Question

What is the difference between the conceptual variable and the operational definition of a variable? How might the conceptual variables “affection,” “intelligence”, and “stress” be operationalized by a researcher?

Answer 1

• A conceptual definition tells you what the concept means, while an operational definition only tells you how to measure it. A conceptual definition tells what your constructs are by elplaining how they are related to other constructs. This explanation and all of the constructs it refers to are abstract.
• Conceptual variables are often expressed in general, theoretical, qualitative, or subjective terms and important in hypothesis building process.
• Two levels of abstraction exist for our research activities and our understanding of research outcomes. Everyone understands at conceptual level.
• For example, if you say "Computer games sharpen children's minds" expresses a belief about a causal relationship at a conceptual level. At this level of abstraction, the variables are called constructs or conceptual variables.
• Conceptual variables are often expressed in general, theoretical, subjective, or qualitative terms. The research hypothesis is usually starts at this level, for example. "Effect of nicotine patch is poorer among people lacking mental determination to quit smoking".
• To measure conceptual variables, an objective definition is often required. This may involve having an easily available validated instrument, inferring an operational variable from theory, establishing consensus or all three. In above example, we need to have a definition of effect of nicotine patch and mental determination.
• The operational definition of a variable is the specific way in which it is measured in that study. Another study might measure the same conceptual measure differently. If you were studying ways of helping people stop smoking, smoking cessation would be an outcome measure (dependent variable).
• You could measure smoking cessation as a person not smoking a cigarette for 1 month, or as a person who has not smoked in a year, or a 50% reduction in the number of cigarettes smoked.
• Clearly the operational definition of the dependent variable is an important step in the design of the study. Some other health related conceptual variables that have many operational definitions: intelligence, fitness, health, quality of life.
  
• Thus, an operational definition might define intelligence as whatever it is that intelligence tests measure.
• A rough conceptual definition is that stress is an adaptive response to a perceived danger or threat that involves physiological, cognitive, affective, and behavioral components. But researchers have operationally defined it in several ways.
• The Social Readjustment Rating Scale is a self-report questionnaire on which people identify stressful events that they have experienced in the past year and assigns points for each one depending on its severity.
• Researchers have also operationally defined stress in terms of several physiological variables including blood pressure and levels of the stress hormone cortisol.