Section 1 lists the characteristics that useful tests have: reliability, validity, and standardization. A test is considered reliable when it consistently yields the same results under a variety of circumstances. Measuring a test's ability to predict performance can assess validity. To be standardized, a test must be administered and scored the same way every time and they must have established norms. Most psychologists use the percentile system to transform raw scores into figures that reflect comparisons with other test takers.

Section 2 describes theories of intelligence and the major intelligence tests. Different theories of intelligence presented in this section include the two-factor theory, L.L. Thurstone's theory, Howard Gardner's theory of multiple intelligence, and Robert Sternberg's theory. Two major intelligence tests are the Stanford-Binet and the Wechsler tests. IQ tests seem to be most useful when related to school achievement, but debates about the effect of environment and heredity on IQ test performance still arise. Critics argue that IQ tests have a cultural bias.

Section 3 reviews tests that are designed to measure achievement, abilities, and interests. Aptitude tests aim to discover a person's talents and to predict how well he or she will be able to learn a new skill. Achievement tests measure how much a person has already learned in a particular area. Interest tests, which are used to help people choose careers, try to determine a person's preferences, attitudes, and interests.

Section 4 describes types of personality tests and demonstrates how they are used to assess characteristics, identify problems, and predict behavior. The tests can be objective, such as the Minnesota Multiphasic Personality Inventory (MMPI), or projective, such as the Rorschach inkblot test and the Thematic Apperception Test (TAT).