Efficient Search and Indexing (Former Research Group)

The research group "Efficient Seach and Indexing", headed by Hannah Bast, was part of the Cluster of Excellence MMCI from October 2007 until December 2009.

Vision and Research Strategy

We do applied algorithmics. In a nutshell, that means that we consider real-world problems that are algorithmically challenging, and that we aim for solutions that work in practice. Our work encompasses classical theoretical algorithm design and analysis, algorithm engineering and experimentation, as well as professional system design and software engineering. We pride ourselves on developing our research results to the level of actual products, some of which are used by millions of people worldwide.

This product orientation has a great impact on the way we select and define our research problems and the way we tackle them. In particular, problems are not well-defined and fixed from the outset, as in classical theoretical computer science. Rather, they are "moving targets" in the sense that it's a significant part of our research to find adequate problem formulations which lead to practically viable solutions while also being theoretically feasible.

In the past years, we have focused on two application areas. One of these is the area of information retrieval. We do research on all facets of information retrieval, with an emphasis on reconciling complex functionality with high scalability. In a nutshell, we aim to make intelligent search fast. Our second main application area is fast route planning on large transportation networks.

Composition of Group

The period up to the end of 2010 was special in several respects:

  1. I visited Google Zurich for an extended period of time, from mid 2008 to mid 2009. This appointment was originally planned for half a year, but since my project there went so well, and needed me, I prolonged it to over a year.
  2. During my stay at Google, I received three offers: for a full professorship (W3) at the University of Mainz, for a full professorship at the University of Freiburg (W3), and for a full-time research position at Google. I eventually accepted the offer from Freiburg, where I started work on September 15, 2009.
  3. Due to the combination of being away from the institute and from the Cluster for an extended period of time and then knowing that I would leave Saarbrücken 2009 for one position or the other, I stopped hiring people in my group, and since 2008 had only a single Ph.D. student: Marjan Celikik. Two of my former Ph.D. students, Debapriyo Majumdar and Ingmar Weber, successfully defended their thesis and left. I did, however, collaborate with a lot of people outside of my own group.
  4. Our group's work received a number of prestigious awards in the period covered by this report, including the Meyer-Struckmann-Science Award and the Alcatel-Lucent Award for Technical Communication. I also received two awards for my work on route planning (together with Stefan Funke).

Research Topics and Achievements

Projects and Collaborations

Prizes and Awards

Prof. Dr. Hannah Bast

Prof. Dr. Hannah Bast

Hannah Bast is a full professor at the department of computer science of the University of Freiburg, and head of the Chair of Algorithms and Data Structures.

Fon: +49 761 203-8163