Jeff drawn by Damien
portrait by Damien Erickson (2018)

I'm a computational geometer/topologist/graphophile with more general interests in algorithms, data structures, and lower bounds, and with growing interest in computer science education research. I teach mostly large algorithms classes; you might find my free textbook and other course materials useful. Almost half of my former graduate students have tenure, and almost half of my former PhD students have won NSF CAREER awards. I am the lead SafeTOC advocate for SODA, a SafeTOC advocate for SOCG, and a member of my department's CS CARES committee. I am also the chair of my department's internal faculty advisory committee.

I have the lowest undergraduate GPA (2.4/4.0) of any professor I've ever met, although some of my colleagues came close, and a few others never finished college at all. (I really shouldn't be proud of that.) Only two other professors have been faculty in my department longer than I have, but several others were students here before I arrived. (I really shouldn't be proud of that, either.) I have been known to give unsolicited advice.

Praxis tendatum docebit. [Practice will teach those who try.]
— Carl Friedrich Gauß, describing the fast Fourier transform (c. 1805)

Man muß jederzeit an Stelle von „Punkte, Geraden, Ebenen“ „Tische, Stühle, Bierseidel“ sagen können. [One must always be able to say “tables, chairs, beer mugs” in place of “points, lines, planes”.]
— David Hilbert to Otto Blumenthal, on the axiomatic method in mathematics

I believe in the third dimension, but not the other two.
James "Kibo" Parry

They say that I have no hits and I'm difficult to work with, and they say that like it's a bad thing.
Tom Waits, at his induction into the Rock and Roll Hall of Fame (2011)

As we all know, the easiest way to be at the top of your field is to choose a very small field.
Simone Giertz, "Why you should make useless things" (2018)