Ada Lovelace Day: Dr. Barbara Liskov, Computer Scientist
To call Dr. Liskov a breaker of barriers would be a bit of an understatement. She was the first US woman to be awarded a PhD in computer science (from Stanford, 1968) and the first woman to become a faculty member in computer science at MIT when she was hired there in 1972.1 Dr. Liskov has spent a long and productive career in research and administration at MIT, where she is currently serving as an Associate Provost for Faculty Equity,2 as well as Ford Professor of Engineering in the Department of Electrical Engineering and Computer Science, where she leads the Programming Methodology Group.3
In 2008, Dr. Liskov was named an Institute Professor at MIT, only the second woman to achieve the school's highest faculty rank,4 and earlier this month, she was awarded the 2008 A. M. Turing Award from the Association for Computing Machinery for "contributions to practical and theoretical foundations of programming language and system design, especially related to data abstraction, fault tolerance, and distributed computing,"5 also the second woman to do so. These are just a couple of her most recent honors, which also include an honorary doctorate from the Swiss Federal Institute of Technology in 2005 and the IEEE John von Neumann Medal in 2004.6
Throughout her career in computer science, Dr. Liskov's determination and curiosity have propelled her toward new insights into how computers can and should function. In 1971, a full four years before the release of the Altair, the switch-operated kit computer, Dr. Liskov created VENUS, an operating system whose elegant design could support multiple concurrent users and put into practice some early principles of data abstraction,7 developments that would prove to be essential to modern computing.
Dissatisfied with her own and others' work on the methodology of programming, however, and believing that code could be written more simply and more efficiently, Dr. Liskov went on to create the first object-oriented programming language, CLU, and its successor, Argus.8 Her current research concerns optimization of data management in distributed computing, centered around an object-oriented database called Thor.9
In 1987, Dr. Liskov (in conjunction with Jeannette Wing) developed the Liskov substitution principle,10 regarding consistency and fault tolerance in programming, stating that "functions that use pointers or references to base classes must be able to use objects of derived classes without knowing it."11 Deceptively simple and widely debated, this principle strikes at the heart of how to create a resilient, sustainably designed program.
During her education and early career, Dr. Liskov kept a low profile in order to survive as a woman in what was and still is a male-dominated field. When she completed her degree, Dr. Liskov faced significant challenges in seeking employment.
Finding an appropriate job was not straightforward. Barbara describes the experience: "When I finished my Ph.D. I received no support in finding a job. And I was also very naive. Now, when I think back about what happened to the people who finished about my time, there was clearly more going on with them than was going on with me. I was on my own and there was no doubt that an old boy's network was at work and it did not include me. But I didn't really know that at the time."12Because of this, there was a certain "randomness of the process" that Dr. Liskov describes as she began her career:
...I reacted to obstacles and opportunities. I believe that some of this was due to being a woman. When I was young, it was uncommon for women to think about having a career. The effect on me was that I just focused on doing work that was interesting but expected to stop working when I had a family. I thought about things in this way even after I had my Ph.D. However, as I got into my research in software systems I realized that I was really committed to my work and would not give it up. Later when my husband and I had a family, I continued to work full time. It's possible that my lack of focus on a career early on slowed me down, but it also freed me up to take advantage of opportunities that I otherwise might have missed.13The problems that Dr. Liskov faced had to do not only with opportunities, but with a certain ambivalence in the expectations placed on her as a woman by her family, herself, and the larger society.
I believe that I had a great deal of support from both my parents. This support took the form of encouragement for excelling academically, including excelling in math and science. But it did not include encouraging me to think about a career in these fields. Instead, I was supposed to have something to fall back on, such as teaching or being a secretary, in case I didn't marry or something happened to my husband. On the other hand, I was never told that "certain things shouldn't be done by women". I think this "ok" enabled me to follow my interest in math and science rather than settling on a more conventional direction.14It comes as no surprise, then, that Dr. Liskov has devoted a considerable amount of energy, creativity, and analytical acumen to providing a level playing field for other women who want to enter the computer science industry. During her tenure as associate head of the computer science department, five female computer scientists were added to the faculty.15 Dr. Liskov has been actively involved in MIT's efforts to recruit and retain more womnen and minority faculty. She co-chaired the Council on Faculty Diversity at MIT and was appointed as an Associate Provost for Faculty Equity in 2007, where she is working toward expanding the application pool for new faculty, actively recruiting promising candidates, including recent graduates, and ensuring that tenure and promotion is carried out fairly for women and minority professors.16
As an woman who fell into technology in way that seemed haphazard, almost accidental, I have tremendous appreciation for Dr. Liskov and all she has been able to achieve. Her brilliance, drive, and commitment to technical excellence in the face of significant discrimination and prejudice are an inspiration. I am humbled and awed by the resilience that must have been required to pursue a career at all, let alone such an unconventional one, in a world before Roe v. Wade, before women in some first-world nations (e.g., Switzerland) even had the right to vote, during a time when even her own perceptions of an appropriate role for women in the world was working against Dr. Liskov. I hope that it makes her recognition and success all the sweeter for her now.
Even if I can't make a lasting contribution of the field of information technology, I find a lot to admire in Dr. Liskov and hope that I can follow her example, striving for new and better solutions to technical problems, while advocating for women who come after me and making sure that fellow women in this field can succeed.
Selected sources consulted for this post (arranged alphabetically):
Cross-posted from my personal blog, World of Finches.