Operational definition
An operational definition is a statement that describes how a particular variable is to be measured, or how an objector condition is to be recognized. Operational definitions tell you what to do or what to observe. (The word “operational” means “describing what to do.”)
Operational definitions need to be clear and precise so that a reader knows exactly what to observe or measure.
Constructs:
A construct is an obstruction that cannot be observed directly. It is a concept inverted to explain behaviour. i.e. Intelligence, personality, teacher effectiveness, creativity, ability, achievement and motivation etc. To be measurable construct must be operationally defined. It is define in terms of operation of process that can be observed and measured. To measure a construct it is necessary to identify the scores of values it can assume. For example- the construct “personality” can be made measurable by defining two personality types, introverts and extroverts, as measured by scores on a 30-items questionnaire, with a high score indication a more introverted personality and a low score indicating a more extroverted personality. Similarly, the construct “teacher effectiveness” may be operationally defined by observing a teacher in action and judging effectiveness based on four levels: unsatisfactory, marginal, adequate, and excellent. When constructs are operationally defined, they become variables,
What to Do: Writing Operational Definitions
· Write an operational definition for each variable on your list of independent and dependent variables.
· Write an operational definition for each term (such as greater than, less than, increased, and significant) used to indicate the nature of the relationship between variables.
· For each definition you write, ask yourself:
• Are the rules and procedures for measuring the variables clear?
• Have mutually exclusive and totally inclusive categories for the variables been established?
• Is the standard of comparison clear for each term?
· Look over the written plan for carrying out an investigation, or write up a plan.
· Identify and list any variables or terms that do not have a single, clear, obvious meaning.
· If there are several reasonable ways to make an observation or to perform an action, choose one that suits the purpose of the investigation.
· Write a clear, complete definition of what the researcher should do or measure. Check your definition by asking yourself, Will this definition tell another person what to observe or how to measure? If necessary, revise your definition before starting your investigation
Distinguishing Operational Definitions, Variables, And Values
Throughout this book we will be referring to psychological variables. Some students do not have a grasp of the simple term variable, so this might be a good time to clarify the concept. A variable is some characteristic of the world that can vary or change. It is something that can be measured or detected. Therefore operational definitions , which define a word by telling how to measure or detect something, always define a variable.
Variables are distinct from values -numbers or scores. Variables can take on many possible values, depending on what is measured. The following table shows examples of variables, operational definitions, and values.
The last definition in the table (number of hairs on the left thumb) reminds us that operational definitions are not always good or valid. They are simply descriptions of measurement actions. We would argue that the last definition is an operational definition. It implies a set of measurement operations (look at left thumb, count hairs) but it is not a good definition if you want to measure intelligence. The second and third definitions also are poor because they are poorly specified (which questionnaire? what repair?) Do not assume an operational definition is valid, just because a researcher has generated a number with it.
Examples of Operational Definitions
The best way to illustrate the process of developing operational definitions for variables is to identify several theoretical constructs and develop multiple operational definitions of each. This not only illustrates how the process is done, but also shows that most constructs can be measured in more than one way. The research literature also shows that it is common for different operational definitions to tap different aspects of a construct and thus react differently to experimental manipulations.
Anxiety
Anxiety is a concept that most of us are all too familiar with. It is an unpleasant feeling that occurs in certain situations. It can disrupt our functioning if it is excessive, but it also motivates behavior.
So how do you measure anxiety? How do you operationally define anxiety? Now this is a problem that has challenged researchers for years, and many fine operational definitions of anxiety are already available for our use. For the sake of this exercise, however, we will assume that we have to develop our own measure without benefit of much of this existing research.
Since this is a concept that we have first-hand knowledge of, we might start the process of operationally defining anxiety by asking ourselves what it is like. What do we feel? How do we react? How do others react? What features in other people would suggest to us that they are anxious? These are all excellent ways to start this process. It is especially useful to focus on factors that indicate anxiety in others, because those are likely to be more objective and observable factors and would provide higher reliability.
When we think of anxiety, we think first about the "feeling" of being anxious. We know what it is like and we can easily tell when we are experiencing it. It is less clear whether others would be able to tell that we are anxious just by looking at us. If fact, our own experience suggests that we may be effectively hiding our anxiety, because some people have told us they were impressed with how calm we were at a time when we felt anything but calm. Furthermore, others have told us they were very anxious in a situation in which we had observed them and they did not look anxious to us. Nevertheless, the feeling of anxiety is distinctive, even if it is not always public, so it provides one way of measuring anxiety.
Since feelings are internal events, apparently without consistent external features, we will have to rely on self-reports to find out whether a person is feeling anxious. We could simply ask people to rate their level of anxiety on a 100-point scale, a technique that is commonly used. These are often referred to as SUDS (subjective units of distress) ratings. We could instead ask people a number of questions about their feelings, questions that tap elements of anxious feelings. These might include things like "I am worried about what might happen." or "I can feel my heart pound." The number of such items endorsed by the person would likely indicate the level of anxiety. With mild anxiety, a few might be endorsed, but as the anxiety became more intense, more and more of the items would be endorsed, because more of the anxiety symptoms would be intense enough that the person noticed them.
We just mentioned something that probably resonated with many of you. When you are anxious, your heart feels as if it is pounding, and when you are very anxious, you almost always experience this sensation. This is a real effect. Anxiety is not just a feeling; it is also a physiological response. When we are anxious, our heart beats faster and stronger, our muscles tense and we shake, our palms sweat and sometimes even our face sweats, our voice may crack or our face flush. Sometimes these effects are visible to others; often they are not unless the anxiety is very strong.
We all have witnessed someone giving a talk in class who was visibly shaking, whose voice was cracking, and whose face lit up the entire room with a red glow. We can use these responses to provide another set of ways of operationally defining anxiety. We can measure the physiological changes in people as an indication of their anxiety. If their heart rate increases, we would take that as a sign of anxiety. If their palm sweats, that is another sign of anxiety. Without going into the complexities of how one measures each of these things, we will just say that it is relatively easy to do so, and that these measures have often been used to index the anxiety level of participants in studies. With modern telemetry, it is even possible to monitor many of these physiological responses while the person is carrying out everyday activities in his or her natural environment.
Most of the people who were obviously nervous about giving a talk in school somehow got through the talks, but a few quit in the middle, sometimes even leaving the room. This is yet another indicator of anxiety--in this case, the behavior of fleeing the situation. We do not see it often in classroom situations, but people who are anxious of snakes will often run away or at least step back from the object of their fear. Furthermore, we often see avoidance of situations that produce anxiety. Someone who has been very anxious giving talks in public may chose to only take classes that do not require a presentation. He or she may even chose jobs later that are unlikely to require a presentation, even though it may mean making considerably less or having a less prestigious job. So behavior, both escape and avoidance, is yet another indicator of anxiety.
We have outlined three separate strategies for operationally defining anxiety. They include (1) asking people how anxious they are feeling, (2) measuring their physiological response, and (3) observing their behavior, especially their escape and avoidance behaviour. The natural question for most students is which of these the BEST measure of anxiety is. In essence, which of the measures captures true anxiety most precisely?
The answer to this question for anxiety is often frustrating to students, but reflects the complex reality of human emotions. The answer is "It depends." Most students seem to prefer the physiological measures, because they seem more "basic." Certainly, the physiological measures have the advantage that we cannot deliberately lie about them. If we are anxious and we don't want people to know that we are anxious, we can always lie about how we feel, provided our anxiety is not so obvious that everyone can see signs of it. We can also stay in situations in spite of intense anxiety to avoid losing face or to do something that we feel is critical. Many nervous parents have spoken up at PTO meetings, because they thought it was important to the well being of their children.
But physiological measures also have their problems. The heart rate will indeed go up when we are anxious, but it also goes up for lots of other reasons as well. Walk up a flight of stairs and your heart rate will have increased several beats a minute to meet the aerobic demand. Your palms will sweat from nervousness, but they also sweat, along with the rest of your body, when you are hot. The same is true of face flushing. Your muscles will tighten when nervous, but they also tighten when you are expecting to act or are engaged in physical action. So none of our measures of anxiety is ideal.
If none of our measures of anxiety is ideal, which one should we use. The best answer is "as many as we can." The truth is that each of these measures capture a different aspect of the construct of anxiety, and therefore they do not always agree with one another. For example, people can avoid a situation without showing visible signs of anxiety, but the avoidance is a strong indicator of their feeling about the situation. Even though there may be little physiological arousal and they may claim to not be anxious, their avoidance is telling another story. The validity of that other story can often be confirmed if the person is required to face what they have been avoiding.
Looking at it from another perspective, we often see people with considerable anxiety, as measured by their physiological responses, performing all of the things required of them. Golfers might calmly sink a 10-foot putt to win a tournament, even though their heart might be racing and their palms are dripping wet. So are they anxious or not? Scientifically, the fact that these various measures of anxiety do not always agree has led to a much more thorough understanding of anxiety. We now know that it is not a single construct, but rather represents a complex collection of responses, and that the pattern that we will see will depend on the situation that the person is in. We would never have been able to recognize that if we had not operationally defined anxiety in several different ways and used all of those various definitions in our research studies
Conclusion
The Perfect Operational Definition
One must accept that there is no perfect operational definition for a given construct. Each operational definition will have advantages and disadvantages. A self-report measure is often quick and easy, but it is subject to presentational biases by the participants who take it. Actual counts of behavior are less affected by presentational biases, but they are much more time consuming and often miss critical behavior that is private. Physiological measures can tap some constructs, but physiological changes occur for many different reasons; therefore, it is hard to know if observed physiological changes are an indication of the construct of interested. Laboratory analogues have the advantage of experimental control, but there is always the question of how closely they relate to real world behavior.
Because no single operational definition is likely to provide the perfect measure of the construct of interested, it is wise to consider using more than one operational definition in a given research study. If you randomly select a dozen research studies from the best journals, you may be surprised to see how often this approach is used. Multiple operational definitions help us to zero in on the constructs that we are studying, and they often give us insights into the complexity of those constructs. We already discussed how anxiety researchers now recognize that the feelings, behavior, and physiology of anxiety are not just alternate ways of tapping anxiety, but represent distinctly different aspects of anxiety. By recognizing this basic fact, we can begin to identify how these various aspects of anxiety fit together. This is science at its best--a concerted effort at zeroing in on the workings of nature.
References
Creswell, J. W. (2008). Educational Research (3rd ed.). Upper Saddle River: Pearson Education, Inc.
Kerlinger, F. N. (1979). Behavioral research: A conceptual approach. New York: Holt, Rinehart, & Winston
Gay, L.R. (2009). Educational Research: competencies for analysis and application/L.R. Gay, Geoffrey E. Mills, Peter W. Airasin.-9th ed.
Jhon W. Best and James V. Khan (2009). Research in Education, 10th Ed
http://www.psywww.com/intropsych/ch01_psychology_and_science/variables_and_values.html
http://www.mikeraulin.org/graziano7e/default.htm
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