As March comes to an end, I wanted to feature someone in honor of Women’s History Month, one of the women behind the L of SOLID principles.
Dr. Barbara Liskov - the L in SOLID principles
Dr. Barbara Liskov is the Liskov in the Liskov substitution principle. She - along with Jeannette Wing - is responsible for the L principle of SOLID principles. This principle means that the subclasses (or derived classes) should be able to replace the base classes with unaffected behavior. She presented this in her OOPSLA 1987 keynote titled Data abstraction and hierarchy.
I’ve always looked up to Dr. Liskov’s work through her career. What I appreciate the most is that Dr. Liskov did not stay in one part of technology. When she pursued her Ph.D., she focused on Artificial Intelligence. Later on in her career, she would do research in systems, programming languages, and distributed systems. Seeing how she continually researched in tech and continued to push the industry forward is inspiring. I really admire that her research and work in the classroom have been focused on how to make better software. I also admire that she was able to continue her work in the field while also having a family.
Dr. Liskov’s Ph.D. was done at Stanford University, focused on a computer program to play chess endgames. This was done in 1968 - so we’re not talking about AI like Watson, ChatGPT, or Bard. Her AI work was done early on, and she is recognized as a pioneer in the industry.
Other contributions from Dr. Liskov include:
- Venus operating system - experimental programming system that supported up to six users concurrently on a small computer
- Design and implementation of the CLU programming language - CLU files, 1976-1989 (GitHub)
- Design and implementation of the Argus programming language - which supported implementing and executing distributed programs
- Thor - an object-oriented database system
- Byzantine fault tolerance
Awards
Dr. Liskov’s contributions to the technical fields have led to many accolades from organizations including the Society of Women Engineers (SWE), the Association for Computing Machinery (ACM), and the Institute of Electrical and Electronics Engineers (IEEE). Her awards include:
- 1996 - SWE - Achievement Award
- 2004 - IEEE - John von Neumann Medal
- 2008 - ACM - A. M. Turing Award
- 2012 - National Inventors Hall of Fame
- 2018 - IEEE - Computer Pioneer Award
Career Advice
In this interview with Dr. Ming Lin, vice chair of the CS awards committee of IEEE, Dr. Liskov shares these words of advice about a career in tech:
“It’s really important to know what you don’t know as well as what you do know. If you really enjoy teaching and research, then an academic career is a good choice for you… It may turn out that you really enjoy management. You really enjoy… product development… Everybody has to figure this out for themselves. As long as you pay attention to what you like and what you’re good at, I think you’ll have a successful career.”
Conclusion
Thank you, Dr. Liskov, for all of your contributions to the tech world and for being an inspiration for many of us in tech.