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Nick Gall's Weblog
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Saturday, June 12, 2004 |
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Friday, June 11, 2004 |
Another nail in the coffin of OMG's MDA.Saw this excellent article blogged by metamodel (itself an excellent resource). IMO, It very politely and constructively demolishes any hope that the OMG's Model Driven Architecture effort (especially PSMs--Platform Specific Models) will achieve any major benefits. I put my money on the more decentralized and federated approach of Domain-Specific Models (aka Domain-Specific Languages) (here's an upcoming workshop on the subject).
10:59:10 AM 
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Wednesday, June 09, 2004 |
The Futile Pursuit of Happiness.Nice summary of an interesting NY Times article a while back, which I meant to blog but didn't. Paul Kelly says it as well or better than I could, so here's his intro paragraph. The rest is highly worth reading. I'll see if I can get a link to the full NY Times article instead of the link to the pay-per-view archive.
This might also be entitled "the endless pursuit of happiness."
NYT Mag story by Jon Gertner about the work on "affective forecasting" by the psychologists Daniel Gilbert and Tim Wilson and the economists George Lowenstein and Daniel Kahneman. Can people accurately predict the outcomes of decisions which are supposed to make them happier? It turns out not. Things that are supposed to make us happy--dream job, dream house, dream car--don't as much as we hoped. Conversely, things we think of as disasters--death of a loved one, a disability--don't turn out to be as bad as we imagine. The implications for economics are obvious: how much does economic behaviour depend on this psychic "defect"? A lot, it turns out, and this has been known since the time of Adam Smith. Simply put, if you are comfortably off, the effort you expend trying to improve your situation is based on a delusion. It requires too much effort for too little payback. You are better off just as you are.
9:46:06 AM
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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
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