Psychometrics

Psychometrics is a field of study concerned with the theory and technique of psychological measurement. As defined by National Council on Measurement in Education (NCME), psychometrics refers to psychological measurement. Generally, it refers to the field in psychology and education that is devoted to testing, measurement, assessment, and related activities. One part of the field is concerned with the objective measurement of skills and knowledge, abilities, attitudes, personality traits, and educational achievement. For example, some psychometric researchers have, thus far, concerned themselves with the construction and validation of assessment instruments such as questionnaires, tests, raters' judgments, and personality tests. Another part of the field is concerned with statistical research bearing on measurement theory (e.g., item response theory; intraclass correlation).

As a result of these focuses, psychometric research involves two major tasks: (i) the construction of instruments; and (ii) the development of procedures for measurement. Practitioners are described as psychometricians. Psychometricians usually possess a specific qualification, and most are psychologists with advanced graduate training. In addition to traditional academic institutions, many psychometricians work for the government or in human resources departments. Others specialize as learning and development professionals.

Psychological testing has come from two streams of thought: the first, from Darwin, Galton, and Cattell on the measurement of individual differences, and the second, from Herbart, Weber, Fechner, and Wundt and their psychophysical measurements of a similar construct. The second set of individuals and their research is what has led to the development of experimental psychology, and standardized testing.

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