Why is everyone in such a rush?
Walk into any bookstore, and you'll see how to Teach Yourself Javain 24 Hours alongside endless variations offering to teach C,SQL, Ruby, Algorithms, and so on in a few days or hours. The Amazon advanced search for [title: teach,yourself, hours, since: 2000 and found 512 such books. Of the top ten, nine are programming books (the other is about bookkeeping). Similar results come from replacing "teach yourself" with "learn" or "hours" with "days."The conclusion is that either people are in a big rush to learnabout programming, or that programming is somehow fabulously easier tolearn than anything else. Felleisen et al.give a nod to this trend in their book How to Design Programs, when they say"Bad programming is easy. Idiots can learn it in 21 days,even if they are dummies." The Abtruse Goose comic also had their take.
Let's analyze what a title like Teach Yourself C++ in 24 Hourscould mean:
- Teach Yourself: In 24 hours 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.
- C++: In 24 hours 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 Processing) 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.
- in 24 Hours: Unfortunately, this is not enough, as the nextsection shows.
Teach Yourself Programming in Ten Years
Researchers (Bloom(1985), , Hayes(1989), ) 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 deliberativepractice: 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, Sgt. Peppers, was released in 1967.MalcolmGladwell has popularized the idea, although he concentrates on 10,000 hours, not 10 years.Henri Cartier-Bresson (1908-2004) had another metric: "Your first 10,000 photographs are your worst." (He didn'tanticipate that with digital cameras, some people can reach that mark in a week.)True expertise may take a lifetime:Samuel Johnson (1709-1784) said "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." Of course, no single number can be the final answer: it doesn't seem reasonableto assume that all skills (e.g., programming, chess playing, checkers playing, and music playing)could all require exactly the same amount of time to master, nor that all peoplewill take exactly the same amount of time. As Prof. K. Anders Ericsson puts it, "In most domains it's remarkable how much time even the mosttalented individuals need in order to reach the highest levels of performance. The 10,000 hour number just gives you a sense that we're talking years of 10 to 20 hours a week which those who some people would argue are the most innately talented individuals still need to get to the highest level."
So You Want to be a Programmer
Here's my recipe for programming success:
- Get interested in programming, and do some because it is fun. Make surethat it keeps being enough fun so that you will be willing to put in your ten years/10,000 hours.
- Program. The best kind of learning is learningby doing. To put it more technically, "the maximal level ofperformance for individuals in a given domain is not attainedautomatically as a function of extended experience, but the level ofperformance can be increased even by highly experienced individuals asa result of deliberate efforts to improve." (p. 366)and "the most effective learning requires a well-defined task with anappropriate difficulty level for the particular individual,informative feedback, and opportunities for repetition and correctionsof errors." (p. 20-21) The book Cognition in Practice: Mind, Mathematics, and Culture in EverydayLife is an interesting reference for this viewpoint.
- Talk with other programmers; read other programs. This is more importantthan any book or training course.
- If you want, put in four years at a college (or more at agraduate school). This will give you access to some jobs that requirecredentials, and it will give you a deeper understanding of the field,but if you don't enjoy school, you can (with some dedication) getsimilar experience on your own or on the job. In any case, book learning alone won'tbe enough. "Computer science education cannot make anybody an expertprogrammer any more than studying brushes and pigment can makesomebody an expert painter" says Eric Raymond, author of The NewHacker's Dictionary. One of the best programmers I ever hired hadonly a High School degree; he's produced a lot of great software, has his own news group, and made enough in stock options to buy his own nightclub.
- Work on projects with other programmers. Be the best programmeron some projects; be the worst on some others. When you're the best,you get to test your abilities to lead a project, and to inspireothers with your vision. When you're the worst, you learn what themasters do, and you learn what they don't like to do (because theymake you do it for them).
- Work on projects after other programmers. Understand a program written by someone else. See what it takes tounderstand and fix it when the original programmers are notaround. Think about how to design your programs to make it easier forthose who will maintain them after you.
- Learn at least a half dozen programming languages. Include onelanguage that emphasizes class abstractions (like Java or C++), one thatemphasizes functional abstraction (like Lisp or ML or Haskell), onethat supports syntactic abstraction (like Lisp), onethat supports declarative specifications (like Prolog or C++templates), andone that emphasizes parallelism (like Clojure or Go).
- Remember that there is a "computer" in "computer science". Knowhow long it takes your computer to execute an instruction, fetch aword from memory (with and without a cache miss), read consecutive words from disk, and seek to a new location on disk. (Answers here.)
- Get involved in a languagestandardization effort. It could be the ANSI C++ committee, or itcould be deciding if your local coding style will have 2 or 4 spaceindentation levels. Either way, you learn about what other peoplelike in a language, how deeply they feel so, and perhaps even a littleabout why they feel so.
- Have the good sense to get off the language standardization effort asquickly as possible.
Fred Brooks, in his essay No Silver Bullet identified a three-part plan for finding greatsoftware designers:
- Systematically identify top designers as early as possible.
- Assign a career mentor to be responsible for the development of the prospect and carefully keep a career file.
- Provide opportunities for growing designers to interact and stimulate each other.
So go ahead and buy that Java/Ruby/Javascript/PHP book; you'llprobably get some use out of it. But you won't change your life, oryour real overall expertise as a programmer in 24 hours or 21 days. How about working hard to continually improve over 24 months?Well, now you're starting to get somewhere...
References
Bloom, Benjamin (ed.) Developing Talent in Young People, Ballantine, 1985.
Brooks, Fred, No Silver Bullets, IEEE Computer, vol. 20, no. 4, 1987, p. 10-19.
Hayes, John R., Complete Problem Solver Lawrence Erlbaum, 1989.
Chase, William G. & Simon, Herbert A. "Perception in Chess"Cognitive Psychology, 1973, 4, 55-81.
Lave, Jean, Cognition in Practice: Mind, Mathematics, and Culture in EverydayLife, Cambridge University Press, 1988.
Answers
Approximate timing for various operations on a typical PC:execute typical instruction | 1/1,000,000,000 sec = 1 nanosec |
fetch from L1 cache memory | 0.5 nanosec |
branch misprediction | 5 nanosec |
fetch from L2 cache memory | 7 nanosec |
Mutex lock/unlock | 25 nanosec |
fetch from main memory | 100 nanosec |
send 2K bytes over 1Gbps network | 20,000 nanosec |
read 1MB sequentially from memory | 250,000 nanosec |
fetch from new disk location (seek) | 8,000,000 nanosec |
read 1MB sequentially from disk | 20,000,000 nanosec |
send packet US to Europe and back | 150 milliseconds = 150,000,000 nanosec |
Appendix: Language Choice
Several people have asked what programming language they should learn first.There is no one answer, but consider these points:- Use your friends. When asked "what operating system shouldI use, Windows, Unix, or Mac?", my answer is usually: "use whateveryour friends use." The advantage you get from learning from yourfriends will offset any intrinsic difference between OS, orbetween programming languages. Also consider your future friends:the community of programmers that you will be a part of if youcontinue. Does your chosen language have a large growing communityor a small dying one? Are there books, web sites, and online forumsto get answers from? Do you like the people in those forums?
- Keep it simple. Programming languages such as C++and Java are designed for professional development by large teams ofexperienced programmers who are concerned about the run-time efficiency oftheir code.As a result, these languages have complicated parts designed for these circumstances.You're concerned with learning to program. You don't need that complication.You want a language that was designed to be easy to learn and remember by asingle new programmer.
- Play. Which way would you rather learn to play the piano: thenormal, interactive way, in which you hear each note as soon as you hit a key,or "batch" mode, in which you only hear the notes after you finish a whole song?Clearly, interactive mode makes learning easier for the piano, and also for programming. Insist on a language with an interactive mode and use it.
Appendix: Books and Other Resources
Several people have asked what books and web pages they should learnfrom. I repeat that "book learning alone won't be enough" but I canrecommend the following:- Scheme: Structure andInterpretation of Computer Programs (Abelson & Sussman) isprobably the best introduction to computer science, and it doesteach programming as a way of understanding the computer science. You can see online videos of lectures on this book, as well as the complete text online. The book ischallenging and will weed out some people who perhaps could besuccessful with another approach.
- Scheme:How toDesign Programs (Felleisen et al.) is one of the best bookson how to actually design programs in an elegant and functional way.
- Python: Python Programming:An Intro to CS (Zelle) is a good introduction using Python.
- Python: Severalonline tutorials are available at Python.org.
- Oz: Concepts,Techniques, and Models of Computer Programming (Van Roy & Haridi)is seen by some as the modern-day successor to Abelson & Sussman.It is a tour through the big ideas of programming, covering a widerrange than Abelson & Sussman while being perhaps easier to read andfollow. It uses a language, Oz, that is not widely known but serves asa basis for learning other languages.<
Notes
T. Capey points out that the Complete Problem Solver page on Amazon now has the "Teach Yourself Bengali in 21 days" and "Teach Yourself Grammar and Style" books under the "Customers who shopped for this item also shopped for these items" section. I guess that a large portion of the people who look at that book are coming from this page.Thanks to Ross Cohen for help with Hippocrates.Translations
Thanks to thefollowing authors,translations of this page areavailable in:Arabic(Mohamed A. Yahya)

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