Psychometrics is a field of statistics concerned with measurement and assessment and tends to be associated with quantitative psychology, education, and other social sciences.
One of the central activities associated with psychometrics is creating high-quality surveys, direct assessments, and other tools that can reliably and accurately measure some construct(s) of interest. These tend to be latent variables, or constructs that cannot be directly measured. This might include creating and validating a test of a child’s early literacy ability, or it might include creating and validating a survey measuring adults’ personality factors.