Operational Definition

Operational Definition image
An operational definition explains what a concept means in practical, measurable terms. It makes abstract or vague ideas concrete so that people are more likely to understand them in the same way and test them consistently. 

W. Edwards Deming wrote that "an operational definition puts communicable meaning into a concept. Adjectives like good, reliable, uniform, round, tired, safe, unsafe, unemployed have ot communicable meaning until they are expressed in operational terms of sampling, test and criterion." Out of the Crisis, (1986, chapter 9) 

Deming gave this example of an operational definition:
  1. “A specification test of a piece of metal or an assembly
  2. A criterion (or criteria) for judgement
  3. Decision: yes or no, the object or the material did or did not meet the criterion (or criteria)”

Another example of operational definition would be:
  • A specification, for example:
    • As a Gmail user
    • I want to log in to my Gmail account
    • So that I can check my email
  • Criteria, for example:
    • Acceptance criteria
    • I can see emails sent to my Gmail address
  • A decision as to whether what is being tested meets the criteria, for example:
    • The definition of "done" includes that all acceptance criteria will be tested
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