12 ms·

Khan Academy Triples Unique Users To 3.5 Million

96 points by ssclafani 15y ago

rubergly 15y ago
In case anyone is wondering, Khan Academy did not launch today, as CrunchBase seems to think.
michaelchisari 15y ago
Count me as one of those recent sign-ups. I've been doing Khan Academy religiously for the past month, and have gotten up to 800,000 points and 185/211 exercises. The practice board is addicting and fun, and reminds me in ways of role playing games (like Final Fantasy XI's "License Board"), which I've always been a fan of. After I finish, I plan on moving on to the MIT OCW math classes. I can't imagine how much easier K-12 would have been had Khan Academy been around. I've looked at other math and learning resources, and while they're all solid in ways, there just seems to be something that Khan "gets" that others don't, even if it's just as simple as a good UI and design. In my opinion, Khan Academy is worth every ounce of hype, and I'm usually someone who is strongly anti-hype.
- mrchess 15y ago
  This is gonna sound stupid but I'm serious. Did you learn anything worthwhile from your investment? Any new useful "skill" or all just top level knowledge? Do you consider materials learned from Khan life changing?
  - 0x12 15y ago
    Why would it have to be life changing in order to be useful? The trade-off could well be watching soaps vs re-doing your high school or university level math.
    - mrchess 15y ago
      I meant useful or lifechanging as two seperate questions -- no correlation.
  - pyoung 15y ago
    One could argue the same thing about a traditional college degree. You spend a ton of money, take four years out of your life, and are forced to take a bunch of classes that don't even pertain to your major (breadth requirements). At least with Khan, it is free, it can be done in your spare time, and you only focus on things that actually interest you.
sosuke 15y ago
I'm loving Khan Academy since I saw a post by John Resig about their practice framework. Math is so much more fun and interesting since I started using Khan Academy.
- kiba 15y ago
  Unless you practice your mathematics and physics daily, you will eventually forget most of what you know.
  - gwern 15y ago
    Yes, but hopefully KA will get its spaced repetition ( http://www.gwern.net/Spaced%20repetition http://www.gwern.net/Spaced%20repetition ) efforts going at some point, while most users are still there.
  - sosuke 15y ago
    Whenever you login they put refreshers of previous exercises at the top which I love. I know if I don't use it I'll lose it but it has been a lot of fun learning there.
0x12 15y ago
I love the Khan academy, it is one of the best things that came out of the internet to date. But I really wished that they would allow me to sign up with them and them alone without having to use either google or facebook to log in, that's a really bad mistake on their part imo.
- tptacek 15y ago
  Why? Things seem to be going well for them (look at the article you're commenting on). There are smart web people building this system up; presumably this is something they thought hard about before implementing.
  - 0x12 15y ago
    - facebook and/or google may not be around forever - my account with facebook and/or google could get disabled by them on a whim, severing my link with the Khan academy - there is no upside to me to log in with a facebook and/or google account - there is a downside, which is that I have to sign up for a different service, that I may have valid reasons for not wanting to join (in the case of fb that does not require a whole lot of imagination) And so on. Really, when you only allow people to log in to your site by forcing them to become a member of another site first you are creating a barrier that need not exist. I'm sure there are plenty of valid reasons for them why they do it this way (possibly, for instance because google and facebook do a lot of work to ensure that their accounts are only given out to those that deserve it, thereby cutting out on spam), but for me it does not work. For sure that is a small minorities, but small minorities are at least still allowed to speak up. Good thing HN does not require a facebook or a google login.
    - genieyclo 15y ago
      - the likelihood of Facebook or Google disappearing anytime soon is very minimal - the stories of disabled accounts are vastly over-hyped, and the likelihood of it happening are almost nil - there is significant upside for you to use your Facebook or Google account to signup/login with a service. Much less work, it's one click to login after you authorize it every time, no need to have another login/pass combo, and if you wish to no longer use the site, it's easy to disable - most people have a Facebook or Google already, especially KA's market The effort to create and maintain signups/logins separately for KA vs using existing drop-in solutions for both Google & FB makes the decision obvious. This is a much more convenient solution for both the users and devs of KA. HN does not require but does allow you to use a similiar login scheme with Clickpass.
graeme 15y ago
I teach the SAT, and I have all of my students do the arithmetic exercises on Khan academy + the exercises for any subjects they have difficulty with. It works great. Students nowadays tend to do all of their math on a calculator; they're not so great at mental math. It really holds them back on the SAT. The test's format invites calculation errors. The SAT specific videos are great, too.
gghootch 15y ago
1. I wonder what their international user base looks like. (Not counting native English speaking countries like UK & India) Two weeks ago my mom cut out a lengthy article for me, as she often does when she thinks she's read something relevant to my interests. To my surprise it was on Khan Academy, something I already read about past summer in Wired. 2. Does anyone know whether KA has received any more international press coverage lately?
- bantic 15y ago
  KA plus One Laptop per Child would be an incredibly powerful combination for third-world schools. OLPC should make it the homepage on the XO.
hugh3 15y ago
I hadn't looked at Khan Academy in a year or so, but it looks like they've vastly expanded their offerings since then. In particular, they've added a couple of hundred lessons of Art History stuff, which I'm quite keen to look through. The mathematics and physics stuff would have been great for me... if it had existed fifteen years ago.
nickik 15y ago
I think it would be nice if MIT (and others) would make a deal with the khanacadamy to provide there courses in a khanvideo style and change there exercises in khan-style exercises. Everbody on the World should be able to learn anything from 1+1 to quantum physics on khanacadamy. OCW kind of stuff is already super awesome but in would be much better in a khan-style. When you watch lectures on OCW you know its not for you, its for the studens in the class. The professor talks about when the exams are and so on. The other thing is that its hard to know when you are ready to take a course, in the khan system you could show what you have to know to do the course. I see a bright future for education.
- ahmadss 15y ago
  1 - Sal Khan was at one point on the OCW Board. The possibility of OCW borrowing/partnering/licensing KA's dashboard, interface, knowledge map, and the like is not outside the realm of possibility BUT... 2 - ...it won't happen anytime soon because the funding/grants KA received from Gates Foundation and Google Grants is primarily for internationalization of the app and translation of the videos. 3 - I'd welcome OCW improving their interface, so if any MIT CS students are reading this, you all might want to volunteer time to improve the OCW app.
- tokenadult 15y ago
  change there exercises in khan-style exercises It would be a disaster for MIT's education if the legendary MIT problem sets were turned into Khan Academy-style exercises. To explain why I think so, allow me to quote the FAQ I prepare about the distinction between "problems" and "exercises" in mathematics instruction for families of students in the math classes I teach: PROBLEMS VERSUS EXERCISES I frequently encounter discussions among parents about repetitive school math lessons, so a few years ago I prepared this Frequently Asked Question (FAQ) document about the distinction between math exercises (good in sufficient but not excessive amount) and math problems (always good in any amount). Most books about mathematics have what are called "exercises" in them, questions that prompt a learner to practice the concepts discussed in the mathematics book. By reading one mathematics book, and then several more, I learned that some mathematicians draw a distinction between "exercises" and "problems" (which is the terminology generally used by the mathematicians who draw this distinction). I think this distinction is useful for teachers and learners to consider while selecting materials for studying mathematics, so I'll share the quotations from which I learned this distinction here. I first read about the distinction between exercises and problems in a Taiwan reprint of a book by Howard Eves. "It is perhaps pertinent to make a comment or two here about the problems of the text. There is a distinction between what may be called a PROBLEM and what may be considered an EXERCISE. The latter serves to drill a student in some technique or procedure, and requires little, if any, original thought. Thus, after a student beginning algebra has encountered the quadratic formula, he should undoubtedly be given a set of exercises in the form of specific quadratic equations to be solved by the newly acquired tool. The working of these exercises will help clinch his grasp of the formula and will assure his ability to use the formula. An exercise, then, can always be done with reasonable dispatch and with a minimum of creative thinking. In contrast to an exercise, a problem, if it is a good one for its level, should require thought on the part of the student. The student must devise strategic attacks, some of which may fail, others of which may partially or completely carry him through. He may need to look up some procedure or some associated material in texts, so that he can push his plan through. Having successfully solved a problem, the student should consider it to see if he can devise a different and perhaps better solution. He should look for further deductions, generalizations, applications, and allied results. In short, he should live with the thing for a time, and examine it carefully in all lights. To be suitable, a problem must be such that the student cannot solve it immediately. One does not complain about a problem being too difficult, but rather too easy. "It is impossible to overstate the importance of problems in mathematics. It is by means of problems that mathematics develops and actually lifts itself by its own bootstraps. Every research article, every doctoral thesis, every new discovery in mathematics, results from an attempt to solve some problem. The posing of appropriate problems, then, appears to be a very suitable way to introduce the student to mathematical research. And it is worth noting, the more problems one plays with, the more problems one may be able to pose on one's own. The ability to propose significant problems is one requirement to be a creative mathematician." Eves, Howard (1963). A Survey of Geometry volume 1. Boston: Allyn and Bacon, page ix. I have since read about this distinction in several other books. "Before going any further, let's digress a minute to discuss different levels of problems that might appear in a book about mathematics: Level 1. Given an explicit object x and an explicit property P(x), prove that P(x) is true. . . . Level 2. Given an explicit set X and an explicit property P(x), prove that P(x) is true for FOR ALL x [existing in] X. . . . Level 3. Given an explicit set X and an explicit property P(x), prove OR DISPROVE that P(x) is true for for all x [existing in] X. . . . Level 4. Given an explicit set X and an explicit property P(x), find a NECESSARY AND SUFFICIENT CONDITION Q(x) that P(x) is true. . . . Level 5. Given an explicit set X, find an INTERESTING PROPERTY P(x) of its elements. Now we're in the scary domain of pure research, where students might think that total chaos reigns. This is real mathematics. Authors of textbooks rarely dare to pose level 5 problems." Graham, Ronald, Knuth, Donald, and Patashnik, Oren (1994). Concrete Mathematics Second Edition. Boston: Addison-Wesley, pages 72-73. This digression becomes the subject of a, um, problem in Exercise 4 of Chapter 3: "The text describes problems at levels 1 through 5. What is a level 0 problem? (This, by the way, is NOT a level 0 problem.)" "First, what is a PROBLEM? We distinguish between PROBLEMS and EXERCISES. An exercise is a question that you know how to resolve immediately. Whether you get it right or not depends on how expertly you apply specific techniques, but you don't need to puzzle out what techniques to use. In contrast, a problem demands much thought and resourcefulness before the right approach is found. . . . "A good problem is mysterious and interesting. It is mysterious, because at first you don't know how to solve it. If it is not interesting, you won't think about it much. If it is interesting, though, you will want to put a lot of time and effort into understanding it." Zeitz, Paul (1999). The Art and Craft of Problem Solving. New York: Wiley, pages 3 and 4. ". . . . As Paul Halmos said, 'Problems are the heart of mathematics,' so we should 'emphasize them more and more in the classroom, in seminars, and in the books and articles we write, to train our students to be better problem-posers and problem-solvers than we are.' "The problems we have selected are definitely not exercises. Our definition of an exercise is that you look at it and know immediately how to complete it. It is just a question of doing the work, whereas by a problem, we mean a more intricate question for which at first one has probably no clue to how to approach it, but by perseverance and inspired effort one can transform it into a sequence of exercises." Andreescu, Titu & Gelca, Razvan (2000), Mathematical Olympiad Challenges. Boston: Birkhäuser, page xiii. "It is easier to advance in one topic by going ahead with the more elementary parts of another topic, where the first one is applied. The brain much prefers to work that way, rather than to concentrate on ugly technical formulas which are obviously unrelated to anything except artificial drilling. Of course, some rote drilling is necessary. The problem is how to strike a balance." Lang, Serge (1988), Basic Mathematics. New York: Springer-Verlag, p. xi. "Learn by Solving Problems "We believe that the best way to learn mathematics is by solving problems. Lots and lots of problems. In fact, we believe the best way to learn mathematics is to try to solve problems that you don't know how to do. When you discover something on your own, you'll understand it much better than if someone just tells it to you. . . . . "If you find the problems are too easy, this means you should try harder problems. Nobody learns very much by solving problems that are too easy for them." Rusczyk, Richard (2007). Introduction to Algebra. Alpine, CA: AoPS Incorporated, p. iii.
vasco 15y ago
Isn't it required to be at least 13 years old to have a google account? How does this affect the kids who want to use khanacademy? Are they forced to have a facebook account? EDIT: Actually, facebook also has a minimum age requirement of 13 (https://www.facebook.com/help/?faq=210644045634222 https://www.facebook.com/help/?faq=210644045634222). Can't see how khanacademy missed that. I think this is a major flaw in their signup system. Should they (khanacademy) really be blocking every kid younger then 13? EDIT2: It seems like they address it here (http://www.khanacademy.org/about/getting-started http://www.khanacademy.org/about/getting-started) but their solution is having the parents create an account for the kids. I don't really think this is actually acceptable by facebook's terms of service though, not sure about google. See point 4 in https://www.facebook.com/terms.php https://www.facebook.com/terms.php
- corysama 15y ago
  From http://www.khanacademy.org/about/getting-started http://www.khanacademy.org/about/getting-started ----------------------- If your students are under 13: You currently have two options: you can sign your school up for Google Apps for Education, which will help you provide each student with a Google account that can be used with Khan Academy, or you can have your students' parents individually create accounts for each student on either Google or Facebook. We are constantly working to improve this situation, but that's the best we've got at the moment (sorry!). If you already have Google Apps for Education accounts but aren't able to use them to sign in on the Khan Academy, you might need to upgrade your account.
  - vasco 15y ago
    That's only for people with Google Apps for Education (teachers)!! Also, if you are under 13 you can't use the site if you didn't sign up with google/facebook (which have their own weird under 13 rules) See "1. Eligibility" in (http://www.khanacademy.org/about/tos http://www.khanacademy.org/about/tos) EDIT: Also, I found out that youtube actually doesn't let anyone under 13 use their service, so I'm guessing you can't watch the videos either if you're under 13. See "12. Ability to Accept Terms of Service" in (http://www.youtube.com/static?gl=US&template=terms http://www.youtube.com/static?gl=US&template=terms) I just found out the internet is just for people over 13...
pixcavator 15y ago
I'd be much more impressed it these (or at least a part of them) were paying customers.
- solutionyogi 15y ago
  Why? Khan Academy is a non profit organization. They are not looking to make money. They are trying to change the world of education. I am impressed by these numbers because it means that more people are now aware that there is a quality free resource where they can educate themselves.
  - pixcavator 15y ago
    Why would it be more impressive? Because paying customers vote with their money. Money is a better validation than "you're great!".
    - solutionyogi 15y ago
      Yes, money is a validation if your goal is to make money. If I am a for-profit company and I show you millions of visitors for my website but no real revenues, I would agree that it's not impressive. As the other commentator pointed out, their goal is not to make money. And this is impressive because it's a huge progress towards their stated goal.
- corysama 15y ago
  "We're a not-for-profit with the goal of changing education for the better by providing a free world-class education to anyone anywhere." http://www.khanacademy.org/about http://www.khanacademy.org/about
  - pixcavator 15y ago
    Non profit != no charge
    - 15y ago
dbbo 15y ago
I found some of Khan's orgo videos helpful review material. In fact, the doctorate-level professor I had didn't do a much better job (if at all better) of explaining the material the first time around.

96 points by ssclafani 15y ago

In case anyone is wondering, Khan Academy did not launch today, as CrunchBase seems to think.

Count me as one of those recent sign-ups. I've been doing Khan Academy religiously for the past month, and have gotten up to 800,000 points and 185/211 exercises. The practice board is addicting and fun, and reminds me in ways of role playing games (like Final Fantasy XI's "License Board"), which I've always been a fan of. After I finish, I plan on moving on to the MIT OCW math classes. I can't imagine how much easier K-12 would have been had Khan Academy been around. I've looked at other math and learning resources, and while they're all solid in ways, there just seems to be something that Khan "gets" that others don't, even if it's just as simple as a good UI and design. In my opinion, Khan Academy is worth every ounce of hype, and I'm usually someone who is strongly anti-hype.

mrchess 15y ago
This is gonna sound stupid but I'm serious. Did you learn anything worthwhile from your investment? Any new useful "skill" or all just top level knowledge? Do you consider materials learned from Khan life changing?
- 0x12 15y ago
  Why would it have to be life changing in order to be useful? The trade-off could well be watching soaps vs re-doing your high school or university level math.
  - mrchess 15y ago
    I meant useful or lifechanging as two seperate questions -- no correlation.
- pyoung 15y ago
  One could argue the same thing about a traditional college degree. You spend a ton of money, take four years out of your life, and are forced to take a bunch of classes that don't even pertain to your major (breadth requirements). At least with Khan, it is free, it can be done in your spare time, and you only focus on things that actually interest you.

sosuke 15y ago

I'm loving Khan Academy since I saw a post by John Resig about their practice framework. Math is so much more fun and interesting since I started using Khan Academy.

kiba 15y ago
Unless you practice your mathematics and physics daily, you will eventually forget most of what you know.
- gwern 15y ago
  Yes, but hopefully KA will get its spaced repetition ( http://www.gwern.net/Spaced%20repetition http://www.gwern.net/Spaced%20repetition ) efforts going at some point, while most users are still there.
- sosuke 15y ago
  Whenever you login they put refreshers of previous exercises at the top which I love. I know if I don't use it I'll lose it but it has been a lot of fun learning there.

0x12 15y ago

I love the Khan academy, it is one of the best things that came out of the internet to date. But I really wished that they would allow me to sign up with them and them alone without having to use either google or facebook to log in, that's a really bad mistake on their part imo.

tptacek 15y ago
Why? Things seem to be going well for them (look at the article you're commenting on). There are smart web people building this system up; presumably this is something they thought hard about before implementing.
- 0x12 15y ago
  - facebook and/or google may not be around forever - my account with facebook and/or google could get disabled by them on a whim, severing my link with the Khan academy - there is no upside to me to log in with a facebook and/or google account - there is a downside, which is that I have to sign up for a different service, that I may have valid reasons for not wanting to join (in the case of fb that does not require a whole lot of imagination) And so on. Really, when you only allow people to log in to your site by forcing them to become a member of another site first you are creating a barrier that need not exist. I'm sure there are plenty of valid reasons for them why they do it this way (possibly, for instance because google and facebook do a lot of work to ensure that their accounts are only given out to those that deserve it, thereby cutting out on spam), but for me it does not work. For sure that is a small minorities, but small minorities are at least still allowed to speak up. Good thing HN does not require a facebook or a google login.
  - genieyclo 15y ago
    - the likelihood of Facebook or Google disappearing anytime soon is very minimal - the stories of disabled accounts are vastly over-hyped, and the likelihood of it happening are almost nil - there is significant upside for you to use your Facebook or Google account to signup/login with a service. Much less work, it's one click to login after you authorize it every time, no need to have another login/pass combo, and if you wish to no longer use the site, it's easy to disable - most people have a Facebook or Google already, especially KA's market The effort to create and maintain signups/logins separately for KA vs using existing drop-in solutions for both Google & FB makes the decision obvious. This is a much more convenient solution for both the users and devs of KA. HN does not require but does allow you to use a similiar login scheme with Clickpass.

graeme 15y ago

I teach the SAT, and I have all of my students do the arithmetic exercises on Khan academy + the exercises for any subjects they have difficulty with. It works great. Students nowadays tend to do all of their math on a calculator; they're not so great at mental math. It really holds them back on the SAT. The test's format invites calculation errors. The SAT specific videos are great, too.

gghootch 15y ago

1. I wonder what their international user base looks like. (Not counting native English speaking countries like UK & India) Two weeks ago my mom cut out a lengthy article for me, as she often does when she thinks she's read something relevant to my interests. To my surprise it was on Khan Academy, something I already read about past summer in Wired. 2. Does anyone know whether KA has received any more international press coverage lately?

bantic 15y ago
KA plus One Laptop per Child would be an incredibly powerful combination for third-world schools. OLPC should make it the homepage on the XO.

hugh3 15y ago

I hadn't looked at Khan Academy in a year or so, but it looks like they've vastly expanded their offerings since then. In particular, they've added a couple of hundred lessons of Art History stuff, which I'm quite keen to look through. The mathematics and physics stuff would have been great for me... if it had existed fifteen years ago.

nickik 15y ago

I think it would be nice if MIT (and others) would make a deal with the khanacadamy to provide there courses in a khanvideo style and change there exercises in khan-style exercises. Everbody on the World should be able to learn anything from 1+1 to quantum physics on khanacadamy. OCW kind of stuff is already super awesome but in would be much better in a khan-style. When you watch lectures on OCW you know its not for you, its for the studens in the class. The professor talks about when the exams are and so on. The other thing is that its hard to know when you are ready to take a course, in the khan system you could show what you have to know to do the course. I see a bright future for education.

ahmadss 15y ago
1 - Sal Khan was at one point on the OCW Board. The possibility of OCW borrowing/partnering/licensing KA's dashboard, interface, knowledge map, and the like is not outside the realm of possibility BUT... 2 - ...it won't happen anytime soon because the funding/grants KA received from Gates Foundation and Google Grants is primarily for internationalization of the app and translation of the videos. 3 - I'd welcome OCW improving their interface, so if any MIT CS students are reading this, you all might want to volunteer time to improve the OCW app.
tokenadult 15y ago
change there exercises in khan-style exercises It would be a disaster for MIT's education if the legendary MIT problem sets were turned into Khan Academy-style exercises. To explain why I think so, allow me to quote the FAQ I prepare about the distinction between "problems" and "exercises" in mathematics instruction for families of students in the math classes I teach: PROBLEMS VERSUS EXERCISES I frequently encounter discussions among parents about repetitive school math lessons, so a few years ago I prepared this Frequently Asked Question (FAQ) document about the distinction between math exercises (good in sufficient but not excessive amount) and math problems (always good in any amount). Most books about mathematics have what are called "exercises" in them, questions that prompt a learner to practice the concepts discussed in the mathematics book. By reading one mathematics book, and then several more, I learned that some mathematicians draw a distinction between "exercises" and "problems" (which is the terminology generally used by the mathematicians who draw this distinction). I think this distinction is useful for teachers and learners to consider while selecting materials for studying mathematics, so I'll share the quotations from which I learned this distinction here. I first read about the distinction between exercises and problems in a Taiwan reprint of a book by Howard Eves. "It is perhaps pertinent to make a comment or two here about the problems of the text. There is a distinction between what may be called a PROBLEM and what may be considered an EXERCISE. The latter serves to drill a student in some technique or procedure, and requires little, if any, original thought. Thus, after a student beginning algebra has encountered the quadratic formula, he should undoubtedly be given a set of exercises in the form of specific quadratic equations to be solved by the newly acquired tool. The working of these exercises will help clinch his grasp of the formula and will assure his ability to use the formula. An exercise, then, can always be done with reasonable dispatch and with a minimum of creative thinking. In contrast to an exercise, a problem, if it is a good one for its level, should require thought on the part of the student. The student must devise strategic attacks, some of which may fail, others of which may partially or completely carry him through. He may need to look up some procedure or some associated material in texts, so that he can push his plan through. Having successfully solved a problem, the student should consider it to see if he can devise a different and perhaps better solution. He should look for further deductions, generalizations, applications, and allied results. In short, he should live with the thing for a time, and examine it carefully in all lights. To be suitable, a problem must be such that the student cannot solve it immediately. One does not complain about a problem being too difficult, but rather too easy. "It is impossible to overstate the importance of problems in mathematics. It is by means of problems that mathematics develops and actually lifts itself by its own bootstraps. Every research article, every doctoral thesis, every new discovery in mathematics, results from an attempt to solve some problem. The posing of appropriate problems, then, appears to be a very suitable way to introduce the student to mathematical research. And it is worth noting, the more problems one plays with, the more problems one may be able to pose on one's own. The ability to propose significant problems is one requirement to be a creative mathematician." Eves, Howard (1963). A Survey of Geometry volume 1. Boston: Allyn and Bacon, page ix. I have since read about this distinction in several other books. "Before going any further, let's digress a minute to discuss different levels of problems that might appear in a book about mathematics: Level 1. Given an explicit object x and an explicit property P(x), prove that P(x) is true. . . . Level 2. Given an explicit set X and an explicit property P(x), prove that P(x) is true for FOR ALL x [existing in] X. . . . Level 3. Given an explicit set X and an explicit property P(x), prove OR DISPROVE that P(x) is true for for all x [existing in] X. . . . Level 4. Given an explicit set X and an explicit property P(x), find a NECESSARY AND SUFFICIENT CONDITION Q(x) that P(x) is true. . . . Level 5. Given an explicit set X, find an INTERESTING PROPERTY P(x) of its elements. Now we're in the scary domain of pure research, where students might think that total chaos reigns. This is real mathematics. Authors of textbooks rarely dare to pose level 5 problems." Graham, Ronald, Knuth, Donald, and Patashnik, Oren (1994). Concrete Mathematics Second Edition. Boston: Addison-Wesley, pages 72-73. This digression becomes the subject of a, um, problem in Exercise 4 of Chapter 3: "The text describes problems at levels 1 through 5. What is a level 0 problem? (This, by the way, is NOT a level 0 problem.)" "First, what is a PROBLEM? We distinguish between PROBLEMS and EXERCISES. An exercise is a question that you know how to resolve immediately. Whether you get it right or not depends on how expertly you apply specific techniques, but you don't need to puzzle out what techniques to use. In contrast, a problem demands much thought and resourcefulness before the right approach is found. . . . "A good problem is mysterious and interesting. It is mysterious, because at first you don't know how to solve it. If it is not interesting, you won't think about it much. If it is interesting, though, you will want to put a lot of time and effort into understanding it." Zeitz, Paul (1999). The Art and Craft of Problem Solving. New York: Wiley, pages 3 and 4. ". . . . As Paul Halmos said, 'Problems are the heart of mathematics,' so we should 'emphasize them more and more in the classroom, in seminars, and in the books and articles we write, to train our students to be better problem-posers and problem-solvers than we are.' "The problems we have selected are definitely not exercises. Our definition of an exercise is that you look at it and know immediately how to complete it. It is just a question of doing the work, whereas by a problem, we mean a more intricate question for which at first one has probably no clue to how to approach it, but by perseverance and inspired effort one can transform it into a sequence of exercises." Andreescu, Titu & Gelca, Razvan (2000), Mathematical Olympiad Challenges. Boston: Birkhäuser, page xiii. "It is easier to advance in one topic by going ahead with the more elementary parts of another topic, where the first one is applied. The brain much prefers to work that way, rather than to concentrate on ugly technical formulas which are obviously unrelated to anything except artificial drilling. Of course, some rote drilling is necessary. The problem is how to strike a balance." Lang, Serge (1988), Basic Mathematics. New York: Springer-Verlag, p. xi. "Learn by Solving Problems "We believe that the best way to learn mathematics is by solving problems. Lots and lots of problems. In fact, we believe the best way to learn mathematics is to try to solve problems that you don't know how to do. When you discover something on your own, you'll understand it much better than if someone just tells it to you. . . . . "If you find the problems are too easy, this means you should try harder problems. Nobody learns very much by solving problems that are too easy for them." Rusczyk, Richard (2007). Introduction to Algebra. Alpine, CA: AoPS Incorporated, p. iii.

vasco 15y ago

Isn't it required to be at least 13 years old to have a google account? How does this affect the kids who want to use khanacademy? Are they forced to have a facebook account? EDIT: Actually, facebook also has a minimum age requirement of 13 (https://www.facebook.com/help/?faq=210644045634222 https://www.facebook.com/help/?faq=210644045634222). Can't see how khanacademy missed that. I think this is a major flaw in their signup system. Should they (khanacademy) really be blocking every kid younger then 13? EDIT2: It seems like they address it here (http://www.khanacademy.org/about/getting-started http://www.khanacademy.org/about/getting-started) but their solution is having the parents create an account for the kids. I don't really think this is actually acceptable by facebook's terms of service though, not sure about google. See point 4 in https://www.facebook.com/terms.php https://www.facebook.com/terms.php

corysama 15y ago
From http://www.khanacademy.org/about/getting-started http://www.khanacademy.org/about/getting-started ----------------------- If your students are under 13: You currently have two options: you can sign your school up for Google Apps for Education, which will help you provide each student with a Google account that can be used with Khan Academy, or you can have your students' parents individually create accounts for each student on either Google or Facebook. We are constantly working to improve this situation, but that's the best we've got at the moment (sorry!). If you already have Google Apps for Education accounts but aren't able to use them to sign in on the Khan Academy, you might need to upgrade your account.
- vasco 15y ago
  That's only for people with Google Apps for Education (teachers)!! Also, if you are under 13 you can't use the site if you didn't sign up with google/facebook (which have their own weird under 13 rules) See "1. Eligibility" in (http://www.khanacademy.org/about/tos http://www.khanacademy.org/about/tos) EDIT: Also, I found out that youtube actually doesn't let anyone under 13 use their service, so I'm guessing you can't watch the videos either if you're under 13. See "12. Ability to Accept Terms of Service" in (http://www.youtube.com/static?gl=US&template=terms http://www.youtube.com/static?gl=US&template=terms) I just found out the internet is just for people over 13...

pixcavator 15y ago

I'd be much more impressed it these (or at least a part of them) were paying customers.

solutionyogi 15y ago
Why? Khan Academy is a non profit organization. They are not looking to make money. They are trying to change the world of education. I am impressed by these numbers because it means that more people are now aware that there is a quality free resource where they can educate themselves.
- pixcavator 15y ago
  Why would it be more impressive? Because paying customers vote with their money. Money is a better validation than "you're great!".
  - solutionyogi 15y ago
    Yes, money is a validation if your goal is to make money. If I am a for-profit company and I show you millions of visitors for my website but no real revenues, I would agree that it's not impressive. As the other commentator pointed out, their goal is not to make money. And this is impressive because it's a huge progress towards their stated goal.
corysama 15y ago
"We're a not-for-profit with the goal of changing education for the better by providing a free world-class education to anyone anywhere." http://www.khanacademy.org/about http://www.khanacademy.org/about
- pixcavator 15y ago
  Non profit != no charge
  - 15y ago

dbbo 15y ago

I found some of Khan's orgo videos helpful review material. In fact, the doctorate-level professor I had didn't do a much better job (if at all better) of explaining the material the first time around.