1964   Topological structures of the propositional calculus. 
           Lecture sponsored by the Philosophy Colloquium, with Sidney Axinn.  
           Temple University, Philadelphia, Pennsylvania, March 6.   
1966a  A new symbolism for the logic of sentences. 
            Presented to the Philosophy Club, with Derek Thomsett. 
            Acadia University, Nova Scotia, Canada, March 18.
1966b  The trinomial theorem and triangular coordinates as applied to 
            Sheldon's somatotypical tripology. 
            Presented at the annual meeting of the Canadian Psychological Association.
            Montreal, June 1-3.  [See Draft 1984]
1967   The Logic Alphabet. 
           Faculty Colloquium, with Gilbert R. Fischer.          
           Purdue University Calumet Campus (PUCC).
           Hammond, Indiana, March 10, April 7, and April 14.  Handout.
1975   Alternate notations for the propositional calculus. 
           Prepared for a Seminar at the School of Engineering, 
           Biological Computer Laboratory, with Heinz Von Foerster. 
           University of Illinois, Urbana, Illinois, October 10.  Handout.
1977   About and about: The Logic Alphabet. 
           Topic: Symbol systems, conventions, and rule-governed behavior. 
           N E H Summer Seminar, with Richard S. Rudner. 
           Washington University, Saint Louis, Missouri.  Three Handouts. 
1978a  Flipstick logic. 
            Presented to a class enrolled in college logic, with Nelson Pole. 
            Cleveland State University, Ohio, February 22.  Handout.
1978b  Sign-creation and man-sign engineering. 
            Presented at the annual meeting of the Semiotic Society of America.
            Providence, Rhode Island, October 6.  Handout.  [See Publication 1982b].
1979   A logical garnet as both a 3-D and a 4-D symmetry model of the 16 binary connectives. 
           In Program Abstracts, Sixth International Congress of Logic, 
           Methodology, and Philosophy of Science, Section 13, 205-209. 
           Hannover, Germany, August 22.  Handout.
1980   Designing signs that build the required semantics into the needed syntax.
           Presented at the annual meeting of the Semiotic Society of America, 
           Texas Tech University, Lubbock, Texas, October 17.  Handout.
1982   Classroom inventions for the Logic Alphabet. 
           Presented at the annual meeting of the Semiotic Society of America.
           Buffalo, New York, October 23.  Handout.  [See Publication 1987a].
1983a  More about the Logic Alphabet. 
            Center of Psychosocial Studies, with Milton Singer and Louis Kauffman. 
            Chicago, Illinois, June 30.  Handout.
1983b  Peirce's notations for the 16 binary connectives. 
            At the conference on: The birth of mathematical logic: 
            Nineteenth century logic from Boole to Schroeder. 
            Randall R. Dipert and John Corcoran (organizers), Department of Philosophy, 
            State University of New York, Fredonia, March 16-18.  Handout.
1985   Logic and sign creation: Catching up with Peirce (1902) and going beyond what he did (1985). 
           Charles Darwin Society, with Myrdene Anderson.
           Purdue University, West Lafayette, Indiana, October 11.  Handout.
1987a  Sensorimotor toys that work for Piaget's formal operations. 
            Topic: Tools and toys: Human implementation in evolutionary and cross-cultural perspective. 
            Symposium Abstracts for the annual meeting of the American Association for the 
            Advancement of Science, p. 59. 
            Chicago, Illinois, February 16.  Handout.
1987b  Peirce, Piaget, and actions-objects-symbols for the propositional calculus.
            Topic: Tools and toys: Representation. 
            Presented at the annual meeting of TASP: The Association for the Anthropological 
            Study of Play, Montreal, March 27.  Handout.
1987c  Notation, relational iconicity, and rethinking the propositional calculus. 
            In Program Abstracts, Eighth International Congress of Logic, Methodology, and 
            Philosophy of Science 1, 376-379. 
            Moscow, USSR, August 17-22.  Handout.
1988a  Symmetry, binary logic, and the game of flip-mate-flip. 
            In Denes Nagy (organizer and editor), Symmetry in a Cultural Context 2: 
            An Interdisciplinary Workshop, 17-21. 
            Arizona State University, March 18-20.
1988b  Sign-factors-engineered symbols for logic. 
            In Program Abstracts, An International Conference Celebrating the 50th Anniversary of  
            the Founding of the Institute of General Semantics, 25-26.  Yale University, July 27-31.
1989a  Symmetry and the crystallography of logic. 
            In Program Abstracts, Denes Nagy and Gyorgy Darvis (editors), 
            Symmetry of Structure: Interdisciplinary Symmetry Symposia 1I, 641-644. 
            Budapest, Hungary, August 13-19.  Handout
1989b  Untapped potential in Peirce's iconic notation for the sixteen binary connectives. 
            Presented at the Charles S. Peirce Sesquicentennial International Congress. 
            Harvard University, September 5-10.  Handout.  [See Publication 1997a]
1990   A Peircian approach to sign-building in logic. 
          Charles Darwin Society, with Myrdene Anderson.  Purdue University, 
          January 29.  Handout: The Logic Alphabet: Tables and diagrams.
1991   Comparative analysis of notations for the propositional calculus.          
           Workshop for classes in education, philosophy, and engineering. 
           Sponsored by Theodore Messenger at the University of North Dakota, 
           Grand Forks, North Dakota, April 18-20.
1992a  Cards, mirrors, and hand-held models that lead into elementary logic.
           Presented at the Sixteenth Annual Conference of the International Group 
            for the Psychology of Mathematics Education (North American Chapter),          
           University of New Hampshire, August 7-11.  Handout.
1992b  Semeiotics, good symmetry, and the logic of propositions. 
            In Gyorgy Darvis and Denes Nagy (editors), 
            Symmetry: Culture & Science (Special Issue), 76-77. 
            Hiroshima, Japan, August, 17-24.
1992c  Symmetry models that lead into elementary logic. 
            In Gyorgy Darvis and Denes Nagy (editors), 
            Symmetry: Culture & Science (Special Issue), 78-79. 
            Hiroshima, Japan, August, 17-24.
1993a  Symmetry, mirrors, and symbolic logic. 
            Faculty Colloquium, Mount Union College, 
            Alliance, Ohio, April 21.  Lots of overheads.
1993b  Extended Library Exhibit of the Models for the Logic Alphabet.
            Mount Union College, 
            Alliance, Ohio. Summer 1993.  Photographs.
1994   On a deep correspondence between sign-creation in logic and symmetry in crystallography. 
           At the Fifth Congress of the International Association for Semiotic Studies, 
           Berkeley, California, June 12-18.  [See Publications 1997b].
1995   A symmetry notation that coactivates the common ground between symbolic logic  
           and crystallography. 
           In Gyorgy Darvis and Denes Nagy (editors), Symmetry: Natural and Artificial, 556-559. 
           Third Congress of the International Society for the Interdisciplinary Study of Symmetry,
           Washington, D.C., August 14-20.  Handout.
1996   Sign creation, logic, and group theory. 
           In coordination with the 85th Birthday Celebration for Heinz Von Foerster 
           by the Institute Vienna Circle, November 13-14.   
           Institute for Advanced Studies, Vienna, November 12. 
1997   A personal record of how creativity in sign-factors engineering led to the Logic Alphabet. 
           Presented at the annual meeting of the Semiotic Society of America, 
           Louisville, Kentucky, October 23-26.  Lots of overheads.

1998a  Let the mirros do the thinking..
            Conference for Bridges: Mathematical Connections in Art, Music, and Science.
            Coordinated by Reza Sarhangi, Department of Mathematics, Southwestern College,
            Winfield, Kansas, July 28.  Lots of overheads.  [See Publications 1998].
1998b  Notation, square truth tables, and an introduction to mirror logic.
            Department of Mathematics and Computing, with Adam Vile. 
            South Bank University, London, September 22.  Lots of overheads.
1998c   Symmetry groups, relational polyhedra, and a much better notation for the
             propositional calculus. 
             The Mathematics Department, Kings College, London, September 24.

1999a  Elementary logic: A lesson in constructing a shape-value notation.
            The Department of Mathematics, with Adalira Saenz-Ludlow. 
            University of North Carolina at Charlotte, March 5.  Lots of overheads. 
1999b  Introduction to the Logic Alphabet. 
            For students and teachers of  mathematics at a public school. 
            Sponsored by Anna Marovich, Vicksburg Community Schools, 
            Vicksburg, Michigan, March 17.
2000   Symmetry and the importance of a shape value notation.  
           Geometry Conference: Recent trends in geometry and symmetry. 
           A conference in honor of Donald W. Crowe, University of Wisconsin, May 7.      

2003   Iconic Logic and Geometry (Roman Numeral I and Roman Numeral II).  
           Dynamic Geometry and Algebraic Physics
           with Louis H. Kauffman.
           University of Illinois at Chicago, March 31-April 4.