An operational definition is a definition of some term or [[Constructs|construct]]. When researchers are constructing their theories or journalists are describing their research, they usually refer to the constructs, for example satisfaction with life. However, when researchers are collecting empirical evidence and undergoing a study they must use a operational definition. For example with the previous construct the operational definition might be: Five questionnaire items on the Satisfaction with Life scale, answered on a scale of 1 (_strongly disagree) to 5 (_strongly agree). An example item is “All in all, I am satisfied with my life.