Nunnally's theory of measurement error

Nunnally's theory of measurement error emphasizes that when we assess things like attitudes or traits through surveys or tests, the results can be affected by errors—random mistakes or inconsistencies. These errors can come from unclear questions, distractions, or respondent fatigue, which make the measurement less reliable. Nunnally highlights that a reliable measurement minimizes these errors, ensuring the results accurately reflect the true traits being measured. Essentially, his theory underscores the importance of careful test design and implementation to produce consistent and valid assessments.