"On the Cruelty of Really Teaching Computing Science" is a 1988

scholarly article Academic publishing is the subfield of publishing which distributes academic research and scholarship. Most academic work is published in academic journal articles, books or theses. The part of academic written output that is not formally publis ...

by E. W. Dijkstra which argues that

computer programming Computer programming or coding is the composition of sequences of instructions, called computer program, programs, that computers can follow to perform tasks. It involves designing and implementing algorithms, step-by-step specifications of proc ...

should be understood as a branch of

mathematics Mathematics is a field of study that discovers and organizes methods, Mathematical theory, theories and theorems that are developed and Mathematical proof, proved for the needs of empirical sciences and mathematics itself. There are many ar ...

, and that the formal provability of a

program Program (American English; also Commonwealth English in terms of computer programming and related activities) or programme (Commonwealth English in all other meanings), programmer, or programming may refer to: Business and management * Program m ...

is a major criterion for correctness. Despite the title, most of the article is on Dijkstra’s attempt to put

computer science Computer science is the study of computation, information, and automation. Computer science spans Theoretical computer science, theoretical disciplines (such as algorithms, theory of computation, and information theory) to Applied science, ...

into a wider perspective within

science Science is a systematic discipline that builds and organises knowledge in the form of testable hypotheses and predictions about the universe. Modern science is typically divided into twoor threemajor branches: the natural sciences, which stu ...

, teaching being addressed as a

corollary In mathematics and logic, a corollary ( , ) is a theorem of less importance which can be readily deduced from a previous, more notable statement. A corollary could, for instance, be a proposition which is incidentally proved while proving another ...

at the end. Specifically, Dijkstra made a “proposal for an introductory programming course for freshmen” that consisted of

Hoare logic Hoare logic (also known as Floyd–Hoare logic or Hoare rules) is a formal system with a set of logical rules for reasoning rigorously about the correctness of computer programs. It was proposed in 1969 by the British computer scientist and l ...

as an uninterpreted

formal system A formal system is an abstract structure and formalization of an axiomatic system used for deducing, using rules of inference, theorems from axioms. In 1921, David Hilbert proposed to use formal systems as the foundation of knowledge in ma ...

Debate over feasibility

Since the term "software engineering" was coined,

formal verification In the context of hardware and software systems, formal verification is the act of proving or disproving the correctness of a system with respect to a certain formal specification or property, using formal methods of mathematics. Formal ver ...

has almost always been considered too resource-intensive to be feasible. In complex applications, the difficulty of correctly specifying what the program should do in the first place is also a common source of error. Other methods of

software testing Software testing is the act of checking whether software satisfies expectations. Software testing can provide objective, independent information about the Quality (business), quality of software and the risk of its failure to a User (computin ...

are generally employed to try to eliminate bugs and many other factors are considered in the measurement of

software quality In the context of software engineering, software quality refers to two related but distinct notions: * Software's functional quality reflects how well it complies with or conforms to a given design, based on functional requirements or specificat ...

. Until the end of his life, Dijkstra maintained that the central challenges of computing hadn't been met to his satisfaction, due to an insufficient emphasis on

program correctness In theoretical computer science, an algorithm is correct with respect to a specification if it behaves as specified. Best explored is ''functional'' correctness, which refers to the input–output behavior of the algorithm: for each input it produ ...

(though not obviating other requirements, such as

maintainability Maintainability is the ease of maintaining or providing maintenance for a functioning product or service. Depending on the field, it can have slightly different meanings. Usage in different fields Engineering In engineering, maintainability ...

and

efficiency Efficiency is the often measurable ability to avoid making mistakes or wasting materials, energy, efforts, money, and time while performing a task. In a more general sense, it is the ability to do things well, successfully, and without waste. ...

Pedagogical legacy

Computer science as taught today does not follow of Dijkstra's advice. The curricula generally emphasize techniques for managing complexity and preparing for future changes, following Dijkstra's earlier writings. These include

abstraction Abstraction is a process where general rules and concepts are derived from the use and classifying of specific examples, literal (reality, real or Abstract and concrete, concrete) signifiers, first principles, or other methods. "An abstraction" ...

programming by contract Design by contract (DbC), also known as contract programming, programming by contract and design-by-contract programming, is an approach for designing software. It prescribes that software designers should define formal, precise and verifiable i ...

, and

design patterns ''Design Patterns: Elements of Reusable Object-Oriented Software'' (1994) is a software engineering book describing software design patterns. The book was written by Erich Gamma, Richard Helm, Ralph Johnson, and John Vlissides, with a fore ...

. Programming techniques to avoid bugs and conventional software testing methods are taught as basic requirements, and students are exposed to certain mathematical tools, but formal verification methods are not included in the curriculum except perhaps as an advanced topic. So in some ways, Dijkstra's ideas have been adhered to; however, the ideas he felt most strongly about have not been. Newly formed curricula in software engineering have adopted Dijkstra's recommendations. The focus of these programs is the formal specification of software requirements and design in order to facilitate the formal validation of system correctness. In Canada, they are often accredited engineering degrees with similar core competencies in physics-based engineering.

References

{{Edsger Dijkstra 1988 documents Computer science papers Computer science education Works by Edsger W. Dijkstra