2005.10.28
Human Thought and the Design of Computers
Peter J. Denning wrote an excellent article titled "The Locality Principle" in the July 2005 issue of the Communications of the ACM. The article explained the story behind the locality of reference, a fundamental principle of computing with many applications. In a comment that appeared in the October issue of the same magazine I commented:
Peter J. Denning's "The Profession of IT" column ("The Locality Principle," July 2005) invoked an anthropomorphic explanation for the prevalence of the locality principle in computational systems, observing that humans gather the most useful objects close around them to minimize the time and work required for their use, and that we've transferred these behaviors into the computational systems we design. A more intellectually satisfying explanation might be that we are dealing with two parallel and independent evolutionary design paths. Trading some expensive high-quality space (fast memory) in order to gain time performance is a sound engineering decision. It is therefore likely that evolution first adapted the human brain by endowing it with limited but versatile short-term memory and large long-term memory structure that exhibits behavior similar to caching. Millennia later, we make similar design decisions when building computing systems.The comment triggered an email exchange with Phillip G. Armour. It was one of the most intellectually satisfying email exchanges I've ever had, and I am reproducing it here, with his kind permission. Continue reading "Human Thought and the Design of Computers"
