It's a milestone. It's not a finish line!
As of June 1, 2024, I am an Emeritus Professor in the Department of Electrical Engineering and Computer Science at the University of Michigan. I still hang around with friends and colleagues in Computer Science and Engineering and in the Department of Robotics.
I don't plan to stop working, of course. The major research focus for the next phase of my career is Ethics for AI and Robotics.
I am no longer taking on new students, though I am helping a few students complete their degrees, and I am always happy to talk about research topics in and around AI (which means, about pretty much anything). I am no longer taking a leading role in applying for grants to support research and students, though I am happy to help colleagues with their proposals.
I discovered the field of Artificial Intelligence in Spring 1973, during my first year as a grad student in pure math at MIT. I had planned to be a pure mathematician, but the skies opened, and I saw AI as being the kind of mathematics needed to model the mind. I ended up working on modeling commonsense knowledge of foundational domains such as space, dynamical change, objects and actions, and now ethics.
Over the years, I have written several essays reflecting on various topics I have worked on. I have also written a lot of papers since then, so I have selected out some Highlights.
My research on commonsense knowledge of large-scale space (sometimes called navigational space, or the cognitive map) has been an important part of my life since my graduate studies. In 2008, I wrote a reflection on that work called An Intellectual History of the Spatial Semantic Hierarchy.
Of course, there was a lot more detailed work before and after that point, so here is a complete list of my papers in that area.
My research on commonsense reasoning about dynamic change has produced the QSIM representation and qualitative simulation algorithm. These are described briefly in a 2001 encyclopedia article, in depth in a book, Qualitative Reasoning: Modeling and Simulation with Incomplete Knowledge (MIT Press, 1994) and in many papers.
Here are two 1993 retrospectives on qualitative representations and qualitative simulation.
My essay Why don't I take military funding? describes the background for my transition from cognitive mapping research to qualitative reasoning research. The connections to my current work on AI Ethics are also pretty clear.
There are a number of topics I have looked into for a while, often motivated by a particular insight or idea, but then have moved on. I have a lot of affection for these ideas, and I am happy to encourage other people to carry them forward if they are interested. I am unlikely to spend much more time on them, but you never know.
Consciousness is a fascinating aspect of the mind, so AI has potential relevance. This paper responds to a challenge by John Searle, arguing that computational methods like AI and developmental robotics do have something valuable to contribute to the problem of consciousness.
Access-Limited Logic and its implementation as a knowledge representation and inference language called Algernon, are an attempt to define a version of logic programmming running over semantic networks (such as Minsky's notion of "frames"). It has both nice theoretical properties and nice intuitions for representing knowledge in the GOFAI tradition.
The Swan's Neck manipulator addresses the problem of planning manipulator motion for a continuous (rather than segmented and jointed) manipulator. This avoids some of the complexity problems of traditional manipulator models.
Wisdom from others who have gone before me into this "retirement" job suggests that there will be no shortage of things to do. Their advice is to wait a year or so before making new commitments.
We're not planning to move anywhere. There are plenty of family, friends, and things to do around here. (And climate change projections suggest that Michigan will continue to be a good place to be.)
I remain quite fond of many of the topics I've explored in the past, and it seems that there remains plenty to say about them. I plan to keep reading, writing, and talking about these things as long as I can.