Review of Khan Academy by Xah Lee

Perm URL with updates: http://xahlee.org/math/khan_academy_review.html

So the other day i looked at Khan Academy. Spent a hour to watch a few videos. I find it fantastic, but also disapppointing. Let me explain. (If you don't know already: Khan Academy is a online educational site, basically just thousands of videos, each about 10 minutes. Website at: khanacademy.org)

Khan Academy logo

The Bad

Here's the disappointing parts:

Basics Only. Of all their courses of various subject areas (e.g. sciences, humanities, etc.), the level offered is about first year of university course. At best 2nd year university course.

For example, one of the subject they are known for and have the most number of videos is math. Vast majority of them are highschool level (e.g. fraction arithmetic, highschool algebra, etc.). The most advanced course they offer are: {calculus, linear algebra, differential equations}. This means, if you are a math fan, and you have studied first 2 years of university math, then Khan Academy doesn't do anything for you. (for example, they don't even have basic group theory or basic abstract algebra)

Video Format is Slow. They teach by videos. The Video format is a fixed and slow format. Very time consuming. I'm impatient to sit there and wait for the lecture to go thru second-by-second. In comparison, when learning a subject i don't know (e.g. bio-chemistry), i prefer a encyclopedia such as Wikipedia, where i can read fast, scan parts i already know, delve into parts i want to learn more.

Few Subject Areas. Although they have thousands of videos, but they don't really have coverage of wide range of topics. For example, in the category of Computer Science, all they have is ~30 videos on the very basics of programing Python. That is ALL they have on computer science. Paucity is the word. For what they cover, it's about equivalent of 1 day's worth of reading a python book, and you'd learn much more in depth.

The Good

Here's the fantastic parts:

Basics is Good. Although the level covered are rather basic, but that's also the good part about it. I know math well, but i'm rather ignorant in vast majority of other topics. For example: economics, law, art history, biology, finance, medicine, world history, anthropology, …, etc. This applies to basically everyone. This means, for vast majority of people, the majority of courses offered by Khan Academy are very useful.

Video Format is Engaging. The slow video format also has good aspects. For example, now and then i want to broaden my understanding of law, or art history, subjects that i do not have strong interest. Reading encyclopedia is a very dry experience, and requires high level of concentration. It gets boring and aimless fast. But well arranged course in videos with human voice that guides you thru, is very satisfying. You can sip a drink and passively enjoy the video and learn something.

Today there are more and more free online courses or educational materials. Next i'll be looking into Stanford's offers on computer science machine learning.