Page Table of Content

Requirement

Title	Principles for definitions for concepts
Identifier	SWIM-INFO-010
Requirement	An information definition should apply the following principles for the definitions of its concepts when not using the definition from the AIRM: the definition should be concise, clear, and whenever possible no longer than one sentence; the definition should state what the concept is, rather than what it is not; the definition should not use words whose definitions refer back to the concept in question, or begin with the term itself; and the definition should not be a paraphrase of the term, but rather a description the concept.
Rationale	Interoperability is dependent on detailed definitions that are well understood, and understood in the same way by all participants. At a very minimum, the definitions should be of good quality. This requirement promotes good quality definitions.
Verification	Correctness
Examples/Notes	Example: “Aerodrome” is defined by ICAO as “A defined area on land or water (including any buildings, installations and equipment) intended to be used either wholly or in part for the arrival, departure and surface movement of aircraft.”
Level of Implementation	Recommended

Guidance

Examples of applying the principles

The example given in the specification itself shows how the principles are applied.

Other examples of where the principles have been applied are taken from the AIRM's list of ATM Business Terms:

Acrobatic flight: Manoeuvres intentionally performed by an aircraft involving an abrupt change in its attitude, an abnormal attitude, or an abnormal variation in speed.
Passenger aircraft: An aircraft that carries any person other than a crew member, an operator's employee in an official capacity, an authorized representative of an appropriate national authority or a person accompanying a consignment or other cargo.
Runway: A defined rectangular area on a land aerodrome prepared for the landing and take-off of aircraft.

Examples of not applying the principles

The principles have not been applied in the following examples. This has been created for the purpose of the example as is not taken from a particular standard.

Runway: A runway at an aerodrome.
Significant point: A point that is significant to ATM.

Further guidance

More information on defining concepts can be found in the ISO11179 Part 4 standard that is available at https://standards.iso.org/ittf/PubliclyAvailableStandards/c035346_ISO_IEC_11179-4_2004(E).zip

Verification Support

Correctness

Check that:

[ ] The information definition has applied the principles for definitions for each of its concepts.

SWIM-INFO-010 Principles for definitions for concepts