Further discussion on reliability: the art of reliability estimation.
Sijtsma and van der Ark (2015) focused in their lead article on three frameworks for reliability estimation in nursing research: classical test theory (CTT), factor analysis (FA), and generalizability theory. We extend their presentation with particular attention to CTT and FA methods. We first consider the potential of yielding an overly negative or an overly positive assessment of reliability based on coefficient alpha. Next, we discuss other CTT methods for estimating reliability and how the choice of methods affects the interpretation of the reliability coefficient. Finally, we describe FA methods, which not only permit an understanding of a measure's underlying structure but also yield a variety of reliability coefficients with different interpretations. On a more general note, we discourage reporting reliability as a two-choice outcome--unsatisfactory or satisfactory; rather, we recommend that nursing researchers make a conceptual and empirical argument about when a measure might be more or less reliable, depending on its use.
Yanyun Yang, PhD, is Associate Professor, Department of Educational Psychology and Learning Systems, Florida State University, Tallahassee. Samuel B. Green, PhD, is Professor, T. Denny Sanford School of Social and Family Dynamics, Arizona State University, Tempe.
Yanyun
Y
Yang
Samuel B
SB
Green
D006801:Humans; D015233:Models, Statistical; D015399:Nursing Research; D015203:Reproducibility of Results