[Photo of Bob Hearn]

Bob Hearn

My current webpage is here, at Dartmouth College.

This page is no longer maintained.

I am currently a graduate student in the Artificial Intelligence Laboratory at MIT.


I'm in Project MAC (a research group with a long and interesting history); my research advisor is Gerry Sussman.

My main research interest lies in satisfying the traditional goal of artificial intelligence: building programs that think the way people do. Much current AI work, by contrast, is focused on real-world applications of AI techniques.

My primary source of inspiration is Marvin Minsky's book The Society of Mind. This book gives what I think is the best insight yet on how minds could work, and some of the tools one might use to build one. Although this is a popular book, and many people are at least acquainted with the ideas, as far as I know I am the first person to have actually taken them at face value and used them to build an AI system. My first effort in this direction is described in my Master's thesis:

New: If you use a Mac, you can play with the program I wrote for this thesis. (Sorry, there's no documentation! Email me if you have questions.)

For my Ph.D. I am working on a much more elaborate system. This involves simulated creatures in a physically robust two-dimensional world (inspired by A. K. Dewdney's Planiverse), controlled by programs written in a Society of Mind-inspired programming language. Here is my thesis proposal:

I also think there is a lot of value in the ideas behind behavior-based robotics; I use these ideas as inspiration as well. However, I do not subscribe to the embodied AI doctrine that an AI system must necessarily be incarnated (so to speak) in a physical robot to achieve human-level intelligence.

Here are some slides from a Dangerous Ideas Seminar talk I recently gave at MIT:

Other Research

I've always been fascinated by games and puzzles, and also by the more mathematical side of theoretical computer science (computability and complexity theory). Recently I found a way (thanks Erik) to integrate these interests, by studying the computational complexity of games and puzzles. The most interesting thing I've discovered to date is that traditional sliding-block puzzles are PSPACE-complete. You know, the kind where you have a box of wooden rectangular pieces, and you have to slide them around to get one to a particular place. Well, it turns out you can effectively build computers out of them! For an introductory explanation of this idea (as well as constructions showing that plank puzzles are also PSPACE-complete), see: This work is also discussed in a recent Science News article by Ivars Peterson. For a more technical presentation of these results, see the first paper below. The second describes another application of the same proof technique.

Professional Work

Prior to entering grad school I spent several years in the real world, during which I co-wrote the Macintosh program ClarisWorks. Before that I worked on some less well-known software, such as TopDraw and AppleWorks GS. After ClarisWorks I did a brief stint at Gobe, where I worked on a novel constraint-based programming paradigm.

Other Interests


I am married to Liz Hearn. She is an assistant professor in the Earth and Ocean Sciences department at The University of British Columbia. (Thus, I'm finishing my MIT Ph.D. remotely, from beautiful Vancouver.) She runs big hairy earthquake simulations.

My parents have a page with some family history.

We have two cats, Grimalkin and Euclid. They were born two days before we were married, in 1987. They are thus getting to be elderly kitties, but for the most part they don't show it!

Here is an older personal page with some family pics. (These show me pre-Hacker's diet. No, this is not a joke, as some people who've read my page seem to think. The Hacker's diet is a legitimate, commonsense diet, and yes, those pictures really are of me!)

Contact Information

Copyright © 1969 Robert A. Hearn

Last Modified: December 31, 1969
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