Ingo Wegener (1950-2008)

Philipp Woelfel remembers his advisor.

"Doktorvater" (doctor father) is the unofficial German term for PhD adviser – from my perspective, I can't think of a better word to describe my PhD adviser, Ingo Wegener, who passed away on November 26, 2008, after a long battle with cancer.

Probably many readers of this blog know about Ingo's work in complexity theory. Exemplary for his research are the topics of two of his monographs: The Complexity of Boolean Functions, 1987 (known to most of us simply as the Blue Book), and Branching Programs and Binary Decision Diagrams – Theory and Applications, 2000. Probably less known in this community is that about 10 years ago, Ingo began to investigate and analyze randomized search heuristics (evolutionary algorithms). Ingo and his research group strongly influenced the theory of this area; previously research was primarily experimental.

Ingo has been recognized as an outstanding scientist. He was a member of the "Wissenschaftsrat" (the most important scientific advisory committee of the German government), a member of the German Academy of Sciences Leopoldina, and the Academy of Sciences of Nordrhein-Westfalen. In 2006 he was awarded the Konrad-Zuse-Medal, the most prestigious German computer science award.

Here are some things I remember about Ingo (hopefully, some readers can add their recollections to the comments).

• Ingo always wrote his scientific texts by hand. And Ingo was an incredibly efficient writer: when he was writing his recent textbook Complexity Theory: Exploring the Limits of Efficient Algorithms, the students who were LaTeXing the manuscript, as well as those who were proof-reading it, used to complain that Ingo was preparing the manuscripts too fast for them to keep up. (Ingo was on Sabbatical, though.)
• Ingo was a gifted teacher. The students of the University Dortmund had an evaluation system, where each term they would elect the worst teacher, who would then be called "Lehrer Lempel" (sorry, probably only Germans understand the term). Ingo's lectures were known to be most difficult. Despite this, he usually came out "last" in the contest without any chance of ever winning the infamous "Lehrer Lempel" cup. In fact (according to Wikipedia) Ingo won the (real) teaching award of the University Dortmund twice.
• One of my favorite quotes is this. Asked about the difficulty of exams, he replied by asking whether anyone, who couldn't distinguish a kidney from a liver should be allowed to graduate from medical school...
• Ingo was one of the best organized people I have ever met. When I handed in my PhD thesis, Ingo said he'd be going to a workshop the next day, but he would write the report after returning. Sure enough, he came back from the workshop 5 days later, with the report on my thesis in his bag (and he wasn't a co-author of any of its papers).

We have lost an outstanding researcher, teacher, adviser, and friend, who for me was a true "Doktorvater".