Barbara Liskov

Barbara Liskov
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Name	Barbara Liskov
Caption	Liskov at MIT in 2010
Birth name	Barbara Jane Huberman
Birth date	7 November 1939
Birth place	Los Angeles, California, U.S.
Fields	Computer science
Workplaces	MIT
Alma mater	University of California, Berkeley (BA), Stanford University (MS, PhD)
Doctoral advisor	John McCarthy
Known for	Liskov substitution principle, CLU, Argus, Thor
Awards	John von Neumann Medal (2004), Turing Award (2008), National Medal of Technology and Innovation (2012)

Barbara Liskov is an American computer scientist and Institute Professor at the Massachusetts Institute of Technology. A pioneer in programming language design and distributed computing, she is renowned for fundamental contributions to data abstraction, object-oriented programming, and software engineering. Her work has profoundly influenced the design of modern programming languages and the development of reliable, scalable software systems.

Early life and education

Born in Los Angeles, she earned a Bachelor of Arts in mathematics from the University of California, Berkeley in 1961. Initially interested in mathematics, she shifted her focus to the emerging field of computer science. She subsequently moved to Palo Alto and became one of the first women in the United States to earn a Doctor of Philosophy in computer science, completing her doctorate at Stanford University in 1968 under the supervision of John McCarthy. Her doctoral dissertation, titled "A Program to Play Chess Endgames," was a significant early work in artificial intelligence.

Career and research

After completing her PhD, she worked at the Mitre Corporation before joining the faculty of the Massachusetts Institute of Technology in 1972, where she has remained for her entire career. At MIT, she led the design and implementation of the CLU programming language in the 1970s, which pioneered key concepts of data abstraction and abstract data types that are foundational to modern object-oriented programming. This work was followed by the development of the Argus language, which introduced linguistic support for distributed programs and the implementation of atomic transactions, influencing later systems like the Java Remote Method Invocation. Her research group also created the Thor object-oriented database system, exploring persistent, recoverable data storage.

Liskov substitution principle

In a seminal 1987 conference paper with Jeannette Wing, she formulated what became known as the Liskov substitution principle, a fundamental definition of subtype in type theory and object-oriented programming. The principle states that if a program module is using a base class, then it should be able to use any of its derived classes without the program's correctness being affected. This concept is a cornerstone of the design by contract methodology and is integral to the design of major programming languages like C++, Java, and C#. It rigorously defines the behavioral relationship necessary for true inheritance, ensuring robust and maintainable software architecture.

Awards and honors

Her contributions have been recognized with the highest honors in computer science. She received the John von Neumann Medal from the Institute of Electrical and Electronics Engineers in 2004. In 2008, she was awarded the ACM Turing Award, often described as the "Nobel Prize of Computing," for her foundational contributions to practical and theoretical foundations of programming language and system design. She was a co-recipient of the SIGPLAN Programming Languages Achievement Award in 2008. In 2012, she was awarded the National Medal of Technology and Innovation by President Barack Obama. She is a member of the National Academy of Engineering, the National Academy of Sciences, and the American Academy of Arts and Sciences, and is a fellow of the Association for Computing Machinery and the American Association for the Advancement of Science.

Selected publications

Key publications include the 1977 paper "Abstraction Mechanisms in CLU" in the Communications of the ACM, the 1987 paper "Family Values: A Behavioral Notion of Subtyping" (with Jeannette Wing), and the 1999 book "Program Development in Java: Abstraction, Specification, and Object-Oriented Design" (with John Guttag). These works have become standard references in the study of programming language semantics, software specification, and object-oriented design.

Category:American computer scientists Category:Turing Award laureates Category:Massachusetts Institute of Technology faculty Category:Members of the United States National Academy of Sciences Category:Members of the United States National Academy of Engineering