Aptitude Tests

The term aptitude, according to most dictionaries, is derived from the Latin term aptitudo, meaning fitness. The psychological use of the term is similar in that it has traditionally referred to a potential for acquiring knowledge or skill. Traditionally, aptitudes are described as sets of characteristics that relate to an individual's ability to acquire knowledge or skills in the context of some training or educational program. There are two important aspects of aptitude to keep in mind. First, aptitudes are present conditions (i.e., existing at the time they are measured). Second, there is nothing inherent in the concept of aptitudes that says whether they are inherited or acquired or represent some combination of heredity and environmental influences. Also, aptitude tests do not directly assess an individual's future success; they are meant to assess aspects of the individual that are indicators of future success. That is, these measures are used to provide a probability estimate of an individual's success in a particular training or educational program. While the meaning of aptitude is well delineated, there is much controversy over how to distinguish aptitude tests from other kinds of psychometric measures, specifically intelligence and achievement tests, partly because the major salient difference between intelligence, aptitude, and achievement tests has to do with the purpose of testing rather than with the content of the tests. What makes an assessment instrument an aptitude test rather than an intelligence or achievement test is mainly the future orientation of the predictions to be made from the test scores.

Historians generally date the movement of modern psychological testing from the 1905 work by Alfred Binet and Théodore Simon in developing a set of measures to assess intelligence. The Binet-Simon measures, and especially the English translation and refinement made by Lewis Terman in 1916, called the Stanford-Binet, are in widespread use even today. Few adults living in industrialized countries today have avoided taking at least one test of intelligence during their school years. Intelligence tests were designed with the goal of predicting school success. [Page 40]Thus, in terms of the definition of aptitude provided above, when the purpose of an intelligence test is prediction, then the intelligence test is essentially an aptitude test—although an aptitude test of general academic content (e.g., memory, reasoning, math, and verbal domains). Aptitude tests, however, sample a wider array of talents than those included in most general intelligence measures, especially in the occupational domain. By the late 1910s and early 1920s, dozens of different aptitude tests had been created for prediction of success in a variety of different occupations (e.g., auto mechanic, retail salesmen, waitress, telegrapher, clerk, Hollerith operator, musician, registered nurse).

It is important to distinguish between so-called trade tests and aptitude tests. The distinction rests more on the characteristics of the examinee population than on the content of the tests. That is, when all the examinees can be expected to have similar prior exposure to the knowledge and skills needed to perform well on the test, the test is essentially one of ability or aptitude. But when prior knowledge and skills have an important impact on the examinees' success on the test, it is essentially an achievement test, or a measure of learned knowledge or skills, rather than an assessment of potential for acquiring such knowledge or skills. For psychologists who design aptitude tests, this is a critical concern. For example, the psychologist must be able to determine whether reading skills are an important determinant of test performance in order to present the test material in a paper-and-pencil format. Intelligence test developers assumed that individual differences in reading skills in young children were possible confounding influences, and so the developers created intelligence tests that did not require a child to know how to read or write. For assessing the aptitude of adults for an office clerk job, however, being able to read would be a prerequisite skill, so a paper-and-pencil aptitude test would certainly be appropriate.

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