Skip (Clarence A.) Ellis

born: 1943; place: Chicago

B.S. Mathematics and Physics (1964) Beloit College

Ph.D. (1969) Computer Science University of Illinois
thesis: Probabilistic Languages and Automata; advisor: Professor David Muller.

: Professor of Computer Science, and Director of the Collaboration Technology Research Group at the University of Colorado at Boulder

email: email:

Clarence "Skip" Ellis was born in 1943 and grew up in a very poor neighborhood of the south side of Chicago. His mother struggled to raise five children by herself. Gangs and violence were common in school. Skip wasn't one of the "cool" kids - he mostly kept to himself. At the time, he was sad because he felt excluded from so many things. Surprisingly, this helped him because he was able to avoid the gangs, violence and problems some kids in his class got into.

At 15, Skip took a job at a local company to help support his family. He was assigned the "graveyard shift," which meant he had to work all night long. His job was to prevent break-ins and, most importantly, not to touch the company's brand new computer! It was 1958 and computers were very expensive and not very common. Since he had lots of free time, he read the computer manuals that came with the machines. He became a self-taught computer expert. One day, there was a crisis at the company. They had an urgent project but had run out of new punch cards. Early computers used punch cards to enter data and without new cards, the project came to a halt. Skip was the only one who knew how to reuse old cards. He changed some settings on the computer and the old cards worked perfectly. He was a hero for a day! This was his first real experience with a computer and it changed his life.

Over the next couple of years, teachers recommended that Skip attend summer programs at local universities. For the first time, Skip met students outside of his neighborhood and became aware of university life. Skip's family couldn't afford to send him to college. But, as he was about to graduate from high school, the pastor in his family's church learned about a scholarship at Beloit College. Beloit is located in Wisconsin, about 100 miles northwest of Chicago. Skip won the scholarship and, in the fall of 1960, arrived on campus. He discovered that he was the only African-American attending the school! Life in south Chicago was hard, but this was much worse. He felt very alone. He soon learned that his classes were much more difficult than any of those at his high school. Everyone seemed smarter, more aware and better educated.

At Beloit, a teacher gave Ellis extra lessons in the subjects that Skip was finding the most difficult, such as English. He studied constantly and had no time to do many of the fun things that other students seemed to enjoy. He even stayed on campus to study during winter and summer breaks. Skip was so sad and lonely that he thought about quitting many, many times. But he knew how proud his mother was of his accomplishments. She had constantly encouraged him, saying, "be your own person and follow your talents." He vowed to stay.

At the beginning of his junior year, a computer was donated to the college. Skip and his chemistry professor were given the task of setting it up. This was the start of the college's computer lab, and it was a big event in Skip's life - he finally felt like he belonged. He worked so long on the new computer that he sometimes slept overnight in the lab.

During this period of time, the civil rights movement was gathering momentum across the country. Skip was especially moved by the non-violent protests of Dr. Martin Luther King. In August of 1963, Skip was one of 250,000 people who went to Washington, D.C., to hear Dr. King give his famous "I Have a Dream" speech from the steps of the Lincoln Memorial. From then on, Skip's passions were computer science and civil rights.

In 1964 he received a BS degree, double major in math and Physics, from Beloit College. Clarence (Skip) Ellis attended graduate school in Computer Science from the University of Illinois where he worked on hardware, software, and applications of the Illiac 4 Supercomputer. Clarence Ellis is the first African American to receive a Ph.D. in Computer Science (1969).

After his Ph.D., he continued his work on supercomputers at Bell Telephone Laboratories. Ellis has worked as a researcher and developer at IBM, Xerox, Microelectronics and Computer Technology Corporation, Los Alamos Scientific Labs, and Argonne National Lab.

His academic experience includes teaching at Stanford University, the University of Texas, MIT, Stevens Institute of Technology, and in Taiwan under an AFIPS overseas teaching fellowship.

Currently, Dr. Ellis is a Professor of Computer Science, and Director of the Collaboration Technology Research Group at the University of Colorado at Boulder. At Colorado, he is a member of the Systems Software Lab, and the Institute for Cognitive Science.

During 1991, he was chief architect of the FlowPath workflow product of Bull S.A. Previously he was the head of the Groupware Research Group within the Software Technology Program at MCC. For the decade prior to joining MCC, he was a research scientist at Xerox Palo Alto Research Center.

Clarence (Skip) Ellis is on the editorial board of numerous journals, and has been an active instigator and leader of a number of computer associations and functions. He has been a member of the National Science Foundation Computer Science Advisory Board; of the University of Singapore ISS International Advisory Board; of the NSF Computer Science Education Committee; and chairman of the ACM Special Interest Group on Office Information Systems (SIGOIS).


Dr. Skip Ellis has worked as a researcher and developer at Bell Telephone Laboratories, IBM, Xerox, Microelectronics and Computer Technology Corporation, Los Alamos Scientific Labs, and Argonne National Lab. He has published several books, and over 100 technical papers and reports, lectured in more than a dozen countries, and was an invited speaker on object oriented systems at the most recent IFIP World Computer Conference. His interests include groupware, coordination theory, object oriented systems, CSCW, office systems, databases, distributed systems, software engineering, world-wide-web (internetworking), systems design and modeling, workflow systems, and humane interfaces to computers.


1. Ellis, Clarence A. Participatory Design in Groupware Systems. Proceedings of the Groupware'96 Conference, August 1996. 44-52.

2. Ellis, Clarence A. A Workflow Architecture to Support Dynamic Change. Workshop on Distributed Systems, Multimedia, and Infrastrtucture, March 1995. 23-30.

3. Ellis, Clarence A. Goal Based Workflow Systems. International Journal of Collaborative Computing, 1,no.1, 1994. pp.61-86.

4. Ellis, Clarence A. Technological Challenges in Groupware. Proceedings of the Third International Workshop on Intelligent and Cooperative Information Systems, April 1992. pp.121-132.

5. Ellis, Clarence A.; S. Gibbs; G. Rein Groupware: The Research and Development Issues. Communications of the ACM, 34,1, 1991.

6. Ellis, Clarence A.; G. Rein rIBIS: A Real Time Group Hypertext System. International Journal of Man Machine Systems, 34 (1991), 21-51.

7. Yeh, Show-Way; Ellis, Clarence A.; Ege, Aral; Korth, Henry F. Performance analysis of two concurrency control schemes for design environments. (English) [J] Inf. Sci. 49, No.1-3, 3-33 (1989).

8. Ellis, Clarence A. Probabilistic models of computer deadlock. Inform. Sci. 12 (1977), no. 1, 43--60. 68B20 (68D25 68J10)

9. Ellis, Clarence A. Analysis of some abstract measures of protection in computer systems. Internat. J. Comput. Inform. Sci. 7 (1978), no. 3, 219--251. 68B20

10. Ellis, Clarence A. Optimal scheduling of homogeneous job systems. Information Sci. 9 (1975), no. 4, 323--358.

11. Ellis, Clarence A. The halting problem for probabilistic context-free generators. J. Assoc. Comput. Mach. 19 (1972), 396--399.

12. Ellis, Clarence A. Probabilistic tree automata. Information and Control 19 (1971), 401--416.

references: Dr. Ellis' web pages:;

Computer Scientists of the African Diaspora

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