STANDARDIZATION AND NORMS

• Standardization is accomplished by administering the test to a standardization sample, a group of people who represent the entire population.

  • The data collected from the standardization sample is compared against norms, which are standards of performance against which anyone who takes a given test can be compared.

• The Flynn effect supports the need to restandardize because the data indicates that the population has become smarter over the past 50 years.

RELIABILITY AND VALIDITY

• Reliability is a measure of how consistent a test is in the measurements it provides.

  • In other words, reliability refers to the likelihood that the same individual would get a similar score if tested with the same test on separate occasions (disallowing for practice effects or effects due to familiarity with the test items from the first testing).

• The two sets of scores are compared and a correlation coefficient is computed between them.

  • This is called the test-retest method.

• Validity refers to the extent that a test measures what it intends to measure.

  • Validity is calculated by comparing how well the results from a test correlate with other measures that assess what the test is supposed to predict.

• Internal validity is the degree to which the subject’s results are due to the questions being asked and not another variable.

• External validity is true validity—that is, the degree to which results from the test can be generalized to the “real world.”

TYPES OF TESTS

• Tests used in psychology can be projective tests, in which ambiguous stimuli, open to interpretation, are presented, or inventory-type tests, in which participants answer a standard series of questions.

• The Rorschach is a sequence of 10 inkblots, each of which the participant is asked to observe and then characterize.

• The TAT is a series of pictures of people in ambiguous relationships with other people.

• Power tests gauge abilities in certain areas.

• Achievement tests assess knowledge gained; the Advanced Placement exams are of this type.

• Aptitude tests, which evaluate a person’s abilities.

INTELLIGENCE

• Intelligence can be defined as goal-directed adaptive thinking.

  • Such thinking is difficult to measure on a standardized test.

• The anthropologist Francis Galton had attempted to measure intelligence by means of reaction time tests.

  • This reflects the notion that speed of processing is an essential component of intelligence.

• Alfred Binet was a French psychologist who first began to measure children’s intelligence for the French government.

  • Binet’s test measured the “mental age” of school-age children so that children needing extra help could be placed in special classrooms.

• An American psychologist and Stanford University professor named Lewis Terman modified Binet’s test to create a test commonly referred to as the Stanford-Binet Test.

• Most modern psychologists measure an aspect of intelligence, called the IQ or intelligence quotient.

• The most common intelligence tests given to children today are the Stanford-Binet Intelligence Scale and the Wechsler Intelligence Scale for Children (WISC-IV).

  • There is also a version of the Wechsler specifically geared toward adults, the Wechsler Adult Intelligence Scale (WAIS).

• In the early part of the 20th century, Charles Spearman proposed that there was a general intelligence (or g factor) that was the basis of all other intelligence.

  • Spearman used factor analysis, a statistical measure for analyzing test data.

• Robert Sternberg proposed that intelligence could be more broadly defined as having three major components: analytical, practical, and creative intelligence.

• Louis Thurstone, a researcher in the field of intelligence, posited that we need to think of intelligence more broadly because intelligence can come in many different forms.

• The most famous proponent of the idea of multiple intelligences is Howard Gardner of Harvard University.

  • Gardner has identified the following types of intelligence: verbal and mathematical (these are the two traditionally measured by IQ tests) as well as musical, spatial, kinesthetic, environmental, interpersonal (people perceptive), and intrapersonal (insightful, self-awareness).

• Daniel Goleman, a psychologist at Rutgers, has done recent work on the importance of emotional intelligence (being able to recognize people’s intents and motivations) and has created programs for enhancing one’s emotional intelligence.

• One distinction often made is between fluid intelligence and crystallized intelligence.

  • Crystallized intelligence is accumulated knowledge.

  • Fluid intelligence is the ability to process information quickly and to solve new problems.

Heredity/Environment and Intelligence

• Nature and nurture interact in the formation of human intelligence.

• One way to measure the influence of inheritance on IQ is through a heritability coefficient.

  • The heritability coefficient, also known as the heritability index, is a measure of how much an individual's traits are determined by genetics.

• Heritability is sometimes computed by comparing the IQs of identical twins who were raised separately.

HUMAN DIVERSITY

• An IQ in the 99th percentile (higher than about 135) is considered “gifted,” although there is no set standard.

• Intellectual disability refers to low levels of intelligence and adaptive behavior.

  • Intellectual disability can be categorized by severity ranging from mild, with an IQ range of 50–70, to profound, characterized by an IQ lower than 25.

• Savant syndrome is a rare phenomenon in which individuals with low IQ scores display certain specific skills at a very high aptitude.

ETHICS IN TESTING

• Those who are involved in psychometrics, or psychological testing, must be sure that they follow certain guidelines.

  • Confidentiality must be protected.

    • The purposes of the test must be clear to those administering and those taking the test.

• An issue that has received a great deal of attention in recent years is stereotype threat.

  • This occurs when a message is sent, intentionally or unintentionally, to a group of people that their group tends to perform below average on a given measure.

Next Chapter: Chapter: 13: Developmental Psychology