ V_i/V_t))
where $V_t$ is the variance of test scores and $V_i$ is the variance of item scores. It is desirable that the items are closely interrelated (coefficient near 1). This function was extracted from multilevel_2.5 package.
Cronbach's alpha for the test and the number of individuals of test.
Cronbach L. J. (1951) Coefficient Alpha and the internal structure of tests. Psychometrika, 16,297-334
1 2 | data <- simulateTest(model="2PL",items=10,individuals=1000)
alpha.cronbach(data$test)
|
Add the following code to your website.
For more information on customizing the embed code, read Embedding Snippets.