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Ch. 1. Introduction
I. Definition
A Measurement: systematic assignment of numbers to the characteristics of objects.
B. Psychometrics: theories concerning psychological measurement.
II. History of testing and measurement (A History of Psychological Testing, by Philip H. Du
Bois (1970))
A. About 1000 B.C. China had a testing system for civil-service officers (music,
horsemanship, civil law, writing, Confucian principles, and knowledge of public
and private ceremonies). In 1905, China eliminated the system.
B. Francis Galton (1822-1911): Anthropometric Lab had Galton's test which
contained various sensory and motor skills. Regression (1885).
C. Karl Pearson (1857-1936): Pearson product moment correlation coefficient and
chi-square test, r (1895).
D. Alfred Binet (1857-1911): First individual intelligence test (1905).
E. William Stern (1871-1938): developed the concept of Intelligence Quotient (IQ)
which was the ratio of mental (measured) age to chronological (actual) age.
F. Charles Spearman (1863-1945): modern concept of reliability and factor analysis.
G. Many journals were founded: Psychometrika (1935), Educational and
Psychological Measurement (1941), British Journal of Mathematical and
Statistical Psychology (1947), Multivariate Behavioral Research (1966).
III. Probability Review
A. Expected value (Mean): Sum [pro(x)*value(x)]
E(X) = Σp(X = xi)xi = μX
E(XY) = ΣΣp(X = xi, Y = yj)xiyj = E(X)E(Y)
E(X²) = Σp(X = xi)xi²
B. Expectation Rules (X and Y are independent)
1. E(c) = c, where c is a constant.
2. E(cX) = cE(X)
3. E(X + Y) = E(X) + E(Y)
4. E(XY) = E(X)E(Y)
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