One
Introduction to Psychological Tests and Their Uses

The first and most general meaning of the term test listed in the dictionary is "a critical examination, observation, or evaluation." Its closest synonym is trial. The word critical, in turn, is defined as "relating to.a turning point or specially important juncture" (Merriam-Webster's Collegiate Dictionary, 2003). No wonder, then, that when the term psychological appears in front of the word test, the resulting phrase acquires a somewhat threatening connotation. Psychological tests are often used to evaluate individuals at some turning point or significant juncture in their lives. Yet, in the eyes of many people, tests seem to be trials on which too much depends and about which they know all too little. To a large extent, the purpose of this book is to give readers enough information about psychological tests to remove their threatening connotations and to provide the means whereby participants in the testing process and other interested parties can gain more knowledge about their specific rationale and uses. This chapter will introduce readers to the topic of psychological tests by explaining what they are, how and why they came to be, the major settings and purposes for which they are now used, and what the most important sources of information about tests and testing are.

Thousands of instruments can accurately be called psychological tests. Many more usurp the label either explicitly or by suggestion. The first objective of this book is to explain how to separate the former from the latter. Therefore, we start with the defining features that legitimate psychological tests of all types share. These features not only define psychological tests but also differentiate them from other kinds of instruments.

Psychological Tests

A psychological test is a systematic procedure for obtaining samples of behavior, relevant to cognitive, affective, or interpersonal functioning, and for scoring and evaluating those samples according to standards. A clarification of each of the main terms in this definition is vital to an understanding of all future discussion of tests. Rapid Reference 1.1 explains the meaning and rationale of all the elements in the definition of a psychological test. Unless every condition mentioned in the definition is met, the procedure in question cannot accurately be called a psychological test. It is, however, important to remember that in essence, psychological tests are simply behavior samples. Everything else is based on inferences.

Rapid Reference 1.1

Basic Elements of the Definition of Psychological Tests

Psychological tests are often described as standardized for two reasons, both of which address the need for objectivity in the testing process. The first has to do with uniformity of procedure in all important aspects of the administration, scoring, and interpretation of tests. Naturally, the time and place that a test is administered or taken, as well as the circumstances under which it is completed and the mode of administration used, can and do affect test results. However, the purpose of standardizing test procedures is to make all the variables that are under the control of the administrator as uniform as possible, so that everyone who takes the test will be taking it in a comparable way.

The second meaning of standardization concerns the use of standards for evaluating test results. These standards are most often norms derived from a group of individuals-known as the normative or standardization sample-in the process of developing the test. The collective performance of the standardization group or groups, both in terms of averages and variability, is tabulated and becomes the standard against which the performance of other individuals who take the test after it is standardized will be gauged.

Don't Forget

• The word test has multiple meanings.
• The term psychological test has a very specific meaning.
• In this book, test will be used to refer to all instruments that fit the definition of psychological test.
• Tests designed to sample skills, knowledge, or any other cognitive function will be referred to as ability tests; all others will be labeled as personality tests.
• Behavior samples themselves are complex and always reflect all aspects of a person's functioning.

Strictly speaking, the term test should be used only for those procedures in which test takers' responses are evaluated based on their correctness or quality. Such instruments always involve the appraisal of some aspect of a person's cognitive functioning, knowledge, skills, or abilities. On the other hand, instruments whose responses are neither evaluated nor scored as right-wrong or pass-fail are called inventories, questionnaires, surveys, checklists, schedules, or projective techniques, and are usually grouped under the rubric of personality tests. These are tools designed to elicit information about a person's motivations, preferences, attitudes, interests, opinions, emotional make-up, and characteristic reactions to people, situations, and other stimuli. Typically, they use questions of the multiple-choice or true-false type, except for projective techniques, which are open ended. They can also involve making forced choices between statements representing contrasting alternatives, or rating the degree to which one agrees or disagrees with various statements. Most of the time personality inventories, questionnaires, and other such instruments are of the self-report variety, but some are also designed to elicit reports from individuals other than the person being evaluated (e.g., a parent, spouse, or teacher). For the sake of expediency, and following common usage, the term test will be used throughout this book to refer to all instruments, regardless of type, that fit the definition of a psychological test. Tests that sample knowledge, skills, or cognitive functions will be designated as ability tests, whereas all others will be referred to as personality tests. Nevertheless, it is very important to remember that behavior samples are complex and always reflect the person's global functioning regardless of which aspect the test was designed to assess.

Other Terms Used in Connection With Tests and Test Titles

Some other terms that are used, sometimes loosely, in connection with tests bear explaining. One of these is the word scale, which can refer to

• a whole test made up of several parts, for example, the Wechsler Intelligence Scale for Children;
• a subtest, or set of items within a test, that measures a distinct and specific characteristic, for example, the Depression scale of the Minnesota Multiphasic Personality Inventory (MMPI);
• an array of subtests that share some common characteristic, for example, the Sequential scales of the Kaufman Assessment Battery for Children.
• a separate instrument made up of items designed to evaluate a single characteristic, for example, the Internal-External Locus of Control Scale (Rotter, 1966); or
• the numerical system used to rate or to report value on some measured dimension, for example, a Likert-type scale ranging from 1 to 5, with 1 meaning strongly disagree and 5 strongly agree.

Thus, when used in reference to psychological tests, the term scale has become ambiguous and lacking in precision. However, in the field of psychological measurement-also known as psychometrics-scale has a more precise meaning. It refers to a group of items that pertain to a single variable and are arranged in order of difficulty or intensity. The process of arriving at the sequencing of the items is called scaling.

Battery is another term often used in test titles. A battery is a group of several tests, or subtests, that are administered at one time to one person. When several tests are packaged...