Operational Definition

Posted on November 2, 2009 by


An operational definition is how a construct will be measured. This includes measurements in research studies such as Six Sigma studies. For example, in a pet obesity study a new weight loss drug will be given to overweight cats. But what is an overweight cat? Someone may suggest that if the cat is 15 pounds or larger, it is overweight. This is an operational definition, but it is not a great one because some cat breeds such as a good-sized Maine Coon could be thin at that weight. Another cat study needs a sample of happy cats. This is harder! Perhaps cats who purr ten minutes or greater on average per day with a complete absence of hissing and growling could be considered happy cats. As can be seen, if an operational definition is poor, the entire study can be poor. It is important not to rush the step of developing good operational definitions when conducting a study.