Teach yourself programing in ten years. - 软件编程/OS - 电子工程师俱

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Teach Yourself Programming in Ten YearsPeter NorvigWhy is everyone in such a rush?Walk into any bookstore, and you'll see how to <i>Teach Yourself Javain 7 Days</i> alongside endless variations offering to teach VisualBasic, Windows, the Internet, and so on in a few days or hours.I didthe following power search at Amazon.com:  pubdate: after 1992 and title: days and
  (title: learn or title: teach yourself)and got back 248 hits.The first 78 were computer books (number 79was <i>LearnBengali in 30 days</i>).I replaced "days" with "hours"and got remarkably similar results: 253 more books, with 77 computerbooks followed by <i>TeachYourself Grammar and Style in 24 Hours</i> at number 78. Out ofthe top 200 total, 96% were computer books.The conclusion is that either people are in a big rush to learnabout computers, or that computers are somehow fabulously easier tolearn than anything else.There are no books on how to learnBeethoven, or Quantum Physics, or even Dog Grooming in a few days.Felleisen <i>et al.</i>give a nod to this trend in their book <i>How to Design Programs</i>, when they say"Bad programming is easy. <i>Idiots</i> can learn it in <i>21 days</i>,even if they are <i>dummies</i>.
Let's analyze what a title like <i>Learn C++ in Three Days</i>could mean:
<ul><li><strong>Learn:</strong> In 3 days you won't have time to write severalsignificant programs, and learn from your successes and failures withthem.You won't have time to work with an experienced programmer andunderstand what it is like to live in a C++ environment.In short, youwon't have time to learn much.So the book can only be talking about asuperficial familiarity, not a deep understanding. As Alexander Pope said,a little learning is a dangerous thing.<li><strong>C++:</strong> In 3 days you might be able to learn some of the syntax ofC++ (if you already know another language), but you couldn'tlearn much about how to use the language.In short, if you were, say, aBasic programmer, you could learn to write programs in the style ofBasic using C++ syntax, but you couldn't learn what C++ isactually good (and bad) for.So what's the point?AlanPerlis once said: "A language that doesn't affect the way youthink about programming, is not worth knowing".One possible point isthat you have to learn a tiny bit of C++ (or more likely, somethinglike JavaScript or Flash's Flex) because you need to interface with anexisting tool to accomplish a specific task. But then you're notlearning how to program; you're learning to accomplish that task.<li><strong>in Three Days:</strong> Unfortunately, this is not enough, as the nextsection shows.</ul>Teach Yourself Programming in Ten YearsResearchers (Bloom(1985), Bryan & Harter (1899), Hayes(1989), Simmon & Chase (1973)) have shown ittakes about ten years to develop expertise in any of a wide variety ofareas, including chess playing, music composition, telegraphoperation, painting, piano playing, swimming, tennis, and research inneuropsychology and topology.The key is <i>deliberative</i>practice: not just doing it again and again, but challenging yourselfwith a task that is just beyond your current ability, trying it,analyzing your performance while and after doing it, and correctingany mistakes.Then repeat.And repeat again.There appear to be noreal shortcuts: even Mozart, who was a musical prodigy at age 4, took13 more years before he began to produce world-class music.Inanother genre, the Beatles seemed to burst onto the scene with astring of #1 hits and an appearance on the Ed Sullivan show in 1964.But they had been playing small clubs in Liverpool and Hamburg since1957, and while they had mass appeal early on, their first greatcritical success, <i>Sgt. Peppers</i>, was released in 1967. MalcolmGladwell reports that a study of students at the Berlin Academy ofMusic compared the top, middle, and bottom third of the class andasked them how much they had practiced:<blockquote>Everyone, from all three groups, started playing at roughly the sametime - around the age of five. In those first few years, everyonepractised roughly the same amount - about two or three hours aweek. But around the age of eight real differences started toemerge. The students who would end up as the best in their class beganto practise more than everyone else: six hours a week by age nine,eight by age 12, 16 a week by age 14, and up and up, until by the ageof 20 they were practising well over 30 hours a week. By the age of20, the elite performers had all totalled 10,000 hours of practiceover the course of their lives. The merely good students had totalled,by contrast, 8,000 hours, and the future music teachers just over4,000 hours.</blockquote>So it may be that 10,000 hours, not 10 years, is the magic number.Samuel Johnson (1709-1784) thought ittook longer: "Excellence in any department can beattained only by the labor of a lifetime; it is not to be purchased ata lesser price."And Chaucer (1340-1400) complained "the lyf so short, the craftso long to lerne." Hippocrates (c. 400BC) is known for the excerpt "ars longa,vita brevis", which is part of the longer quotation "Ars longa, vitabrevis, occasio praeceps, experimentum periculosum, iudiciumdifficile", which in English renders as "Life is short, [the] craftlong, opportunity fleeting, experiment treacherous, judgmentdifficult."Although in Latin, <i>ars</i> can mean either art orcraft, in the original Greek the word "techne" can only mean "skill", not "art".