What is an Operational Definition?
The OPERATIONAL DEFINITION makes the abstract qualities concrete. It describes the observable characteristics of a variable--the things that the researcher can observe or measure directly. The things you can see and measure are visible representations of the abstract qualities. The operational definition has 3 parts: it gives concrete definitions for abstract qualities, it names the values of the variable, and it assigns a number to each value of the variable.
The CONCEPTUAL DEFINITION provides an abstract, every-day, dictionary-like description.
For example, self-esteem is a measure of how people feel about themselves.
The OPERATIONAL DEFINITION provides a concrete description of the variable. If the variable is not directly measurable, it identifies aspects of the variable that can be
directly measured. In addition, whether or not the variable can be directly measured, the operational definition names the possible values of the variable.
For example, self-esteem is a measure of how people feel about themselves. It is not directly measurable. Three aspects of self-esteem that can be measured are: levels
of confidence in success, level of belief that the person is good enough, and willingness to ask questions. The values that levels of confidence might take on are: no confidence, low confidence, neither confident nor not confident, high confidence, very high confidence.
What's an operational definition? A concept that is defined operationally can be reduced to a set of rules to be preformed e.g. time is that quantity which comes in
units of seconds which can be measured by a stopwatch. Contrast this with Newton's time which "flow's equably without regard to any thing external...". (Although the scope of an operational definition is narrower, it is more concrete, allowing scientists to get on with description and explanation without getting bogged down in abstract
philosophical debates.)
A Quick Example of an Operational Definition
For example, the variable "course difficulty" might be operationally defined as:
an assessment of the grade level of the reading material, number of office hours the instructor holds, average grade on exams, etc. measured on a 5 point scale where 1=very low and 5=very high and a difficult course is one where the grade level of the reading materials is high and the number of office hours and average grade on exams are low.