The sophisticated measurement of human personality inescapably depends on the use of a variety of concepts to provide trait definitions and entails the application of various methods of observation & evaluation. Personality theorists and researchers seek to define & to understand the diversity of human traits, the many ways people have of thinking & perceiving and learning & emoting. Such nonmaterial human dimensions, types, & attributes are constructs-in this case, inferences drawn from observed behavior. Personality assessment, the measurement of personal characteristics. Assessment is an end result of gathering information intended to advance psychological theory & research & to increase the probability that wise decisions will be made in applied settings.The approach taken by the specialist in personality assessment is based on the assumption that much of the observable variability in behavior from one person to another results from differences in the extent to which individuals possess particular underlying personal characteristics. The assessment specialist seeks to define these traits, to measure them objectively, & to relate them to socially significant aspects of behavior.