Intelligence Tests

An intelligence test is a structured situation designed to elicit information about the cognitive abilities of an individual. The test may be administered individually or in a group. There are certain advantages to having a test administered to a person one-on-one with a trained examiner, typically a school psychologist. No reading need be required on the part of the examinee, so it is possible to test young children and people of limited literacy. And an empathic and perceptive examiner can maintain a continuing high level of motivation on the part of the examinee. [Page 549]Furthermore, the examiner can observe aspects of the examinee's behavior in the testing session that are not reflected in the numerical score but that would assist in diagnosis. On the other hand, individual testing is expensive—prohibitively so if information is desired on each child in a school or on each applicant for admission to an educational institution or a training program. Primarily because of cost considerations, most ability testing has become group testing, using paper-and-pencil or computer-administered testing instruments that can be scored objectively.

Scores on intelligence tests are normally distributed in large populations and are usually reported on a scale in which 100 indicates average intelligence. Scores are scaled so that about the top 16% of the population will receive scores of 115 or above, the top 2.5% will receive scores of 130 or above, the bottom 16% will receive scores of 85 or below, and the bottom 2.5% will receive scores of 70 or below. The majority of people—68% of the population—will have scores clustered around 100, ranging from 85 to 115.

The typical intelligence test will have a variety of items designed to tap different aspects of the person's cognitive abilities. Some of the items may ask for specific pieces of information, such as how many years there are in a decade or how much change a person would receive if he or she bought an article of clothing costing $18.67 and gave the clerk a $20 bill. Other questions might ask about objects missing or out of place in a picture; still others would be tests for memory, such as repeating back a list of five digits that has been read aloud, or tests of reasoning, such as finding the right pattern piece to complete a design. In an individually administered test, the examiner asks each question, records the answer, and makes a judgment as to the answer's correctness or quality. Testing stops when the examinee has failed to answer a specified number of questions correctly. When the test is administered to a group, the questions are often in multiple-choice format, and responses are usually recorded by filling in bubbles on an answer sheet. Answers are compared to a key, so judgment as to correctness is avoided.

Studies repeatedly reveal a link between scores on tests of intelligence and educational achievement. Those with higher test scores typically receive higher scores on standardized tests of academic achievement, earn higher grades in school, and complete more years of education. Research also shows a moderate association between intelligence test scores and job status and occupational success.

...