A very misused term. Today, an agent seems to mean a stand-alone piece of AIish software that scours across the internet doing something “intelligent.” Russell
and Norvig define it as “anything that can can be viewed a perceiving its
environment through sensors and acting upon that environment through effectors.”
Several papers I’ve read treat it as ‘any program that operates on behalf of a
human,’ similar to its use in the phrase ‘travel agent’. Marvin Minsky has yet
another definition in the book “Society of Mind.” Minsky’s hypothesis is that a large
number of seemingly-mindless agents can work together in a society to create an
intelligent society of mind. Minsky theorizes that not only will this be the basis of
computer intelligence, but it is also an explanation of how human intelligence
works. Andrew Moore at Carnegie Mellon University once remarked that “The only
proper use of the word ‘agent’ is when preceded by the words ‘travel’, ‘secret’, or
‘double’.”