The Letter Spirit project


Table of Contents

  1. A very short abstract
  2. Letter Spirit researchers
  3. Publications
  4. A PhD thesis
  5. Some sample gridfonts


An Emergent Model of the Perception and Creation
of Alphabetic Style

The Letter Spirit project is an attempt to model central aspects of human high-level perception and creativity on a computer. It is based on the belief that creativity is an automatic outcome of the existence of sufficiently flexible and context-sensitive concepts --- what we call fluid concepts. Accordingly, our goal is to implement a model of fluid concepts in a challenging domain. Not surprisingly, the Letter Spirit project is a very complex undertaking and requires complex dynamic memory structures, as well as a sophisticated control structure based on the principles of emergent computation, wherein complex high-level behavior emerges as a statistical consequence of many small computational actions. The full realization of such a model will, we believe, shed light on the mechanisms of human creativity.

The specific focus of Letter Spirit is the creative act of artistic letter-design. The aim is to model how the 26 lowercase letters of the roman alphabet can be rendered in many different but internally coherent styles. The program addresses two important aspects of letterforms: the categorical sameness possessed by letters belonging to a given category ( e.g., `a') and the stylistic sameness possessed by letters belonging to a given style ( e.g., Helvetica). Starting with one or more seed letters representing the beginnings of a style, the program will attempt to create the rest of the alphabet in such a way that all 26 letters share that same style, or spirit.


Letter Spirit researchers

Work on the Letter Spirit project is being done by Gary McGraw and John Rehling (under Douglas Hofstadter's guidance). Gary implemented Letter Spirit's gridletter recognizer (the Examiner also called the ``role model'') for his PhD. Gary's thesis is available on the net.

The Letter Spirit articles archive

Many of these articles are listed along with abstracts in Gary McGraw's publications archive.
  1. Probably the best source of information on Letter Spirit is the new book Fluid Concepts and Creative Analogies. Chapter 10 is devoted exclusively to the Letter Spirit project.

  2. Gary McGraw, John Rehling and Robert Goldstone. (1994) Letter Perception: Toward a conceptual approach, In the Proceedings of the Sixteenth Annual Conference of the Cognitive Science Society, pages 613-618, Atlanta, GA, August 1994.

    An expanded version of this research is also available, and has been submitted for journal publication.

  3. Gary McGraw and Douglas R. Hofstadter. (1993) Letter Spirit: An Architecture for Creativity in a Microdomain. In Advances in Artificial Intelligence: Third Congress of the Italian Association for Artificial Intelligence (AI*IA 93), P. Torasso (ed.), pages 65-70, Torino, October 26-8, 1993.

    Not available electronically. See the AAAI paper (below) for a similar article.

  4. Gary McGraw and Douglas R. Hofstadter. (1993) Perception and Creation of Alphabetic Style. In Artificial Intelligence and Creativity: Papers from the 1993 Spring Symposium, AAAI Technical Report SS-93-01, AAAI Press.

  5. Gary McGraw and Douglas R. Hofstadter. (1993) Perception and Creation of Diverse Alphabetic Styles. In Artificial Intelligence and Simulation of Behaviour Quarterly, Issue Number 85, pages 42-49. Autumn 1993. University of Sussex, UK.

  6. Gary McGraw and Daniel Drasin. (1993) Recognition of Gridletters: Probing the Behavior of Three Competing Models. In Proceedings of the Fifth Midwest AI and Cognitive Science Conference, pages 63-67, April 1993.

  7. Douglas Hofstadter and Gary McGraw. (1993) Letter Spirit: An Emergent Model of the Perception and Creation of Alphabetic Style. Technical Report 68, Center for Research on Concepts and Cognition, 510 North Fess, Bloomington, IN 47405, January 1993.

  8. Gary McGraw. (1992) Letter Spirit: Recognition and Creation of Letterforms Based on Fluid Concepts. Technical Report 61, Center for Research on Concepts and Cognition, 510 North Fess, Bloomington, IN 47405, June 1992.

    Not available electronically.


A Letter Spirit PhD Thesis

Gary McGraw's thesis is the first major body of work devoted to Letter Spirit. The thesis aims to do two things: 1) provide a philosophical underpinning to the project and sketch its general architecture, and 2) thoroughly discuss Letter Spirit's implemented letter recognition module.


Some sample gridfonts

Several human designed gridfonts illustrating the two fundamental ideas behind the Letter Spirit project --- stylistic sameness and letter category sameness. These gridfonts also show the richness of the Letter Spirit microdomain.


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