Barbara Liskov (born November 7, 1939 as Barbara Jane Huberman) is an American

computer scientist A computer scientist is a person who is trained in the academic study of computer science. Computer scientists typically work on the theoretical side of computation, as opposed to the hardware side on which computer engineers mainly focus (a ...

who has made pioneering contributions to

programming languages A programming language is a system of notation for writing computer programs. Most programming languages are text-based formal languages, but they may also be graphical. They are a kind of computer language. The description of a programming ...

and

distributed computing A distributed system is a system whose components are located on different networked computers, which communicate and coordinate their actions by passing messages to one another from any system. Distributed computing is a field of computer sci ...

. Her notable work includes the development of the

Liskov substitution principle The Liskov substitution principle (LSP) is a particular definition of a subtyping relation, called strong behavioral subtyping, that was initially introduced by Barbara Liskov in a 1988 conference keynote address titled ''Data abstraction and ...

which describes the fundamental nature of

data abstraction In software engineering and computer science, abstraction is: * The process of removing or generalizing physical, spatial, or temporal details or attributes in the study of objects or systems to focus attention on details of greater importance ...

, and is used in

type theory In mathematics, logic, and computer science, a type theory is the formal presentation of a specific type system, and in general type theory is the academic study of type systems. Some type theories serve as alternatives to set theory as a founda ...

(see subtyping) and in

object-oriented programming Object-oriented programming (OOP) is a programming paradigm based on the concept of "objects", which can contain data and code. The data is in the form of fields (often known as attributes or ''properties''), and the code is in the form of ...

(see

inheritance Inheritance is the practice of receiving private property, titles, debts, entitlements, privileges, rights, and obligations upon the death of an individual. The rules of inheritance differ among societies and have changed over time. Of ...

). Her work was recognized with the 2008

Turing Award The ACM A. M. Turing Award is an annual prize given by the Association for Computing Machinery (ACM) for contributions of lasting and major technical importance to computer science. It is generally recognized as the highest distinction in compu ...

, the highest distinction in computer science. Liskov is one of the earliest women to have been granted a doctorate in computer science in the United States, and the second woman to receive the Turing award. She is currently an Institute Professor and Ford Professor of Engineering at the

Massachusetts Institute of Technology The Massachusetts Institute of Technology (MIT) is a private land-grant research university in Cambridge, Massachusetts. Established in 1861, MIT has played a key role in the development of modern technology and science, and is one of th ...

.Barbara Liskov
Programming Methodology Group, MIT.

Early life and education

Liskov was born November 7, 1939, in Los Angeles, California, to a Jewish family, the eldest of Jane (née Dickhoff) and Moses Huberman's four children. She earned her bachelor's degree in mathematics with a minor in physics at the

University of California, Berkeley The University of California, Berkeley (UC Berkeley, Berkeley, Cal, or California) is a public land-grant research university in Berkeley, California. Established in 1868 as the University of California, it is the state's first land-grant un ...

in 1961. She had only one other female classmate. After she graduated she applied to graduate mathematics programs at Berkeley and

Princeton Princeton University is a private research university in Princeton, New Jersey. Founded in 1746 in Elizabeth as the College of New Jersey, Princeton is the fourth-oldest institution of higher education in the United States and one of the nin ...

. At the time Princeton was not accepting female students in mathematics. She was accepted at Berkeley but instead of studying she moved to Boston and began working at Mitre Corporation. It was there that she became interested in computers and programming. She worked at Mitre for one year before taking a programming job at Harvard where she worked on language translation. She then decided to go back to school and applied again to Berkeley, but also to Stanford and Harvard. In 1968 she became one of the first women in the United States to be awarded a Ph.D. from a computer science department when she was awarded her degree from

Stanford University Stanford University, officially Leland Stanford Junior University, is a private research university in Stanford, California. The campus occupies , among the largest in the United States, and enrolls over 17,000 students. Stanford is conside ...

. At Stanford, she worked with John McCarthy and was supported to work in

artificial intelligence Artificial intelligence (AI) is intelligence—perceiving, synthesizing, and inferring information—demonstrated by machines, as opposed to intelligence displayed by animals and humans. Example tasks in which this is done include speech ...

. The topic of her Ph.D. thesis was a computer program to play chess endgames for which she developed the important

killer heuristic In competitive two-player games, the killer heuristic is a move-ordering method based on the observation that a strong move or small set of such moves in a particular position may be equally strong in similar positions at the same move (ply) in t ...

Career

After graduating from Stanford, Liskov returned to Mitre to work as research staff. Liskov has led many significant projects, including the Venus operating system, a small, low-cost

timesharing In computing, time-sharing is the sharing of a computing resource among many users at the same time by means of multiprogramming and multi-tasking.DEC Timesharing (1965), by Peter Clark, The DEC Professional, Volume 1, Number 1 Its emergence ...

system; the design and implementation of CLU; Argus, the first high-level language to support implementation of distributed programs and to demonstrate the technique of promise pipelining; and Thor, an object-oriented database system. With Jeannette Wing, she developed a particular definition of subtyping, commonly known as the

. She leads the Programming Methodology Group at MIT, with a current research focus in

Byzantine fault tolerance A Byzantine fault (also Byzantine generals problem, interactive consistency, source congruency, error avalanche, Byzantine agreement problem, and Byzantine failure) is a condition of a computer system, particularly distributed computing systems, ...

and

. She was on the inaugural Engineering and Computer Science jury for the

Infosys Prize The Infosys Prize is an annual award given to scientists, researchers, engineers and social scientists of Indian origin (not necessarily born in India) by the Infosys Science Foundation and ranks among the highest monetary awards in India to r ...

in 2009.

Recognition and awards

Liskov is a member of the

National Academy of Engineering The National Academy of Engineering (NAE) is an American nonprofit, non-governmental organization. The National Academy of Engineering is part of the National Academies of Sciences, Engineering, and Medicine, along with the National Academy of ...

, the

National Academy of Sciences The National Academy of Sciences (NAS) is a United States nonprofit, non-governmental organization. NAS is part of the National Academies of Sciences, Engineering, and Medicine, along with the National Academy of Engineering (NAE) and the Nat ...

and a fellow of the

American Academy of Arts and Sciences The American Academy of Arts and Sciences (abbreviation: AAA&S) is one of the oldest learned societies in the United States. It was founded in 1780 during the American Revolution by John Adams, John Hancock, James Bowdoin, Andrew Oliver, a ...

and of the

Association for Computing Machinery The Association for Computing Machinery (ACM) is a US-based international learned society for computing. It was founded in 1947 and is the world's largest scientific and educational computing society. The ACM is a non-profit professional member ...

(ACM). In 2002, she was recognized as one of the top women faculty members at MIT, and among the top 50 faculty members in the sciences in the U.S. In 2002, ''

Discover Discover may refer to: Art, entertainment, and media * ''Discover'' (album), a Cactus Jack album * ''Discover'' (magazine), an American science magazine Businesses and brands * DISCover, the ''Digital Interactive Systems Corporation'' * D ...

'' magazine recognized Liskov as one of the 50 most important women in science. In 2004, Barbara Liskov won the John von Neumann Medal for "fundamental contributions to programming languages, programming methodology, and distributed systems". On 19 November 2005, Barbara Liskov and Donald E. Knuth were awarded ETH Honorary Doctorates. Liskov and Knuth were also featured in the ETH Zurich Distinguished Colloquium Series. She was awarded a Doctorate Honoris Causa by the

University of Lugano A university () is an institution of higher (or tertiary) education and research which awards academic degrees in several academic disciplines. Universities typically offer both undergraduate and postgraduate programs. In the United States, ...

in 2011 and by

Universidad Politécnica de Madrid The Technical University of Madrid or sometimes called Polytechnic University of Madrid ( es, Universidad Politécnica de Madrid, UPM) is a public university, located in Madrid, Spain. It was founded in 1971 as the result of merging different Te ...

in 2018. Liskov received the 2008

from the ACM in March 2009, for her work in the design of programming languages and software methodology that led to the development of

.Barbara Liskov Wins Turing Award , March 10, 2009
from the Dr. Dobb's Journal website Specifically, Liskov developed two programming languages, CLU in the 1970s and Argus in the 1980s. The ACM cited her contributions to the practical and theoretical foundations of "programming language and

system design Systems design interfaces, and data for an electronic control system to satisfy specified requirements. System design could be seen as the application of system theory to product development. There is some overlap with the disciplines of system ana ...

, especially related to

, fault tolerance, and

". In 2012 she was inducted into the

National Inventors Hall of Fame The National Inventors Hall of Fame (NIHF) is an American not-for-profit organization, founded in 1973, which recognizes individual engineers and inventors who hold a U.S. patent of significant technology. Besides the Hall of Fame, it also oper ...

Selected works

Liskov is the author of four books and over one hundred technical papers.

Books

* * * *

Selected papers

* * * * * *

Personal life

In 1970, she married Nathan Liskov. They have one son, Moses, who earned a PhD in computer science from MIT in 2004 and teaches computer science at the

College of William and Mary The College of William & Mary (officially The College of William and Mary in Virginia, abbreviated as William & Mary, W&M) is a public research university in Williamsburg, Virginia. Founded in 1693 by letters patent issued by King William ...

References

External links

Prof. Liskov's home page

Programming Methodology Group

Interview in Quanta magazine
*

Tom Van Vleck Tom Van Vleck is an American computer software engineer. Life and work Van Vleck graduated from MIT in 1965 with a BS in Mathematics. He worked on CTSS at MIT, and co-authored its first email program with Noel Morris. In 1965, he joined Proje ...

Barbara Liskov
A.M. Turing Award Winner
National Public Radio "Science Friday" interview with Barbara Liskov, originally aired on 13 Mar 2009
*
Celebrating Women of Distinction, Barbara Liskov, Turing Award interview by

Stephen Ibaraki Stephen K. Ibaraki has been a teacher, an industry analyst, writer and consultant in the IT industry, and the former president of the Canadian Information Processing Society. Currently, Ibaraki is a venture capitalist, entrepreneur, futurist and ...

* Prof. Liskov summarizes her career and offers advice to young women engineers
--> * John V. Guttag
Barbara Liskov
''The Electron and The Bit: EECS at MIT, 1902–2002'', Chapter VII: "Pioneering Women in EECS", pp. 225–239, 2003, Department of Electrical Engineering and Computer Science, MIT
Barbara Liskov named Institute Professor
MIT News, July 1, 2008
Department News: Barbara Liskov named Institute Professor
, EECS Newsletter, Fall 2008 * Natasha Plotkin

''The Tech'' (MIT), 128,29, July 9, 2008 * Robert Weisman
Top prize in computing goes to MIT professor
''

The Boston Globe ''The Boston Globe'' is an American daily newspaper founded and based in Boston, Massachusetts. The newspaper has won a total of 27 Pulitzer Prizes, and has a total circulation of close to 300,000 print and digital subscribers. ''The Boston Glob ...

'', March 10, 2009 * Erica Naone
Driven to Abstraction
''MIT Technology Review'', December 21, 2009
Barbara Liskov
at the Chess programming wiki {{DEFAULTSORT:Liskov, Barbara University of California, Berkeley alumni Programming language designers American women computer scientists American computer scientists 1939 births Living people American women academics Programming language researchers Researchers in distributed computing Fellows of the Association for Computing Machinery Members of the United States National Academy of Engineering Members of the United States National Academy of Sciences Turing Award laureates MIT School of Engineering faculty Stanford University School of Engineering alumni Jewish American scientists Jewish women scientists 20th-century American engineers 21st-century American engineers 20th-century American women scientists 21st-century American women scientists Women inventors