Operational definitions are statements of the procedures used to define the research variables in a study. having these helps other researchers "replicate" the study.
An operational definition, when applied to information gathering, is an unmistakable, succinct point by point meaning of a measure. The requirement for operational definitions is central when gathering a wide range of information. It is especially critical when a choice is being made about in the case of something is right or off base, or when a visual check is being made where there is space for confusion.