Individual assessment involves the measurement of individual differences. I-O psychologists perform individual assessments in order to evaluate differences among candidates for employment as well as differences among employees. The constructs measured pertain to job performance. With candidates for employment, individual assessment is often part of the personnel selection process. These assessments can include written tests, physical tests, psychomotor tests, personality tests, work samples, and assessment centers.
Psychometrics is the science of measuring psychological variables, such as knowledge, skills, and abilities. I-O psychologists are generally well-trained in psychometric psychology.