This is the field of study concerned with the theory and technique of psychological measurement, which includes the measurement of knowledge, abilities, attitudes, and personality traits.
An adaptation by Lewis Terman at Stanford University of Alfred Binet's original intelligence test. It measures cognitive abilities and provides an "intelligence quotient" (IQ).
This branch of psychology studies physical, cognitive and social change throughout life span. It's relevant because it deals with how people grow and develop over time - something that IQ tests like those developed by Binet aim to measure.