BWhat changed
The article makes progressive task/data design, revisable choices, representation delay and reuse visible through one developed and extended nontrivial program.
Scientific scope
The article makes progressive task/data design, revisable choices, representation delay and reuse visible through one developed and extended nontrivial program. This is a worked design/teaching methodology, not a universal formal refinement theorem, first invention of backtracking or measured guarantee of software productivity. Original timings and solution counts are author-reported and unreplayed. Pascal, Hoare/Dijkstra correctness work and later refinement calculi retain separate credit.
Evidence
Source-linked, scoped account of the original work. The published scope states the scientific assumptions and remaining verification limits. WRS has not independently certified the full proof, experimental result or system benchmark.
Contributors
- Niklaus Wirth · SCIENCE: Original source-listed scientific author of this scoped work; byline does not determine effort fractions.
- Niklaus Wirth, Program Development by Stepwise Refinement, Communications of the ACM 14(4),221–227 (1971), DOI 10.1145/362575.362577
- ETH Zurich Research Collection: Program development by step-wise refinement (1971 report)
Provisional WRS assessment, edition 2026-10-16.1. Independent expert calibration is pending. This grade does not certify correctness or assign ownership.
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