guttman_l2: Guttman's Lambda_2 (L2) Reliability Coefficient
In zief0002/QME: Classic test theory item analysis

Description Usage Arguments Details Value Author(s) References Examples

This function estimates the reliability coeffcient based on Guttman's Lambda_2.

1	guttman_l2(x, ...)

`x`	is a data frame or matrix of the keyed items (0/1)

This computation is based on Guttman's second lower bound for reliability (Guttman, 1945).

Returns a list with the estimate (l2), lower (ll) and upper (ul) confidence limits, and standard error of measurment (sem)

University of Minnesota, Educational Psychology Computing Club

Guttman, L. (1945). A basis for analyzing test-retest reliability. Psychometrika, 10 (4), 255–282.

#Load the test responses and the answer key
data(math)
data(math_key)

#Put test and key into a QMEtest object
myTest = QMEtest(math, math_key)

#Key the test and output as a data frame without IDs
keyedTest = getKeyedTestNoID(myTest)

#Compute Guttman's L2
guttman_l2(keyedTest)