the scientific field concerned with the theory and practice of measuring psychological constructs—such as personality traits, cognitive abilities, attitudes, emotions, or other latent variables. It involves designing, testing, and validating measurement instruments (e.g., questionnaires, tests, and rating scales) to ensure they assess these constructs in a reliable and valid manner. Psychometrics underpins the development of standardized assessments used in research, education, and clinical settings.
Example
A research team developing a new questionnaire to assess fatigue in people with rheumatic conditions uses psychometric methods—such as factor analysis and reliability testing—to ensure the tool accurately measures fatigue across different populations and produces consistent results over time.