If you are a student on a budget, use your library’s interlibrary loan or the Internet Archive. If you are a professional, buy the 3rd edition used or invest in the chapter-specific PDFs.
Jum C. Nunnally’s Psychometric Theory is considered a foundational "Citation Classic" in the behavioral sciences, specifically designed to bridge the gap between highly technical journal methods and the practical needs of graduate researchers. The text is most famous for establishing rigorous standards for measuring latent traits psychometric theory nunnally pdf
While Cronbach mathematically invented alpha, Nunnally popularized it. He provided the rules of thumb for interpreting alpha: If you are a student on a budget,
: The consistency of a measure. Nunnally is famously associated with the rule of thumb that a Cronbach’s alpha is the minimum acceptable level for early-stage research. Nunnally is famously associated with the rule of
For those entering the field, a strong grasp of these theories is essential, whether pursuing a career as a psychometrist or a clinical psychologist. (PDF) Psychometrics - ResearchGate
