Michigan State University
- Research Associate 1985-1987
- Visiting Assistant Professor 1987-1988
- Assistant Professor 1987-1992
- Associate Professor 1992-1997
- Professor 1997-2003
- Cincinnati Professor of Mathematics 2003-2012
- Mathematics Department Head 2009-2011
- Summer-school faculty 2012, 2014
- Visiting Professor of Mathematics 2012-2013
- Visiting Professor of Mathematics 2013-2014
- Lectuere, Director of Lower Division Courses 2015-2018
-
Professor, General Faculty, Director of Lower 2018-
Division Courses
- Summer-school faculty 2016