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 procedures included in definitions should be repeatable by anyone or at least by peers. An example of operational definition of the term weight of an object, operationalized to a degree, would be the following: weight is the numbers that appear when that object is placed on a weighing scale .he procedures included in definitions should be repeatable by anyone or at least by peers. An example of operational definition of the term weight of an object, operationalized to a degree, would be the following: weight is the numbers that appear when that object is placed on a weighing scale .