Definitions

After this lesson, the reader should understand:

• 01Explain why definition drift changes outcomes without changing rules.
• 02Scope a definition to an instrument, a domain, or a jurisdiction.
• 03Detect a term used with two meanings in one instrument.

Who counts as an employee

One organisation, three definitions of 'employee'. What breaks?

Payroll, benefits eligibility, and security clearance each inherited a different definition from a different instrument. Every rule downstream is individually correct and collectively inconsistent. Expressed as artifacts, the divergence is visible before deployment because the definitions are named objects rather than repeated phrases — and the institution must decide, once, which one governs where.

• Should definitions be shared across instruments or duplicated deliberately?
• What happens to decisions made under a superseded definition?
• Can a definition be delegated to an external register?

Build a definition register for one instrument.

1. 01List every defined and quasi-defined term.
2. 02Record criteria and exclusions for each.
3. 03Mark terms that appear with more than one meaning.
4. 04Propose the governing definition for each conflict.

• Terminology science and controlled vocabularies.
• Ontology engineering — identity and subsumption.
• Statutory interpretation — defined terms and context.