Designing Robots: Top-down v. Bottom-up

There are two fundamentally different models for building intelligent machines. Using the first strategy (Top-down), you decide what capabilities you want your robot to have and you write a sophisticated computer program (or programs) that 'builds in' all of those cognitive (mental) abilities from the outset. The result is typically a 'logical reasoning' engine that imposes control over the entire robot. The second strategy (Bottom-up), requires no such 'central control program'. Instead many simple (even 'stupid') mechanisms/programs are integrated into one machine. As these many simple devices begin to work in concert, they can produce behavior that is remarkably complex, even 'intelligent'. Our main efforts have thus far been in top-down robot design, but we are beginning a new project in bottom-up robot development. Which one (if either) is the best model for human and animal cognition is a matter of great controversy.