Aspects of abstraction in software development

- Abstraction is a fundamental tool of human thought in every context. This essay briefly reviews some manifestations of abstraction in everyday life, in engineering and mathematics, and in software and system development. Vertical and horizontal abstraction are distinguished and characterised. The use of vertical abstraction in top-down and bottom-up program development is discussed, and also, the use of horizontal abstraction in one very different approach to program design. The ubiquitous use of analogical models in software is explained in terms of analytical abstractions. Some aspects of the practical use of abstraction in the development of computer-based systems are explored. The necessity of multiple abstractions is argued from the essential nature of abstraction, which by definition focuses on some concerns at the expense of discarding others. Finally, some general recommendations are offered for a consciously thoughtful use of abstraction in software development.