Tuesday, June 08, 2004

Tight coupling means tight tolerances. Most discussions of tight/loose coupling focus on the degree of information sharing across the interface. Here's an additional perspective that came out of a discussion with my colleague, Tom Murphy. The tradeoff between tight and loose coupling is the trade off between efficiency (performance) and "robustness". Tightly-coupled systems are more "fragile" in that they "break" when a input is not "within tolerance," e.g., did not arrive fast enough, has an error in it. The "tight" in tightly-coupled actually refers to "tight" tolerances for errors. Loosely-coupled systems have loose tolerance for errors (more and/or bigger). The most robust systems impose tight tolerances on output, but impose only loose tolerance of imput. By doing so, such systems "amplify correctness." In other words, they are anti-entropic amplifiers. 3:55:01 AM    comment []  trackback []