Assessing the Impact of Jeff D Ullman Peter

Assessing the Impact of Jeff D. Ullman Peter P. Chen Computer Science Dept Louisiana State University Pchen@lsu. edu, www. csc. lsu. edu/~chen (Presented at Ullman’s Retirement Symposium, Stanford Univ. , Dec. 6, 2002)

Outline • How to assess the impact of a scientist? • Scope and Limitations of this study • Research Methodology and Tools • Research Results • Personal Note • Conclusions

How to Assess the Impact of a Scientist? • Usability – Actual Implementation, Tested in Real World – Number (or Percentage) of Users • Citation – Number of Citations of the Most Cited Paper – Number of Total Citations • Research Pioneering Leadership – Scope, number of papers, time length, – Number of the followers • Education Influence – Academic Family Tree; Productivity and Paper Citations of the nodes in the Family Tree – Book Leadership

Scope of this Study • Focusing on Jeff Ullman • Many speakers today already discussed the Usability and Research Pioneering Activity Dimensions, we did not do such study to avoid duplication • Concentrating on the Paper Citation and Education Influence Dimensions (including influence on me)

Research Methodology & Tools • Using Primarily “Cite. Seer, ” supplementing with other databases and search engines – Discovering various problems: many data errors, inconsistencies • Analysis of the Academic Tree posted at JDU’s home page & himself • Building an user interface to the database for simple queries • Comparing with the CS faculty in 5 universities

Education Influence of Jeff Ullman • Academic Family Tree – One of the Largest in Computer Science – Probably the largest in DB • Productivity and Citation Index of People in the Academic Tree – One of the Most Productive and Most Cited Group of Researchers • Book Leadership

Analysis of Data of Ullman’s Academic Family Tree • How many generations? • Which generation has most #people? – And what is the # of people? • What is the total number of nodes? • Which generation is most productive and influential (in terms of)? – Most number of publications/person – Highest average number of citations? • Who is the most – Productive? – Influential?

Analysis of Data of Ullman’s Academic Family Tree • How many generations? 5 • Which generation has most #people? 2 nd – And what is the # of people? 121 • What is the total number of nodes? 249 • Which generation is most productive and influential (in terms of)? – Most number of publications/person? 1 st, 18. 05 – Highest average number of citations? 1 st, 163. 34 • Who is the most – Productive? Howard Siegel, 373 – Influential? Larry Petterson (1985, 3 rd G. ) 1684, Student of D. Commer/R. Sethi

Comparisons of JDU’s Family with CS Depts • See separate spreadsheets (Note: the spreadsheets are not linked at this time. Will be linked in the near future)

How is Jeff ranked in the “Citation” Dimension? • Cite. Seer maintains two useful statistics – Most Cited Author – Most Cited Documents (including books and articles) • Warning: – Cite. Seer data contains a lot of errors – However, it is useful as a rough estimate, particularly for not very common last names

Cumulative Citations of Jeff Ullman’s Publications • Out of 629, 254 authors in the Cite. Seer DB • Jeff is ranked as No. 2 • The total number of citations of all Jeff’s publications is: 10592

Individual Publication Citations of Jeff Ullman • How many Jeff’s publications are ranked in the top 200 based on Cite. Seer Data as of September 2002? – Answer: 5

How many JDU’s publications are ranked in the top 200? • 12. Doc Context 1455 [4] John Hopcroft and Jeffrey Ullman. Introduction to Automata Theory, Languages, and Computation. Addison Wesley, 1979. • 21. Book Context 1171 [2] A. V. Aho, J. E. Hopcroft, and J. D. Ullman, The Design and Analysis of Computer Algorithms, Addison-Wesley, Reading, MA, 1974. • 26. Book Context 1107 [1] A. V. Aho, R. Sethi, and J. D. Ullman, Compilers: Principles, Techniques, and Tools. , Addison-Wesley, 1986. • 42. Doc Context 849 [Ull 88] Ullman J. D. : Principles of Database and Knowledge-Base Systems, Volumes 1 and 2. Computer Science Press, 1988. • 66. Doc Context 635 [23] A. V. Aho, R. Sethi, and J. D Ullman. Compilers Principles, Techniques and Tools. March 1988.

Book Leadership • JDM is the author or co-author of – 5 most cited books – Many best selling textbooks – Usually one of the first textbooks in a particular topic/field – “Model” textbooks for other textbook writers to follow

When did I meet with JDU the First Time? • ? ? ? • Need the help from Dave Maier and Alberto Mendelzon (two great historians) to dig out old historical data and compare notes. • Between 1974 to 1978, there was a DB workshop at Bell Lab. – JDM was there – Al Aho was there, too (? )

Reasons Why I am here • As a member of DB Community • As a person who have been benefited from his book leadership – Jeff’s book on “Principles of Database Systems, ” is probably the first book starting with the ER Model first – Other DB textbooks follow

Conclusions (1) • JDM has made very significant impact in computer science – Ranked No. 2 in total citations – 5 Most cited books and articles in top-200 cited publications – Best-Selling Book Author – One of the largest and most “productive” academic family tree • The DB community (particularly myself) has been benefited from JDU • Today, we pay tribute to him (to make an acyclic graph to a cyclic graph

Conclusions (2) • The DB community (particularly myself) has been benefited from JDU • Today, we pay tribute to him (to make an acyclic graph to a cyclic graph)

Conclusions (3) • We are here today to say to one of the greatest computer Scientists: “Dr. Jeff D. Ullman, Thank You!”