A practical use for the KR-21 reliability coefficient.
KR-21 provides a lower limit for the computed value of KR-20. KR-20 is equivalent to coefficient alpha when a test is composed of dichotomous items scored 0 or 1. Therefore, KR-21 coefficients, computed from simple summary statistics, can be used in cases in which journal authors do not provide the test score reliability. Use of KR-21 in these cases will provide the reader with a lower limit for the value of KR-20.
Charter
Richard A
RA
MH Group/Mental Health (06/116B), Department of Veterans Affairs, VA Long Beach Healthcare System, 5901 East Seventh Street, Long Beach, CA 90822, USA.
D006801:Humans; D011581:Psychological Tests; D015203:Reproducibility of Results