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I think people are attracted more to the form of the EWDs and to it's melancholic tone, rather than to the content itself, which is confirmed by the huge popula

by stiff 13y ago

I think people are attracted more to the form of the EWDs and to it's melancholic tone, rather than to the content itself, which is confirmed by the huge popularity of the EWDs as compared to "The discipline of programming", which is the technical exposition of what Dijkstra really is proposing in the EWDs. As almost all of Dijkstra's writing, this piece here is a plea for teaching formal methods. It's nicely written I admit, but it is also unbelievably smug and disconnected from reality. Even in physics or mathematics, which are obviously much more mathematically tractable than computer science, people do not do significant new things by using only formal methods. In fact, the technical achievement Dijkstra is most known for, Dijkstra's algorithm, was not invented using formal methods, but like most discoveries ever it occurred in a flash of insight after a long period of thinking, as he said in an interview. No matter how much one loves rigour, the dream of formalizing all reasoning has turned out to be a pipe-dream, as evidenced for example by the failure of the Hilbert program, and people everywhere proceed about their business as usual. Mathematics is not, after all, just the manipulation of a string of symbols, and neither is Computer Science, even if all computers do is exactly this, because we humans are complex beings, largely driven by emotions, not consciously aware of all the reasoning processes going on, that are often reasoning in "fuzzy" ways (and frequently with good effects), as opposed to being machines executing chains of logical inferences. In fact, people are born with very different internal worlds, some people are really good at symbol manipulation, algebra, and language, their daily thinking consists of "talking to themselves", while some people naturally think by imagining pictures and having various loose sensual impressions, among the latter for example the great mathematician Poincare. Was Poincare in need of someone to "really teach him mathematics"? Unfortunately I think Dijkstra assumed everyone is identical to him. Before preaching this too much, look at the practical implementations of his ideas on this, for example have a look at him lecturing on a technical topic: http://www.youtube.com/watch?v=qNCAFcAbSTg http://www.youtube.com/watch?v=qNCAFcAbSTg or read "A discipline of programming". As nice as the EWD prose is, I honestly can't stand the man talking about anything technical for more than 5 minutes. The more concrete the EWDs get the worse they are. For some perspective on how science really gets done, as opposed to people's romantic images of how it is done, I recommend "The Sleepwalkers" by Arthur Koestler, about the Copernican revolution, and "The psychology of mathematical invention" by Hadamard.

deleted 13y ago
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downer93 13y ago
But, however much you might bristle at his tone, he has something significant to say, and he's right when he says it. You can't take this paper (or any other) as an end-all/be-all statement isolated in a vacuum. Maybe his smug tone portends that he might presume as much, but it's a mistake to take it as a one-size-fits all remark. The thing he gets right is this: Teaching students "Computer Science" as a new discipline by showing them how to reverse engineer existing examples is a mistake. It's a mistake in the same sense that you don't teach math by giving students a number and asking them what the problem was. That's an absurd approach to math. 96. Okay, now give me the equation. That's the idea he's driving at. And in many ways he's right. Does that mean that reverse engineering is a completely invalid approach to learning? No. For some disciplines, it is essential, and indeed, for certain aspects of electrical engineering, which ulimately melds with programming, one needs those sorts of strategies ready at hand. But when it comes down to writing programs, he's cautioning that you should learn the task as a top-down approach, not by starting at the bottom, and then climbing up through someone else's ready-made tangle of spaghetti. Does reverse engineering work for medicine and biology, or even chemistry? Well, what the hell kind of a choice did we have? Humanity had to bootstrap out of hunter/gatherer mode one way or another, but it doesn't mean we have to approach computer science the same way, and in fact, there's no rational reason to do so. Read deeply enough into this message, and you'll unravel the mystery of why open source development is beneficial and generous, and proprietary closed source products really do represent a malign animosity toward the end user, by only providing the bald number as the result, and never teaching the man to fish. But hey, there's that old refrain: we all gotta eat right, so how do we make money when we're giving everything away and not rationing a portion for yourself? Dijkstra comes from the era when computer scientists were a priesthood, moreso than tradesman. Computer science was esoteric, and so there was no fear of "teaching a slave to read" because there really weren't enough books to go around. Computers were high holy temples of time sharing cloistered atop the ivory tower. But in his message here, you'll gain insight into the fundamental truth, that when there are billions of cycles per second, acting on trillions of bytes at a time, there's no hope of brute force reverse engineering the resulting output of the system as a post mortem. Sometimes that's what we're stuck with, but it's not the ideal, and it's an impractical approach, not unlike picking up the pieces of an air disaster on a mountain top. Code needs to be well organized and properly conceived from the outset, and this is the desired approach, and a fundamental principle new students should have beaten into them, mercilessly.

by stiff 13y ago

deleted 13y ago

[deleted]

downer93 13y ago

But, however much you might bristle at his tone, he has something significant to say, and he's right when he says it. You can't take this paper (or any other) as an end-all/be-all statement isolated in a vacuum. Maybe his smug tone portends that he might presume as much, but it's a mistake to take it as a one-size-fits all remark. The thing he gets right is this: Teaching students "Computer Science" as a new discipline by showing them how to reverse engineer existing examples is a mistake. It's a mistake in the same sense that you don't teach math by giving students a number and asking them what the problem was. That's an absurd approach to math. 96. Okay, now give me the equation. That's the idea he's driving at. And in many ways he's right. Does that mean that reverse engineering is a completely invalid approach to learning? No. For some disciplines, it is essential, and indeed, for certain aspects of electrical engineering, which ulimately melds with programming, one needs those sorts of strategies ready at hand. But when it comes down to writing programs, he's cautioning that you should learn the task as a top-down approach, not by starting at the bottom, and then climbing up through someone else's ready-made tangle of spaghetti. Does reverse engineering work for medicine and biology, or even chemistry? Well, what the hell kind of a choice did we have? Humanity had to bootstrap out of hunter/gatherer mode one way or another, but it doesn't mean we have to approach computer science the same way, and in fact, there's no rational reason to do so. Read deeply enough into this message, and you'll unravel the mystery of why open source development is beneficial and generous, and proprietary closed source products really do represent a malign animosity toward the end user, by only providing the bald number as the result, and never teaching the man to fish. But hey, there's that old refrain: we all gotta eat right, so how do we make money when we're giving everything away and not rationing a portion for yourself? Dijkstra comes from the era when computer scientists were a priesthood, moreso than tradesman. Computer science was esoteric, and so there was no fear of "teaching a slave to read" because there really weren't enough books to go around. Computers were high holy temples of time sharing cloistered atop the ivory tower. But in his message here, you'll gain insight into the fundamental truth, that when there are billions of cycles per second, acting on trillions of bytes at a time, there's no hope of brute force reverse engineering the resulting output of the system as a post mortem. Sometimes that's what we're stuck with, but it's not the ideal, and it's an impractical approach, not unlike picking up the pieces of an air disaster on a mountain top. Code needs to be well organized and properly conceived from the outset, and this is the desired approach, and a fundamental principle new students should have beaten into them, mercilessly.