Coefficient alpha and the reliability of composite measurements.

摘要: Following a general approach due to Guttman, coefficientα is rederived as lower bound on the reliability of test. A necessary and sufficient condition under which equality attained in this inequality hence thatα equal test derived shown be closely related recent redefinition concept parallel measurements Novick. This then also unit rank assumption originally adopted by Kuder Richardson derivation their formula 20. The later Jackson Ferguson one Gulliksen are here. It pointed out that statement “coefficientα mean split-half reliabilities” true only restricted assumed Cronbach body his result. Finally some limitations uses any function ofα measure internal consistency noted.