SA-08(01) Clear Abstractions

Baselines

Guidance

The principle of clear abstractions states that a system has simple, well-defined interfaces and functions that provide a consistent and intuitive view of the data and how the data is managed. The clarity, simplicity, necessity, and sufficiency of the system interfaces— combined with a precise definition of their functional behavior—promotes ease of analysis, inspection, and testing as well as the correct and secure use of the system. The clarity of an abstraction is subjective. Examples that reflect the application of this principle include avoidance of redundant, unused interfaces; information hiding; and avoidance of semantic overloading of interfaces or their parameters. Information hiding (i.e., representation-independent programming), is a design discipline used to ensure that the internal representation of information in one system component is not visible to another system component invoking or calling the first component, such that the published abstraction is not influenced by how the data may be managed internally.