Psychometrics is the field of study concerned with the theory and technique of educational measurement and psychological measurement, which includes the measurement of knowledge, abilities, attitudes, and personality traits. The field is primarily concerned with the construction and validation of measurement instruments, such as questionnaires, tests, and personality assessments.
It involves two major research tasks, namely: (i) the construction of instruments and procedures for measurement; and (ii) the development and refinement of theoretical approaches to measurement. Those who practice psychometrics are known as psychometricians and although they may also be clinical psychologists, they are not obliged to be so and could instead be (for example) human resources or learning and development professionals. Either way specific, separate, qualifications in psychometrics are required.
Psychometricians develop, administer, and score tests and exams. They use mathematical techniques to evaluate the large sets of data from tests. They use techniques such as factor analysis, multidimensional scaling, and data clustering. School districts and test publishers often employ psychometricians.