Slides for Lectures

A collection of slides presented by John Sowa in various lectures. The last slide in each set has a list of suggested readings, including other slides or publications on related topics. For an overview of problems and issues in artificial intelligence, the following two are good starting points:

The complete bibliography for all web pages on this site is available at

Note:  To maximize the slides to fill the screen, use the Adobe reader and press CTRL-L. To return to the normal Adobe mode, either press ESC or press CTRL-L a second time.

Pursuing the Goal of Language Understanding

These slides are an expanded version of the slides for a talk presented in the Stanford Media X Lecture Series on 8 December 2008. An earlier version of these slides was presented at ICCS'08 in Toulouse, France, in July 2008. A two-lecture expanded version was presented in October 2008. For further background on related issues, see the Three Lectures on Semantic Technology.

Two Lectures on Dynamic Ontology

Two lectures on a Wittgensteinian approach to language understanding by computer and its implications for ontology. Presented at the University of Edinburgh in October 2008.

  1. A Wittgensteinian Method of Relating Language to the World.

  2. Using a Society of Agents to Interpret Natural Language.

Common Logic

An introduction to the Common Logic standard (ISO/IEC 24707) and Common Logic Controlled English (CLCE). Presented at the Semantic Technology conference in San Jose, CA, in May 2008.

Three Lectures on Semantic Technology

Three lectures on issues of semantic technology and their foundations in artificial intelligence and computational linguistics. Presented at MIMOS Berhad in Malaysia in March 2008.

  1. Semantic Technology.

  2. Logic, Ontology, and Analogy.

  3. The Goal of Language Understanding.

Logic and Ontology as Abstractions from Language

Contrary to assumptions that logic is the foundation for semantics, the evidence indicates that language is prior to logic and ontology, and both of the formal systems are abstractions from linguistic patterns. This talk was presented at a workshop on ontology in Bolzano, Italy, in September 2007.

Concept Mapping

Problems of knowledge representation and the use of informal methods, such as concept mapping. This talk was presented at the AERA Conference in San Francisco in April 2006, in the track on Technology, Instruction, Cognition and Learning.

Peirce’s Contributions to the 21st Century

An overview of the research by Charles Sanders Peirce in logic, semiotics, linguistics, lexicography, and philosophy and its relevance to current research trends. This talk was presented at the ICCS'06 Conference in Aalborg, Denmark, in July 2006.

The Challenge of Knowledge Soup

Problems and issues that have plagued artificial intelligence for the past half century. Versions of this talk were presented at several locations. The last one was the Episteme-1 Conference in Goa, India, in December 2004. A paper with the same title was published in 2006.

Copyright ©2008, John F. Sowa