Title: "Oh sure, my method is connectionist too. Who said it's not?"

Panel Organizers: Ron Sun, Bruno Appoloni, and Asim Roy

Decription:
Some claim that the notion of connectionism is an evolving one. Since the
publication of the PDP book (which enumerated the then accepted principles
of connectionism), many new ideas have been proposed and many new
developments have occurred. So according to these claims, the connectionism
of today is different from connectionism of yesterday. Examples of such new
developments in connectionism include hybrid connectionist-symbolic models
(Sun 1995, 1997), neuro-fuzzy models (Keller 1993, Bezdek 1992),
reinforcement learning models (Kaelbling et al. 1994, Sutton and Barto
1998), genetic/evolutionary algorithms (Mitchell 1994), support vector
machines (Vapnik 1998), and so on. In these newer connectionist models,
there are many violations of the "older" connectionist principles. One of
the simplest violations is the reading and setting of connection weights in
a network by an external agent in the system.  The means and mechanisms of
external setting and reading of weights were not envisioned in early
connectionism.  Why do we need local learning laws if an external source can
set the weights of a network? So this and other features of these newer
methods are obviously in direct conflict with early connectionism.

In the context of these algorithmic developments, it has been said that
maybe nobody at this stage has a clear definition of connectionism, that
everyone makes things up (in terms of basic principles) as they go along. Is
this the case? If so, does this pose a problem for the field? To defend this
situation, some argue that connectionism is not just one principle, but
many? Is that the case? If not, should we redefine connectionism given the
needs of these new types of learning methods and on the basis of our current
knowledge of how the brain works?

This panel intends to closely examine this issue in a focused and intensive
way.  Debates are expected. We hope to at least clarify some fundamental
notions and issues concerning connectionism, and hopefully also make some
progress on understanding where it needs to go in the near future.