Validating a measure of temperament
For example, methods based on covariance matrices are typically employed on the premise that numbers, such as raw scores derived from assessments, are measurements.
Such approaches implicitly entail Stevens's definition of measurement, which requires only that numbers are assigned according to some rule.
Psychometrics is a field of study concerned with the theory and technique of psychological measurement.
As defined by the US National Council on Measurement in Education (NCME), psychometrics refers to psychological measurement.
In the late 1950s, Leopold Szondi made an historical and epistemological assessment of the impact of statistical thinking onto psychology during previous few decades: "in the last decades, the specifically psychological thinking has been almost completely suppressed and removed, and replaced by a statistical thinking.
Precisely here we see the cancer of testology and testomania of today." More recently, psychometric theory has been applied in the measurement of personality, attitudes, and beliefs, and academic achievement.
Although its chair and other members were physicists, the committee also included several psychologists.
The committee's report highlighted the importance of the definition of measurement.
Others focus on research relating to measurement theory (e.g., item response theory; intraclass correlation). Psychometricians usually possess a specific qualification, and most are psychologists with advanced graduate training.
The definition of measurement in the social sciences has a long history.
A currently widespread definition, proposed by Stanley Smith Stevens (1946), is that measurement is "the assignment of numerals to objects or events according to some rule." This definition was introduced in the paper in which Stevens proposed four levels of measurement.
Measurement of these unobservable phenomena is difficult, and much of the research and accumulated science in this discipline has been developed in an attempt to properly define and quantify such phenomena. Thurstone, Anne Anastasi, Georg Rasch, Eugene Galanter, Johnson O'Connor, Frederic M.
Critics, including practitioners in the physical sciences and social activists, have argued that such definition and quantification is impossibly difficult, and that such measurements are often misused, such as with psychometric personality tests used in employment procedures: Figures who made significant contributions to psychometrics include Karl Pearson, Henry F. Lord, Ledyard R Tucker, Arthur Jensen, and David Andrich.In addition to traditional academic institutions, many psychometricians work for the government or in human resources departments.