"A Mathematical Analysis of a Three-Candidate Presidential Election," Mathematical Association of America, (1980). | |

"Music Synthesis on a Microcomputer," Maryland Association for the Educational Use of Computers, (1981). | |

"Measuring the Effectiveness of a Computer Network," Mathematical Association of America, (1982). | |

Chairman, Session on Computer Graphics, National Educational Computing Conference, (1983). | |

"A Computer Learning Algorithm," Mathematical Association of America, (1985). | |

"The Dempster-Shafer Theory of Evidence," The Johns Hopkins University, (1985). | |

"Should the Mathematical Association of America Become Involved in Questions of High School and Elementary School Mathematics Education?" Mathematical Association of America, (1985). | |

"Occurrences of Mathematics in Nature," The Lecture Group, (1985). | |

"Parsimonious Covering and Spreading Activation in Neural Nets," University of Maryland, (1986). | |

"The Goucher College Biographical Reference Advisor," Special Libraries Association, (1987). | |

"Building an Expert System," Eastern Small College Computing Conference (1987). | |

"Artificial Intelligence Illustrated," Goucher Center for Continuing Studies, (1988). | |

"DSM III-R: An Expert System for Diagnosis of Schizophrenic Disorders," Department of Psychiatry, University of Maryland School of Medicine, (1988). | |

"Expert Systems in the Educational Environment," EDUCOM (1988). | |

"REGIS, A Multi-technological Approach to Intelligent Documentation," Food and Agriculture Organization of the United Nations, (1989); Conference on Artificial Intelligence Research in the Environmental Sciences, (1990). | |

"Artificial Intelligence and Expert Systems in Communication," Special Libraries Association, (1989). | |

"The Impact of Artificial Intelligence, Expert Systems, Hypertext and Neural Networks in the Humanities," Goucher College Workshop for Teachers of English, Foreign Language, Social Science and Music, (1989). | |

"Artificial Intelligence in the Libraries," Military Librarians Workshop, (1990). | |

"The Origin of Time," Joint Meeting of the American Mathematical Society and the Mathematical Association of America, (1993). | |

"Surialism," Joint Meeting of the American Mathematical Society and the Mathematical Association of America, (1994). | |

"History of Mathematics in Jeopardy," Joint Meeting of the American Mathematical Society and the Mathematical Association of America, (1996). | |

"Mathematics and Sports," (Organizer of Special Session) Joint Meeting of the American Mathematical Society and the Mathematical Association of America, (1998, 2002). (Co-organized in 2002 with Howard Penn) | |

"Mathematics in Music," Invited Lecture, Bowie State University, (1998). | |

"Cryptology," Course Director, NSF Chautauqua Program, (Baltimore, MD, Memphis, TN, Bletchley Park, UK) (1998-2005). | |

"An Analysis of Scoring Algorithms in Professional Boxing," Joint Meeting of the American Mathematical Society and the Mathematical Association of America, (2002). | |

"Applications of Abstract Algebra," (Co-organizer of Special Session with George Mackiw ) Joint Meeting of the American Mathematical Society and the Mathematical Association of America, (2003). | |

“Random Walks,” Fourth Annual Kenneth C. Schraut Memorial Lecture, University of Dayton, November 1, 2003. | |

“Cryptology in Literature,” Invited Address, Loyola College in Maryland, March 24, 2004. | |

"Cryptology in Literature," Invited Address, Pennsylvania State System of Higher Education - Mathematics Conference, March 18, 2005. | |

"Classical Cryptology," Four Invited Addresses, Conference on Applied Mathematics, University of Central Oklahoma, June 10 - 11, 2005. | |

"Cryptology and the Breaking of the Axis Codes during World War II," Bletchley Park, England, August 1 - 4, 2005 and August 2 - 5, 2007. | |

"Cryptology," (Organizer of Special Session) Joint Meeting of the American Mathematical Society and the Mathematical Association of America, (2008 and 2009). (Co-organized with Chris Christensen) | |

"Tales from the Crypt: Adventure in Cryptology,” Invited Address, Maryland-District of Columbia-Virginia Section of the Mathematical Association of America, November 7, 2008. | |

"The Science of Keeping Secrets,” Invited Address, Loyola College Science Symposium, January 30, 2009. | |

"A Mathematical Tour of Baltimore," Joint Meeting of the American Mathematical Society and the Mathematical Association of America, (2010). | |

"A Final Project in an Elementary Cryptology Course," Joint Meeting of the American Mathematical Society and the Mathematical Association of America, (2012). |