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.
An operational definition, when applied to data collection, is a clear, concise detailed definition of a measure. The need for operational definitions is fundamental when collecting all types of data. It is important that the operational definition is documented and standardized. 2  Definitions should be included in training materials and job procedure sheets. 3  The results of steps 1 through 4 should be included in one document. 4  The operational definition and the appropriate standards should be kept at the work station.