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New Khan Academy Exercise Framework Is Live

156 points by rubergly 15y ago

solutionyogi 15y ago
From the source code: // Yuck! There is no god. John will personally gut punch whoever thought this was a good API design. https://github.com/Khan/khan-exercises/blob/master/khan-exercise.js#L180 https://github.com/Khan/khan-exercises/blob/master/khan-exer... :)
- jeresig 15y ago
  Heh yeah, the Mathjax API is rather awful. Tons of separate file requests, configuration is only designed to work in inline script tags, and other ugliness. We've been experimenting with MathQuill - it's way faster and much more lightweight. Unfortunately it doesn't have all the features that we need otherwise we'd switch right away. http://laughinghan.github.com/mathquill/ http://laughinghan.github.com/mathquill/
rubergly 15y ago
The exercises are live at http://www.khanacademy.org/exercisedashboard http://www.khanacademy.org/exercisedashboard. We're really proud of the improvements we've made to the framework and how much easier we've made it to add new exercises; if you're interested in contributing, please fork the code at https://github.com/khan/khan-exercises https://github.com/khan/khan-exercises. We're working as fast as we can to fix any bugs that pop up, so we'd appreciate reporting any issues using the "Report a Problem" link at the bottom of every exercise page.
- zerohp 15y ago
  I'm a 33 year old self-taught software developer, that originally skipped college, who is starting at a local community college this fall with plans to transfer to Illinois for Computer Engineering. I can't express how much your team and Mr Khan have helped me. In June I spent one to two hours a day watching videos and completing exercises to prepare for my schools placement exam. Starting from the beginning, not only did I refresh my memory but also learned essential concepts that my high school education did not cover. Thanks to your site I placed at the highest level my school will place an incoming freshmen for mathematics. I'm looking forward to finishing off the last 4 exercises and hope to see more soon. I would be very nervous about both working and going to school full time, during my first year, without Khan Academy helping me get a head start before the semester starts. The high quality lectures and exercises you provide are fantastic for someone like me who may not have the ability to attend office hours and tutoring as much as a conventional student. Thank you for all that you're doing. It's revolutionary.
tybris 15y ago
Almost makes me want to go to school again.
- alanfalcon 15y ago
  It's available to anyone and everyone, even you! Right now!
tnorthcutt 15y ago
John (and others working on Khan Academy), I've known about Khan Academy for 6 months to a year. Recently, however, I've started to become MUCH more interested in it. I'm starting to feel a strong pull towards doing things to help people in my local community - specifically through education. I think there's a lot of potential for Khan Academy to play a significant role in that. I haven't started something concrete yet, but wanted to take this opportunity to thank you and everyone else working on Khan Academy for what you're doing. I think it's extremely important and valuable work.
aik 15y ago
Good stuff -- the simplification of the code is exciting for sure and is bound to encourage more to join to create more problems (it has for me!) One question/problem/concern: Just for fun I tried out the "Linear equations 1" problem section. So I just got the problem "Solve for x: 9x = 6". Naturally I could answer 2/3 and would expect a happy face, however I decided to answer 6/9, also a true answer, to try the system out. I was received with a sad face (incorrect answer). But, why? The solution is actually true -- it's just missing the artificial target the website has set. The site doesn't explain that it wants the lowest denominator (just "Solve for x"). I would think this to be misleading -- what do you think? How could the proper lesson be enforced here? How and why should students assume 2/3 is right and not 6/9? There's a danger here of students looking for the answer the system wants (extrinsic motivator) rather of what they have found to be right and then denied the satisfaction. I would expect a happy face with 6/9. It seems to me that the problem should allow multiple answers -- or for the goals of the lesson to be more detailed (and perhaps include an explanation/recommendation after the fact of what the problem is really asking for).
- heresy 15y ago
  Or they just want to test that they can reduce a fraction? This was a common requirement when I was in primary school.
  - aik 15y ago
    I completely agree -- and I could easily understand that someone would assume that's what is being asked, but would a child assume that (never being told that is the goal)? Should they have to assume that? I don't see why -- that seems to only "schoolify" them. Giving students incorrect answers only in order to conform them to the workings of the system is potentially damaging.
    - zerohp 15y ago
      I think they would assume that if they had watched the lectures. I can't recall a single one where the final answer wasn't reduced.
qq66 15y ago
It's great that Khan Academy has a 100x engineer even though some have said they don't need one. This can be a 100-year project and having a solid technical foundation will allow it to become one.
- jpulgarin 15y ago
  Does 100x, mean full time? Khan Academy has various full-time engineers.
  - qq66 15y ago
    The term "10x" engineer refers to engineers who are 10 times as productive as the average engineer, largely because they create better abstractions, solve metaproblems, and make maintainable code (they generally can't type 10x as fast). Resig is at least 100x in this department but if you really tally up the impact of JQuery etc. it's probably even more than that. Then there are the (infinity)x guys like Torvalds.
  - mnutt 15y ago
    I assume that is referring to Paul Graham's assertion that a good developer isn't just a little better than an average developer, but is instead orders of magnitude better.
    - asg 15y ago
      This assertion (among many other gems) was originally stated in the Mythical Man Month, by Fred Brooks, published in 1975.
pbhjpbhj 15y ago
Supposing many more problems sets are added, how're they going to manage this proliferation. My 6yo has been using it for a little while - I've not investigated it deeply but it seems that videos and exercises are quite tightly paired. Having many more exercise [overlapping] sets would make it hard to choose which to do. It seems the whole system wouldn't work as well with an open access method of submitting exercises, so what's this leading towards? Aside: I think the scratch pad could be vastly improved. When my 6 yo is doing addition/subtraction trying to write out a number line on the scratchpad is harder for them than doing the sums, it gets in the way. Of course he uses a pieces of paper instead but that seems a bit silly. They could integrate a number line drawing tool, ...
neilk 15y ago
If I understand correctly, some templating transforms the <var>s, etc., into JavaScript. Why not write the JS as a regular program? The syntax you have doesn't seem dramatically easier than just ordinary JS and has to be a bit confining. Is it really that repetitive, or does the code need to be expanded in different ways in different contexts?
- bbq 15y ago
  I'm wondering the same thing. I imagine with CoffeeScript it could look very nice.

156 points by rubergly 15y ago

From the source code: // Yuck! There is no god. John will personally gut punch whoever thought this was a good API design. https://github.com/Khan/khan-exercises/blob/master/khan-exercise.js#L180 https://github.com/Khan/khan-exercises/blob/master/khan-exer... :)

jeresig 15y ago
Heh yeah, the Mathjax API is rather awful. Tons of separate file requests, configuration is only designed to work in inline script tags, and other ugliness. We've been experimenting with MathQuill - it's way faster and much more lightweight. Unfortunately it doesn't have all the features that we need otherwise we'd switch right away. http://laughinghan.github.com/mathquill/ http://laughinghan.github.com/mathquill/

rubergly 15y ago

The exercises are live at http://www.khanacademy.org/exercisedashboard http://www.khanacademy.org/exercisedashboard. We're really proud of the improvements we've made to the framework and how much easier we've made it to add new exercises; if you're interested in contributing, please fork the code at https://github.com/khan/khan-exercises https://github.com/khan/khan-exercises. We're working as fast as we can to fix any bugs that pop up, so we'd appreciate reporting any issues using the "Report a Problem" link at the bottom of every exercise page.

zerohp 15y ago
I'm a 33 year old self-taught software developer, that originally skipped college, who is starting at a local community college this fall with plans to transfer to Illinois for Computer Engineering. I can't express how much your team and Mr Khan have helped me. In June I spent one to two hours a day watching videos and completing exercises to prepare for my schools placement exam. Starting from the beginning, not only did I refresh my memory but also learned essential concepts that my high school education did not cover. Thanks to your site I placed at the highest level my school will place an incoming freshmen for mathematics. I'm looking forward to finishing off the last 4 exercises and hope to see more soon. I would be very nervous about both working and going to school full time, during my first year, without Khan Academy helping me get a head start before the semester starts. The high quality lectures and exercises you provide are fantastic for someone like me who may not have the ability to attend office hours and tutoring as much as a conventional student. Thank you for all that you're doing. It's revolutionary.

tybris 15y ago

Almost makes me want to go to school again.

alanfalcon 15y ago
It's available to anyone and everyone, even you! Right now!

tnorthcutt 15y ago

John (and others working on Khan Academy), I've known about Khan Academy for 6 months to a year. Recently, however, I've started to become MUCH more interested in it. I'm starting to feel a strong pull towards doing things to help people in my local community - specifically through education. I think there's a lot of potential for Khan Academy to play a significant role in that. I haven't started something concrete yet, but wanted to take this opportunity to thank you and everyone else working on Khan Academy for what you're doing. I think it's extremely important and valuable work.

aik 15y ago

Good stuff -- the simplification of the code is exciting for sure and is bound to encourage more to join to create more problems (it has for me!) One question/problem/concern: Just for fun I tried out the "Linear equations 1" problem section. So I just got the problem "Solve for x: 9x = 6". Naturally I could answer 2/3 and would expect a happy face, however I decided to answer 6/9, also a true answer, to try the system out. I was received with a sad face (incorrect answer). But, why? The solution is actually true -- it's just missing the artificial target the website has set. The site doesn't explain that it wants the lowest denominator (just "Solve for x"). I would think this to be misleading -- what do you think? How could the proper lesson be enforced here? How and why should students assume 2/3 is right and not 6/9? There's a danger here of students looking for the answer the system wants (extrinsic motivator) rather of what they have found to be right and then denied the satisfaction. I would expect a happy face with 6/9. It seems to me that the problem should allow multiple answers -- or for the goals of the lesson to be more detailed (and perhaps include an explanation/recommendation after the fact of what the problem is really asking for).

heresy 15y ago
Or they just want to test that they can reduce a fraction? This was a common requirement when I was in primary school.
- aik 15y ago
  I completely agree -- and I could easily understand that someone would assume that's what is being asked, but would a child assume that (never being told that is the goal)? Should they have to assume that? I don't see why -- that seems to only "schoolify" them. Giving students incorrect answers only in order to conform them to the workings of the system is potentially damaging.
  - zerohp 15y ago
    I think they would assume that if they had watched the lectures. I can't recall a single one where the final answer wasn't reduced.

qq66 15y ago

It's great that Khan Academy has a 100x engineer even though some have said they don't need one. This can be a 100-year project and having a solid technical foundation will allow it to become one.

jpulgarin 15y ago
Does 100x, mean full time? Khan Academy has various full-time engineers.
- qq66 15y ago
  The term "10x" engineer refers to engineers who are 10 times as productive as the average engineer, largely because they create better abstractions, solve metaproblems, and make maintainable code (they generally can't type 10x as fast). Resig is at least 100x in this department but if you really tally up the impact of JQuery etc. it's probably even more than that. Then there are the (infinity)x guys like Torvalds.
- mnutt 15y ago
  I assume that is referring to Paul Graham's assertion that a good developer isn't just a little better than an average developer, but is instead orders of magnitude better.
  - asg 15y ago
    This assertion (among many other gems) was originally stated in the Mythical Man Month, by Fred Brooks, published in 1975.

pbhjpbhj 15y ago

Supposing many more problems sets are added, how're they going to manage this proliferation. My 6yo has been using it for a little while - I've not investigated it deeply but it seems that videos and exercises are quite tightly paired. Having many more exercise [overlapping] sets would make it hard to choose which to do. It seems the whole system wouldn't work as well with an open access method of submitting exercises, so what's this leading towards? Aside: I think the scratch pad could be vastly improved. When my 6 yo is doing addition/subtraction trying to write out a number line on the scratchpad is harder for them than doing the sums, it gets in the way. Of course he uses a pieces of paper instead but that seems a bit silly. They could integrate a number line drawing tool, ...

neilk 15y ago

If I understand correctly, some templating transforms the <var>s, etc., into JavaScript. Why not write the JS as a regular program? The syntax you have doesn't seem dramatically easier than just ordinary JS and has to be a bit confining. Is it really that repetitive, or does the code need to be expanded in different ways in different contexts?

bbq 15y ago
I'm wondering the same thing. I imagine with CoffeeScript it could look very nice.