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Chapter 3 Lesson 6: Operational Definitions In Lesson 5, it was stated that adequate evidence must be collected to test a claim such as "antidepressant medications reduce the symptoms of major depression." But how do we know when evidence is adequate? The remaining lessons will all, in one way or another, attempt to answer this very difficult question. In the present lesson, we will begin constructing an answer by addressing the following question: what are the specific meanings of the terms ("concepts") in a claim? This is an important question because the evidence we collect in testing a claim will depend, in part, on the meaning of the concepts it uses. For example, in order to collect evidence that can test the claim about antidepressant medications, we need to know what is meant by the concept "major depression." A concept is a generalized idea of a category of events. In other words, a concept is a term that represents a group of actual objects or situations. For instance, the word "desk" is a concept that refers to objects that have legs and on which one writes, draws, or reads. It differs from the concept "table," which refers to objects that have legs and on which one performs a number of functions (such as eating, playing games, and so on). It is very difficult to express in words exactly how desks and tables differ from one another, especially given the fact that one can eat on desks and can write or read on tables. Nevertheless, in everyday life we rarely get confused by these two concepts: a group of people usually can agree on which objects are desks and which objects are tables. What about the concepts we use in psychology? There are two difficulties with psychological concepts that may cause confusion when trying to test a claim. First, unlike concepts referring to physical objects such as desks and tables, psychological concepts such as "stress" and "intelligence" refer to unobservable mental phenomena. We make inferences about these concepts by observing people's behavior (and other directly observable events). For example, we can infer something about the intelligence of people by observing their scores on IQ tests. Second, a particular psychological concept may mean different things to different researchers. This has been a problem with use of the term "stress": As your book notes, some have viewed stress as a stimulus event that presents difficult demands (a divorce, for instance), while others have viewed stress as the response of physiological arousal elicited by a troublesome event. It should be obvious that researchers who use the same term to refer to what are actually different concepts would not be understood by each other. Operational Definitions of Concepts Because of the difficulties mentioned in the previous paragraph, we need to carefully define the concepts we use when making a claim in psychology. Because science is "empirical" (that is, science is based on direct observations of nature), the definitions of scientific concepts must involve events in the natural world that can be measured directly. Such definitions are called "operational definitions." An operational definition refers to a set of observable measurements that give meaning to a concept. For example, we may operationally define the concept of "temperature" as the readings on a thermometer rather than our subjective feelings of hot, warm, cool, and cold. As another example, we may operationally define the concept of "intelligence" as scores on a particular IQ test rather than a subjective impression of how bright or dull a person seems to be. Thus, there are two advantages to using operational definitions. (1) By operationally defining our concepts, we can be certain that all researchers who make use of the same operational definition will be studying the same thing. (2) Operational definitions prevent subjective impressions from influencing our observations. The claim that "life changes are a form of stress" was mentioned in the textbook. The meaning of the concept of "stressful life changes" is one that probably would differ widely among different researchers; and its measurement could be influenced by subjective biases. Thus, in order to make sure that different researchers are studying the same thing, and studying it in an objective manner, an operational definition of the concept had to be developed. One operational definition of the concept of "stressful life changes" is "score on the Social Readjustment Rating Scale" (SRRS). By linking various life changes with particular numerical values related to the amount of stress, the SRRS provides an objective measure of stress. Problems With Operational Definitions Although operational definitions help us to avoid some important problems, their use introduces other problems. The major problem introduced is that a particular operational definition may measure other concepts in addition to the one we wish to measure. This is a problem mentioned in conjunction with the SRRS. It was noted in the textbook that, because the SRRS contains a larger number of negative than positive life changes, scores on the scale may be measuring frustration in addition to change. This makes it difficult to interpret the results of research that makes use of the SRRS. Let's look at another example of this problem. The concept of "knowledge of the material in this course" (that is, the one you are taking right now) may be operationally defined as "the average score on five multiple-choice tests." This seems to be a straightforward way to measure knowledge of course material. But this operational definition may be measuring concepts other than simply knowledge. Here is a partial list of possibilities: level of test anxiety, verbal comprehension, reading rate, distractibility (especially if there are frequent disturbances occurring in the room during tests), and "test wiseness" (strategies you have learned for taking multiple-choice tests). Thus, one person may get a low score because he becomes very anxious whenever he is tested. Another may get a low score because she was distracted by the student next to her who kept tapping a pencil. A third person may get a low score because he is a slow reader and the test had a time limit. And so on. In none of these cases is lack of knowledge necessarily the cause of the person's low score. In order to minimize this problem, researchers may use a variety of operational definitions when they are trying to measure a concept. Although each operational definition will tend to measure concepts other than the one being studied, the concepts measured will tend to differ from one operational definition to the next. For example, a teacher who wants to get a good estimate of the amount of knowledge each student acquires in a course will use a variety of measurements: multiple-choice tests, essay tests, short quizzes, research papers, oral reports, class participation, reaction papers, and so one. Each operational definition has weaknesses; but, when considered together, they should give a good idea of how much each student has learned. Testable Claims Require Operationally Defined Concepts If we are unable to develop an operational definition of one or more major concepts in a claim, then the claim is untestable. That is, in order to test a claim, its concepts must be linked to observable events that can be measured. With some ingenuity, most concepts can be operationally defined in ways that many people would accept. But there are some concepts that cannot be operationally defined because there simply are no observable events that can be linked to them. For example, it would be very difficult to operationally define concepts such as "virtue" or "freedom": these concepts are so complex and abstract that there seems to be no specific observations to which they could be linked. Similarly, one could not operationally define supernatural events: by definition, they are beyond our ability to observe. Although some people claim that supernatural events have effects in the natural world that might be observable, it is impossible to be certain that the cause of these natural events was something that occurred in a supernatural realm (but see Vuletic, 1997). The main point you should remember is this: any claim mentioning a particular concept cannot be tested until that concept has been operationally defined. Critical Thinking Questions Question 6-1 Social anxiety refers to feeling anxious about being in particular social situations, such as speaking in public, going to parties, and so on. Here is a description of social anxiety from the Social Phobia/Social Anxiety Association web site: In public places, such as work, meetings, or shopping, people with social anxiety feel that everyone is watching, staring, and judging them (even though rationally they know this isn't true). The socially anxious person can't relax, "take it easy", and enjoy themselves in public. In fact, they can never fully relax when other people are around. It always feels like others are evaluating them, being critical of them, or "judging" them in some way. The person with social anxiety knows that people don't do this openly, of course, but they still feel the self-consciousness and judgment while they are in the other person's presence. It's sometimes impossible to let go, relax, and focus on anything else except the anxiety and fear. Because the anxiety is so very painful, it's much easier just to stay away from social situations and avoid other people altogether. Develop your own operational definition of social anxiety. Make sure that your operational definition of social anxiety allows you to distinguish it from problems associated with other emotions, such as anger or depression. Suggested Answer Question 6-2 A question sometimes asked by people is, "can computers think?" In order to answer this question scientifically, we would need to measure the ability to think. Develop an operational definition of "thinking" that might allow you to answer the question about "thinking computers." Suggested Answer Question 6-3 Which of the following claims are testable and which are untestable? Stealing is immoral. "Slips of the tongue" are expressions of unconscious desires. Murderers have a mental disorder. Murderers are evil. Most people have some psychic ability. Lester loves Viola. Ghosts are the spirits of deceased individuals. Sugary drinks improve memory for factual information Brain activity causes mental activity Question 6-4 A study investigating alcohol use in young people stated that "44 percent of students on college campuses can be classified as binge drinkers." Binge drinking in males was operationally defined as "five or more drinks on one occasion," whereas binge drinking in females was operationally defined as "four or more drinks on one occasion." Think carefully about these operational definitions and discuss whether or not you agree that 44% of college students should be labeled as "binge drinkers." Suggested Answer Bibliography and References Liebowitz Social Anxiety Scale. (u.d.). Retrieved March 13, 2002, from http://www.psychmeds.com/liebowitz.html Seavey, T. (March 27, 2002). Mobocracy, the skeptical environmentalist, and statistics. Health Facts and Fears.com. Retrieved March 27, 2002, from http://www.healthfactsandfears.com/editors_rants/objectivity/2002/mobocracy031202.ht ml Social Phobia/Social Anxiety Association. (u.d.). Retrieved March 13, 2002, from http://www.socialphobia.org/ Stanovich, K. E. (2001) How to think straight about psychology (6th ed.). New York: Longman. Turing, A. (1950). Computing machinery and intelligence. Mind, 59, 433-460. Vuletic, M. I. (1997). Methodological naturalism and the supernatural. Retrieved March 13, 2002, from http://www.infidels.org/library/modern/mark_vuletic/ntse.html