Psychometrics is a field of study concerned with the theory and technique of
psychological measurement. One part of the field is concerned with the objective
measurement of skills and knowledge, abilities, attitudes, personality traits, and
Human interactions: relationships, feelings, attitudes, loyalties, perceptions and
engagements do not yield easily to numeric quantification.
L.L. Thurstone. 1959. The Measurement of Values. Chicago & London: The University
of Chicago Press