Grinnell College, Samuel R. and Marie-Louise Rosenthal Professor of Natural Science and Mathematics, 2001-present
Grinnell College, Professor of Mathematics and Computer Science, 1990-2001
Grinnell College, Professor of Mathematics, 1987-1990
Grinnell College, Associate Professor of Mathematics, 1980-1987
Grinnell College, Assistant Professor of Mathematics, 1974-1980
Massachusetts Institute of Technology, Department of Mathematics, Lecturer, 1973-1974
Williams College, Undergraduate Teaching Assisant for the Computer Laboratory, 1968-1969
University of Texas at Austin, Department of Computer Sciences, Senior Lecturer, 1988-1989, 1995
Bell Telephone Laboratories, Member of Technical Staff, 1980-1981
University of Texas at Austin, Department of Computer Sciences, Senior Lecturer, 1990, 1991, 1992, 1993, 1996
Mobil Oil Corporation, Computer Systems Analyst, 1969
Wesleyan University, independent study in mathematics (NSF), 1968
SIGCSE: The Special Interest Group on Computer Science Education of the Association for Computing Machinery
Member, CRA Study Group on Faculty Recruitment and Retention, 2001-present
Member, Iowa Advanced Placement Advisory Committee, 1996-present
Columnist on "Classroom Issues" for the SIGCSE Bulletin.
Panelist for the SIG Discretionary Fund, 1995-1996
Associate Editor for Computer Science Education for the Communications of the ACM , 1995-1996
Author and Program Director for Noyce Foundation grant to develop and lead workshops for high-school computer-science teachers, 1994-1996
Member of the
AP CS Ad Hoc Committee of the
College Board, 1995-1996, 1999-2000