The cause of an acute exacerbation is usually unknown, although some acute exacerbations result from bacterial or viral infections. Smoking, irritative inhalational exposure, and high levels of air pollution also contribute.
Operational Definition. 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).ou 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.
The following table shows examples of variables, operational definitions, and values. 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. You could argue that the last definition is an operational definition.istinguishing 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.