Portrait of Maurice H. Halstead

Maurice H. Halstead

Maurice H. ("Maury") Halstead was at the frontier of software metrics and software engineering. One of the first faculty in Purdue's Department of Computer Science, he introduced an approach to defining and measuring software products and processes, which became the foundation of modern software science.

In Halstead's conception, computer programs were to be treated "as neither art forms nor as examples of mathematical logic, but instead as basic material which can be investigated with the classical methods of experimental and theoretical natural science," said Raymond T. Yeh, editor of IEEE Transactions on Software Engineering, upon Professor Halstead's death in 1979. Halstead's goal was to identify measurable properties of software and the relations between them, similar to the identification of measurable properties of matter (like the volume, mass, and pressure of a gas) and the relationships between them. In his 1977 book, "Elements of Software Science," a classic work in the field, he introduced the concept of complexity measures, which are metrics that assess a program's complexity and are computed statically from the source code, independent of execution on a particular platform.

Professor Halstead was a fellow in physics of the American Association for the Advancement of Science and served on the Association for Computing Machinery's SIGPLAN executive committee. An annual award in his name is given by the Purdue Department of Computer Science to a graduate student who has made significant contributions to software engineering.

Professor Halstead actually began his career in atmospheric science, and had early success with cloud seeding in Hawaii. After earning a bachelor's degree in physics and meteorology from the University of California-Berkeley in 1940, and a master's degree in aerological engineering from the U.S. Naval Academy Postgraduate School in 1943, he enrolled at Johns Hopkins University to pursue a doctorate in physical science, which he received in 1951. He first became interested in computer design after becoming an assistant director of the Laboratory of Climatology while at Johns Hopkins. In 1957, Professor Halstead established the computational center at the Navy Electronics Laboratory in San Diego, where he worked on NELIAC, one of the first implementations of a high-level programming language translator, and wrote one of the first books on compiler implementation. He then worked at Lockheed Missiles and Space before joining the Purdue faculty in 1968.