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Show HN: Khan-dl – Khan Academy Course Downloader (github.com/rand-net)
473 points by rand_net on Feb 14, 2021 | hide | past | favorite | 173 comments


I will comment about larger scale. Recently I realized that if I find something interesting, it's worth downloading and saving it immediately.

I may never use it again, so simple garbage collection script does it for me, but it's much better than going to youtube/another source and find something "author made video private", "channel was removed".


How often does that happen to you? I basically just watch Youtube videos all day, and often dig up old playlists and lectures. This hasn't ever been a problem for me. In my case, if I were to do it, this would basically be me being a hoarder :)


Berkeley posted a bunch of free course content. They got sued under ADA because they hadn't captioned the material. Rather than go back and caption everything they removed the material.

Another example was Walter Lewin's physics videos all got pulled by MIT from Open Courseware (but are available on YT at least).

Not a comment about the parties involved, just saying there's external factors sometimes that will vanish a video.

https://www.insidehighered.com/news/2017/03/06/u-california-...

https://www.insidehighered.com/news/2015/03/10/despite-mits-...


> Berkeley posted a bunch of free course content. They got sued under ADA because they hadn't captioned the material.

This sort of thing really bothers me. Accessibility should absolutely be supported where feasible, but never to the point where it prevents releasing content in the first place.


Not even when you knew about the law and its requirements, violating their own university policies, having professors committing fraud by attesting their course materials were accessible, etc? Read the DoJ findings below, Berkeley is not a victim here in my opinion.

Regardless, no one said Berkeley had to take the videos down. They chose to do that on their own because it was too “expensive” to make them accessible.

However, I did not see Berkeley turning down federal funding, which is in part why they are legally required to make their courses accessible (Section 504, for those wondering). Funny how that stuff works.

https://www.ada.gov/briefs/uc_berkley_lof.pdf


I can't speak to any of that, but it strikes me as a separate issue.

The question is, if a college professor would like to throw up a recording of their course online for the public benefit, and the school would otherwise be on board, will they be able to do so? Or will the school be concerned about getting sued because the video doesn't have subtitles?

Adding subtitles to many hours of lectures which will be posted for free is not a reasonable request. So of course what will happen instead is the videos will never be posted.

If this scenario isn't actually plausible, feel free to correct me.


The courses are not free, they are paid for, in large part, by the federal government and the state.

California did not back then, but they now have their own legislation known as the Unruh Civil Rights Act and of course there’s the ADA/Rehabilitation Act.

Here’s the kicker - they have to do this whether it is posted publicly or not. The legal requirement does not only apply to public material, but to ALL material and the material still exists/can be accessed with Berkeley credentials. It also applies to future material produced that is used with students/in classes.

My guess is, they had to make it accessible regardless and did this out of spite. They had internal resources to help with this but chose not to do so/made it really expensive because of the volume due to not doing it in the first place.

It is kind of like Cybersecurity - people don’t like to spend the money until they have a breach, where it’s much more expensive to remediate and their costs would be much more manageable/risk reduced has they done it “right” the entire time.

My mother is a professor in the CSU system and I will say California public universities are beginning to take this much more seriously now, largely because of lawsuits.


> The courses are not free, they are paid for, in large part, by the federal government and the state.

The courses are not free but the videos are! Releasing publicly available videos is not a requirement in order to receive public funding, it's something extra they did because they could.

> My guess is, they had to make it accessible regardless and did this out of spite. They had internal resources to help with this but chose not to do so/made it really expensive because of the volume due to not doing it in the first place.

If the subtitles were already available for students internally, that does change things. But the articles posted by the OP made it sound like it was something they'd need to add.

And adding subtitles to hundreds of hours of lectures really does strike me as unreasonably costly, given that this content was not intended for students paying tuition and did not garner any additional funding.


I think it is a bit naive to think they released those videos out of altruism. It is free marketing for them and a way of distinguishing their brand, funded by students, the state, and the federal government.

They had an office dedicated to helping professors make course materials, to include resources for subtitling course material and QA processes for ensuring accessibility. For whatever reason, the university did not require use of the office and the professors did not use it even though it was there. The DoJ report I linked above has additional information on that.

I may not be remembering accurately, but I am fairly sure the material Berkeley posted on edX at the time was just recordings of their actual lectures given to on-campus students and/or recordings they were making/were made for online classes (that were paid for). In other words, they were not going out of their way to record these lectures specifically for MOOCs.


Are you suggesting that Berkeley doesn’t have the resources to properly add audio transcripts to their course content?

It really feels like the Overton window on disability rights has shifted in the wrong direction.

Just because it’s free, the university has certain obligations from taking federal funding. These laws have been put into place in order to ensure disabled people have equal access to these educational systems.

One way to solve this would have been for Berkeley to charge a nominal fee (perhaps for a limited time as “early access” or similar) that could then be used to pay people that can transcribe the audio.

Instead, a lack of imagination and a lack of empathy leads to these resources being removed, a net loss for everyone.


Sounds to me like the way the law is enforced should change then. There should be a fine for not following the law if the content is removed or not updated. If the fine is sufficiently high, then there will be no incentive to just remove the content. There will still be a disincentive to create it in the first place, but at least existing content won't disappear.


This seems like a poor idea.

1. Release content not due to requirement but for general good. 2. Get sued because it's not captioned. 3. Have insufficient funds to caption so you pull material. 4. Get fined for pulling material. 5. Watch as no one does step 1 anymore.


It's not a requirement for everyone. Just federally funded groups. Also, these, days, I'm pretty sure you can just turn on captioning and youtube will use voice recognition to do a decent job of captioning your video for free.


I agree with you, since unfortunately the only real way to enforce the ADA is through private citizens filing civil suit.

Regardless, a lack of more effective means for enforcement does not absolve Berkeley of failing to follow the law, especially when they had internal resources to make their material accessible and chose not to do so.

Edit: apologies, misread your post and that is an interesting approach. Another way is to make the university pay back a portion of the federal funding they received, up to whatever amount they estimate it would take to make the materials accessible.


Youtube's auto CC feature gotten very good lately, I think it can handle most of the stuff with clear sound. So hopefully auto CC will help to solve this unfortunate paradox of accessibility.



Wait, Walter Lewin's videos are gone...?


MIT policy on sexual harassment was found to be violated.

https://news.mit.edu/2014/lewin-courses-removed-1208


So what? Report him to the police, do an investigation, fire him if he really did what he's accused of, let the court deal with the rest... I don't know why removing him from the internet helps.


Removing a persona non-grata and their related authored material may serves multiple purposes:

- The organization signaling to stakeholders that they condemn and take appropriate action against behaviour.

- The organzation engaging in damage control, minimizing future exposure of events linking back to the organization.

- Penalizing transgressive behaviour in a professional setting, through sanctions and revocations of merit, reputation, licensing or employment etc.

Actually, breach of contract could lead to lecture material not being legally available, if a lecturer has sole ownership of such. It could also be that future use of say, recorded lectures, involves compensation to the author. If an organization want to cut ties to the author, or just withhold compensation for a time, they might refrain from using the authors material.


My initial gut feeling was your response, but changed my mind quickly when reading the article. His videos being online resulted in interaction with the students, and that's where he harassed them.

It's a shame, but any other solution feels like it's a broken stair just waiting for someone to trip over it.


Because interacting with students on the Internet is how he harassed people?



Auto captions are plenty good enough to understand material nowadays. And they'll only get better with time.

Considering that, we should remove overzealous captioning laws and simply require auto-captions and focus our accessibility efforts elsewhere in society (like making more new build houses step free - it's ridiculous that 90% of my friends houses I can't visit).


When I go through my YouTube favorites playlist, about a third of them are now removed. I’ve been adding things to it for over a decade. If there’s something you might possibly want to watch again in the future, download it. Bit rot is a real thing.

But at least YouTube tells you something was removed, although I do wish they would tell you what it was which was removed. I was an active google music user for the life of the service (RIP) and sometimes I would have a vague thought that it felt like my playlist was missing something but they never actually told you. It was infuriating.

The cloud is ephemeral, do not rely on it.


It’s particularly annoying that YouTube doesn’t even tell you what it was that was hidden.


Exactly. At least tell me the dang title so I can find a replacement. Sad how many of my old song playlists, listened in a much different era of my life, are deleted and I’ll never remember what they were.


My old trance playlist is gone :( I spent nights just to find the name of a single one of the songs and couldn't.


> How often does that happen to you?

Even if it happens only once, it may be a really sad event. I had a "go-to" youtube video (nothing relevant in the grand scheme of things, just a beautiful rendition of a famous neapolitan song in the original language, not in italian). I listened very often because it cheered me up. Now it's gone for good and I'm sure I won't ever be able to listen to it. It was not a record, just a lady singing in a public place, obviously recorded with a phone.


I find a bunch of things on youtube, videos longer than 1 minute, that i add to "watch later" list, to well... watch later. Some things i watch the same day, some are there to stay.

Around 10-20% of the older videos are gone... from copyright infringements (music in video), to deleted channels, to "not available in your country). What I hate the most is, that even the video titles are removed, so i have no idea what's gone, just the "[Private video]" or "[Delted video]" in the list.


Yeah, which I'm sure is a capitulation to rightsholders that is not required by law.


I am registered on YouTube since January 2007. Right now in my YouTube playlists I have inaccessible:

- 6 out of 71 videos in favourites,

- 20 out of 209 in playlist of videos I consider interesting;

- 7 out of 56 in playlist I keep to give links to other people;

- 15 out of 112 in playlist of funny videos;

- 27 out of 218 in playlist of WTF videos;

- zero out of 89 in music video playlist;

- 19 out of 121 in political video playlist.


Similarly-old account here, and yeah - 10%-ish loss on average fits all my longer-standing / high-value playlists as well.

Especially when it comes to educational or conference content, those accounts seem to close with higher frequency.


The worst part is that you can't even see the name of removed videos.


Just to pile on the anecdotal evidence with a similarly old account-- most of my playlists are littered with gray boxes of unavailability as well.


Quite common, depending on what you're after.

Pornhub and its sisters recently dumped pretty much everything by unverified users thanks to an NYT hit-piece. Depending on your interests a lot of content went goodbye.

Youtube frequently delists music videos.

Creators sometimes remove old videos for various reasons.

Shit like this is why the cloud is not to be trusted.


Don't even trust "private" cloud storage. I used google docs in school and randomly they locked one of my documents that I needed to work on citing "tos violation". Week later the document was unlocked but I will never trust them again.


> Shit like this is why the cloud is not to be trusted.

Exactly.

No such thing as "the cloud" it's just other people's computers.


Video essays with fair use clips will randomly get purged by content ID or direct DMCA enforcement, even months or years after the video is originally uploaded. Sometimes the creator will trim out those bits and reupload it, but of course the original video in your playlist maybe permanently dead. And if it's an older video (or inactive account) they may not bother fixing it at all.


Pornhub deleted videos that were unverified because a number of them involved children and victims of human trafficking and abuse. The group Exodus Cry set up a campaign called TraffickingHub to bring attention to it. The New York Times did report on it, but it doesn't qualify as a "hit piece":

https://www.nytimes.com/2020/12/04/opinion/sunday/pornhub-ra...


> Pornhub deleted videos that were unverified because a number of them involved children and victims of human trafficking and abuse.

Indeed, but they through the baby out with the bathwater on that one. A tiny percentage of the content they deleted met that criteria.


So? Your original comment still say hit piece when it was in no way that and you seem to acknowledge that in the follow up.


Because it was a hit piece. A victim's advocates group pulled a stunt called "TraffickingHub" -- a gross, gross overstatement of the problem just by looking at the name -- and the NYT covered it because they love to report on that stuff. The problem was overblown in every possible angle, and PH moved to cover their ass.


An article is a hit piece if it lies or distorts the truth. Can you point out where the New York Times did this for this article?


They lost all of that content because they were not moderating their uploads to begin with. Whatever valuable content that was lost, if any, was purely because of their failure to police their own site.


It was better when they didn't police it. There are other ways to censor trafficking content.


Like what?


> Youtube frequently delists music videos.

I think you mean companies/YouTubers themselves - YT doesn't remove regular videos on their own very often. The content being deleted is still a problem and reason to save it though - many externalities might be reason for the uploader to remove videos (legal, purging a Google account, etc).


They do, through DMCA enforcement. But you are right that it is a combination of YouTube, publishers, and creators delisting things


Not OP, but I had a YouTube playlist that really was a collection of memories since I began university 10 years ago. Lots of things that are related to precious memories I had there: memes, inside jokes (so many Skyrim references), etc.

It had over a thousand videos from what I remember in 2015. Now there's barely ~600 left. Lots of them got deleted due to copyright, the Vox Adpocallispe (thx Carlos Maza) and cancel culture.

I just downloaded all the remaining video using youtube-dl but I should have done that before, now it feels I lost something important in those memories that I will never get back.

Here's the command I used, took me a while and might save other people a few hours:

pip install --upgrade pip

pip install youtube-dl

youtube-dl.exe -i -f bestvideo+bestaudio --merge-output-format mp4 "https://www.youtube.com/playlist?list=XXXXXXXXXXXXXXXXXXXXXX..."

Obviously if you're not on Windows remove the .exe

This will download an entire playlist at the highest video and audio quality and will not crash if a video has an error.


It will show "deleted video". If you copy the link of that and search the unique portion, you will often find google or other sites referencing the name of it, which you can use to find a reuploaded version


Note: even on Windows you don't need to specify .exe, unless there also happens to be a .com or .bat with the same name in the PATH.


It's a good idea to add -w/--no-overwrite (or --output TEMPLATE with autonumber) to that command line so you don't clobber your existing files, for safety.

EDIT: YT does not send a 0byte file for deleteds, only a "video unavailable" error.


bestaudio and bestvideo get it very wrong - have a look at the output of -F and you'll see it selecting the 720P version (?)


"best: Select the best quality format represented by a single file with video and audio."

Not the same as bestvideo+bestaudio which will merge separate sources.


best video+bestaudio are the default format, so that argument can be omitted in the future if you want.


When I look at my favorite'd videos on Youtube, a huge fraction of the ones from before 2010 are gone (example: https://i.ibb.co/31vb8nd/Screen-Shot-2021-02-14-at-2-31-56-P...). OTOH a lot of the things that I found funny in 2009 now seem cringy to me, so the gaps in the playlist save me from uncomfortable introspection.


It's common. It's easy to notice if you save interesting videos to a playlist and go through them, say, a year or two later to find what to watch. And you don't even know what was deleted.


My old youtube favorites are full of [deleted video]. It doesn't even tell me what the title was, so I can't even begin to reconstruct the playlist from other sources.

Right down the memory hole. Your "favorites" aren't even yours.


Anecdotal, but in all my "watch later" playlists about 5%-10% videos now are "Deleted video".


YouTube suffers from DCMA. Too often useful content is pulled off the platform. Better to use NewPipe and download the goods before they're gone forever.


Happens to me all the time and very often the reason is "Video not available in your country".

Just because it doesn't happen to you doesn't mean it's not a problem for many of us.

It also depends on the type of content, InfoSec stuff disappears all the time while popular music videos probably never vanish. "Despacitio" is not going anywhere.


Ofteb enough that it's worth addressung


I frequently add videos to playlists, both educational content and music-related, and I see "video was removed" more often than I'd like.

I set up youtube-dl to fetch all videos in my playlists daily at 4am. Digital hoarding is very cheap.


It happens a lot for music.


When I see a video I want to watch, I always cluck watch later. I'm at like 600 videos. Right now, my second last added video, from 2 days ago, was deleted.

In my list I have at least 30 deleted videos.


I have youtube content that disappears frequently from playlists and the frustrating thing is that the title vanishes too so you don't even know what you saved/missing out on.


I would estimate about 1/4 of the videos in my favorites playlist are no longer available

I now have a machine specifically set up to download videos from my favorites playlist on a daily basis


Replace YouTube with porn and it happens all the time.


Approximately 50% of the YouTube videos in my playlist that I’ve added over the last four years are no longer available.


Recently, youtube started to remove a lot of videos of pentesting.


some great stanford CS class videos got yanked when the instructor got resigned due to misconduct.


I wonder why.. did the contract specify the content could only be visible as long as that instructor as on staff? Or was this cancel culture in action? I'm fairly confident that there was no misconduct occurring in the midst of a Stanford CS class with everyone in attendance.

I know you can't answer this question, I just find it frustrating that stuff gets removed for reasons unrelated to the content.


Depends on what you’re looking for. I’d say anecdotally it is between 5-15% missing for me.


Exactly. I would also add the fact every single native video player is better than YouTube in every aspect - a native UI works incomparably faster, a native player consumes much less CPU, it usually has more features and is handier to control. So I always download everything I feel curious about and then use MPV, VLC or a thumb drive and my dumb TV USB port to play it. I only watch online when I'm sure it's absolutely not worth the disk space nor time watching much of it.


I highly encourage anyone critical of this to have a look at your list of "Liked" YouTube videos and see just how many are now inaccessible.


If you end up archiving youtube content, consider stopping by my discord server. https://discord.gg/EJvS4kf

We maintain a list of content that various members have archived, such that when content is removed from youtube, people can direct inquiries to contributors who have archived that content.

It's a small way to keep track of what things have been successfully archived, and direct efforts toward at-risk channels.

(You can see the current list of user-archived content here: https://tinyurl.com/v4rpe9w)


considering storage is cheap, this seems like a great idea


The Covid crisis has exposed a lot of the disaster in public education. For many kids, the quality of education they receive is a function of the quality of the school and the quality of the teacher. This is non-sensical.

Kids can learn from online sources. So why should someone's education be tied to their school district or teacher quality?

I would love to have the local school system provide lab space, athletics, support services and one-on-one tutoring as necessary.

But the bulk should be delivered online. Sal Khan is comprehensive and brilliant, but perhaps someone out there is better at chemistry or art history. Regardless, every kid should be exposed to the "best" teacher of the subject. Why should a child's Algebra education be school or teacher dependent, when the best Algebra teacher on the planet is just 256kb/s away.


I think you're massively underestimating how difficult it is to teach students and how important the bond between student and teacher is.

Online resources are incredibly valuable as supplementary material but they can't replace the culture and bond of small group learning


Even in high performing schools, it is easy to find variance in child outcomes dependent on teacher. In nearly all schools, the “good” and the “bad” teachers are well known. Teachers unions having negotiated tenure after just a few years of employment prevent the firing of “bad” teachers.

In poor performing schools, there are multiple reasons for poor observed outcomes.

None of these need to happen.

Keep small group learning and have adults support learning. But there is no reason for a teacher to explain something when Khan academy has already done it and often done it far better.


> But there is no reason for a teacher to explain something when Khan academy has already done it and often done it far better.

Citation is needed here. I'm not buying that Khan Academy has better outcomes just because this is HN and the internet is cool.

Where is the evidence that Khan Academy is better?


Do you have experience teaching a group of 10+ students?

>But there is no reason for a teacher to explain something when Khan academy has already done it and often done it far better.

You're skipping the often difficult task of getting the students to properly engage with khan academy.


The real problem is that the demand for good teachers far exceeds the supply. As a result large numbers of kids are left under educated. Teachers unions deny the existence of bad teachers. The clearest evidence for bad teachers is the existence of good teachers. Similarly, the clearest evidence of bad schools is the existence of good schools.

Interestingly, you can find bad teachers and bad schools at all points of per pupil spending. Money is an important variable, but not the only significant variable effecting student outcomes.

I think we should radically rethink teaching. We can support much better outcomes for far more kids by reducing the dependance on the quality of your teacher, school and school district.

I think it would be easier to get kids to engage with Khan and online instruction in general than to fix failing school districts and failing schools. Use the schools as support. Many are already failing at their primary task as first line instructors - just take it off their plate.


> The real problem is that the demand for good teachers far exceeds the supply.

The current teaching model simply doesn't scale. It worked well in the past, when most people got like 4 years of elementary school, and a few selected ones studied longer. Now we want everyone to sit at the school desk as long as possible, and preferably in small classes. (Yes, I understand why small classes are better. I am just saying we can't afford them for everyone without compromising on teachers' quality.)

Just guessing the numbers: if people live 80 years on average, and spend maybe 15 years on average at school, that is like 20% of population being students. If you want 1 teacher per 20 students, that is 1% of population being teachers.

We all have an idea of what an "ideal teacher" should look like. And some of us actually met someone like that in real life.

But 1% of population having the required skills? Also, there are other professions competing for talent. If you make all good programmers teach computer science, who is going to write code? Similarly, who will do surgery, etc.

What currently happens is that rich people (plus a few lucky non-rich people) succeed to get the best teachers for their kids... and the rest have to deal with what is left for them.

With sources like Khan Academy, everyone on this planet could have a top-quality education. You only need to make the great video lecture once. It can even be translated to other languages by other people, who don't need to be good scientists or educators themselves, just good translators. Education could be free like, dunno, Linux or something.

And yes, having a good human teacher is better than watching video. I am just saying it is a luxury that most students don't get. But everyone could watch the great video. So maybe we could change the school to be more like... uhm, maybe watching the videos together at school, and then having a debate about them? Then doing the related online tests, and again having a debate about what went wrong?

We already accept written textbooks. We should do the same with videos.


> We already accept written textbooks. We should do the same with videos.

I think that the point of textbooks is to lower the required subject matter expertise bar for teachers, leaving them to focus on teaching the material.

Unfortunately, when a teacher is merely familiar with the material rather than understanding it deeply, they will find it difficult to explore multiple (valid) ways of explaining it to students until it 'clicks' for each one, which means students often fall back on rote memorization and mechanical competence.

A video of a good (even great) teacher is no more interactive than a textbook, so if the student doesn't happen to 'get' the explanation as it is presented they are going to fall back on memorization and mechanical competence in exactly the same way.

There are interactive learning environments with extensive libraries of content that explore material in multiple ways as needed (as indicated via assessments) by students, but AFAIK they are all proprietary.


The expertise of an average teacher is low, whether with textbooks or without them. For example, many math teachers at elementary schools fail at elementary school math. I have heard horror stories.

Without textbooks, it wouldn't be any better. Only the kids wouldn't have a secondary source of information.

I am completely in favor of having better teachers. I just don't see the way to find them, and people were already trying for decades, so whatever idea I would come up with, someone probably already tried it. (I know a few people who are working on a reform of mathematical education. It is from them that I know how the actual sitation is even worse than I imagined.)

> A video of a good (even great) teacher is no more interactive than a textbook

Agreed. Sometimes the video can contain helpful animations.

My hope is that the videos could be updated more flexibly than the books. When you print a book, the next version comes in a decade. There are known errors in textbooks, but no one is going to spend money to reprint them again, just to fix the errors. It we could have the books online, we could fix the errors as they are found... but most people are not going to read books online. However, with videos hosted online, I hope it would be possibly to, dunno, add the errata as subtitles, or something.

Another hope is greater fragmentation. A teacher is unlikely to recommend one chapter from one textbook, and another chapter from another textbook. Or recommend two textbooks, like "if you didn't understand the explanation in the first one, try the second one". With videos -- here I assume there would be a free version online -- this could be easier.

I have seen many videos recorded by teachers during COVID. Some of them quite ok, considering the authors are amateurs. But the thing I like most is that if you have five teachers that teach the same grade, and make the videos for the whole year, you get five alternative videos for each topic. Now when anyone says "I don't get it", you can easily give them four more links and maybe that will help.

Elementary school education is an area where you really need to think about how your solutions scale. If you do the right thing once, literally millions can benefit from it.


>The real problem is that the demand for good teachers far exceeds the supply.

There's a surefire way to increase the supply of good teachers, increase salaries & benefits. Reduce classroom sizes. Give teachers adequate time to plan engaging lessons and make personal connections with students, their families, and the community. Teaching is a miserable job with low autonomy, high stress, a low pay ceiling, a rigid pay scale, and is absolutely draining.

>We can support much better outcomes for far more kids by reducing the dependance on the quality of your teacher, school and school district.

Sure, but the whole point is that this is much easier said than done.

Do you have time in the classroom?


> There's a surefire way to increase the supply of good teachers, increase salaries & benefits. Reduce classroom sizes.

This has all been done to very, very little effect.

Reading, Math and Science scores are basically flat since 1970. K-12 employee numbers have almost doubled over the same period and costs per student have almost tripled.

https://www.cato.org/blog/public-school-spending-officials-v...


> Reduce classroom sizes. Give teachers adequate time to plan engaging lessons and make personal connections with students, their families, and the community.

Side note: This also increases demand for teachers, because any single teacher now teaches fewer students.

If you reduce class size by 1/3 you need 50% more teachers than before (at the same workload, to teach the same number of students). If you reduce class time by 1/3, you again need 50% more teachers.


I do not have classroom time. But I personally know some very good teachers. They work hard and are over burdened with full schedules, full classes and regulatory testing and lesson requirements that force them to keep a demanding pace. The ones that succeed in building meaningful relationships with students, parents and their community are standouts. These are often perceived as the "good" teachers. To me it appears they are rare because they are going well above and beyond what the job expects of them.

This is the problem. There aren't enough good teachers. Salaries/benefits/class size/prep time are a function of funding. Low autonomy/high stress are the result of our regulatory demands that appear to be on a one way direction: even more requirements and testing.

One particular friend left high end consulting to become a HS math teacher in an inner city school. He came with an academic background - having taught for a bit in colleges. Very optimistic. He left after 4 years because the number one problem in his classroom was keeping the kids focused at all. As he put if he had three concepts to cover in 50 minutes, he was lucky if could get 1 covered for the 2 or 3 students among the 30 that were trying to pay attention.

He was a good teacher and paid well. The school, school district, the community had complex problems: low income, crime, food insecurity, parents who had to work multiple shifts, etc. He couldn't solve all these problems before explaining right triangles.

I don't believe the model that we have today will survive the next 25 years.

I agree that good teachers and good schools are necessary. But we don't seem to be generating or supporting enough of them. So I think the solution is to look elsewhere entirely. Break up the problem. Remove the dependence on good teachers and good schools.

BTW, if you're a teacher. Thank you for what you do.


Like your friend, I couldn't cut it in the classroom and burnt out. Now I get paid almost 3 times as much with half the stress to program.

>So I think the solution is to look elsewhere entirely. Break up the problem. Remove the dependence on good teachers and good schools.

I think this comes to our fundamental disagreement. I just don't think this is possible nor a good path to pursue.

Thanks for taking the time to engage in the back and forth!


> >The real problem is that the demand for good teachers far exceeds the supply.

> There's a surefire way to increase the supply of good teachers, increase salaries & benefits. Reduce classroom sizes.

I don't disagree, but either one of those solutions alone is a pretty hard sell, trying for both at once isn't going to get much traction.

Personally, I suggest focusing on classroom size first, as it should improve the performance of existing teachers and at least make the job less unattractive to new teachers.


That's not necessarily a negative thing, you're forcing students to learn to engage with content online without someone spoon-feeding them.

I think my interest in programming as a kid pushed me to online learning and taught me to be independent. Most of my friends barely went beyond what the teacher covered.

I still think that school as an environment where you see and interact with other students and tutors is useful - but merely for a social purpose. Front lessons can't disappear early enough.


>you're forcing students to learn to engage with content online without someone spoon-feeding them.

How do you force them to engage with the content?


You don't!, forcing it, when the student isn't ready or doesn't care, is the source of students becoming numb to subjects and in some cases hate it for the rest of their lives without ever understanding them


If you don't need to teach non-interested students the material, then the job becomes a thousand times easier.


Exactly!. Is there any evidence that forcing content increases long-term life success to students?, Or is there at least some study on-going?

Schools have many impact vectors, forcing content learning is just one of them, and not necessarily a good one, I'm biased into thinking it's actually bad but it's overcompensated by its side-effects: place of gathering, exposure to higher-than-average smart people (teachers), introductions to some branch of knowledge, etc, and of course, forced-content consuming from interested students that probably would get better results from a self-paced learning system like Khan-Academy


>>You're skipping the often difficult task of getting the students to properly engage with khan academy.

As someone who is very much in favour of online education, this is still a pretty big unanswered question.

My response to that would be to ask to what extent this is being done in the classroom. Much like in the workplace prior to covid, people mistake physical presence for actually doing work. And if the classroom is then replaced with online learning with the ability to play back lessons and study at your own pace, how do you define "engagement"?


Word. I volunteered regularly in my son's classroom, K thru 6. Whatever ninja skills the gifted teachers have, I don't have it. The ability to command and direct the attention of dozens of young minds is a fusion of symphony conductor, improv comedy, and jedi mind control.

Rant: Any one thinking it's easy to teach should try it sometime. I get especially fluffed up by would be reformers who've never taught. eg Gates Foundation. While I appreciate the interest, deploy all y'all whackadoodle ideas against your own kids before torturing the rest of us.

Source: Mom was a special ed teacher for 20 years. Incredible how many people knew so much more about how to do her job than herself.


>I volunteered regularly in my son's classroom, K thru 6. Whatever ninja skills the gifted teachers have, I don't have it.

That makes two of us.

Some of my students referred to it as The Power.


Yet many kids have no problem learning a lot of things by pulling stuff they check online. Lets not pretend all kids are alike.


> For many kids, the quality of education they receive is a function of the quality of the school and the quality of the teacher.

I would agree if you strengthened this to "for almost all kids..."

Effective primary education is greatly dependent on the bond between the students and the teachers (IMO). Yes, you can learn your times tables from an online lecture and online drill program, but you can't replace elementary school with it. Secondary education likely has less of this property, but still way, way above zero.

There is no singular "best" teacher of a subject. There might be one who is best for many learners, but I believe a large element of education is finding exactly the student's "frontier" and repeatedly crossing it, slowly expanding that frontier while spending enough time inside for reinforcement, confidence-building, and repeated checking that you're right about the frontier.

It's heavily labor intensive and personalized, which is why it's local and why it's school and teacher dependent.


It's a lot harder to be mentored and inspired by a Youtube video than a good teacher who cares, even if you only have one of those teachers per year.


The demand for “good” teachers far exceeds the supply.


No, it's not a supply problem, it's a government subsidy distorting the market problem.

Get rid of government subsidies for education and let people choose what education they get, where and when. You'll quickly find plenty of willing, able and capable teachers.

While we're at it, get rid of minimum wage laws so that people who don't want to pay to learn, can do apprenticeship programs and instead get rewarded for their efforts.


I've been inspired by fitness instructors doing workouts dvd and I still think fondly of them while I can't remember any of my high school professors.

I see a lot of people going crazy after YouTube content creators so I'm sure it's viable for education as well.


I can't remember a single person I've watched on youtube educationally. I hate it - it's too easy to get distracted. When I'm in class, I can focus. On my computer I'll end up somewhere else and right quick.


That's pretty much what https://www.modulo.app/ provides. Small groups online (1-5 kids) with each kid doing apps/videos at their own pace, and getting help from the tutor as needed. Works great for our daughter. She's made a lot of friends thru it and accelerated academically a huge amount.

(I have no financial interest - just a customer.)


Most kids don't have adequate space or computers for this. They also need the school lunch. Most parents work during school hours.


Good timing considering that Khan Academy will be taking their MCAT prep offline later this year. [1]

Apparently another org will be hosting them through the end of 2021.

1: https://www.khanacademy.org/test-prep/mcat


Due to popular demand, the Khan Academy test-prep materials have been archived in the Kolibri Channel called "Khan Academy - Standardized Test Preparation" see https://kolibri-catalog-en.learningequality.org/en/learn/#/t...

If you want to continue accessing these, check out the instructions about setting up Kolibri posted in the thread above, then in step 3 download this channel using the token "nojon-baraz" or simply select from list. Once you download to localhost (might take a while), you'll have all the videos and exercises locally so not a problem even if this materials are taken down from the KA website.


That link does not show the instructions? Is it correct?


Sorry I didn't explain too well. That link is to an online demo server of the Kolibri app that has that channel imported.

You can get the same channel locally (localhost; for offline use) using the following steps:

1. Download Kolibri https://learningequality.org/download/ , 2. Install and start, 3. Go to Device > Content > IMPORT and choose the channel called "Khan Academy - Standardized Test Preparation" from the list, 4. wait for import process to finish, then you're done.

I posted the same info in another comment on this thread of this story so I didn't want to repeat here. See that for more info.


What was their justification for this? Even if they want to focus on high / middle school level content, I assume MCAT content doesn’t go stale quickly so they wouldn’t have to spend resources keeping it up to date.


It's also you need a team (or a PM or two w/ the ability to pull tech resources) of people that are focused on MCAT. Anytime you just leave something static as an org it will rot away in usefulness very quickly.


So just hide it, and put up a warning message at the top that the course is no longer updated. Why do they need to take it down? It won't consume bandwidth unless people actually use it (in which case, they must find it useful), and I can't imagine raw disk space is a concern. Or, if it is, throw up a torrent so at least people can grab the data.


That said the script doesn't seem to work for this course, for me - it downloads sections 0 and 4 then terminates. Anyone else having this issue?


Almost everything worthwhile I stumble upon gets archived to my private ArchiveBox instance these days. Sadly, there are a few Coursera/EdX courses that have been taken down (eg https://www.edx.org/course/engineering-the-space-shuttle) and coursera-dl/edx-dl seems to be broken OOB these days...


Mind to share how do you build your Archivebox?


As @jbc1 said, it's a name of a given software https://archivebox.io/. My only extra recommendation is to enable swap limiting at the kernel level as shown in https://docs.docker.com/engine/install/linux-postinstall/#yo... to prevent headless Chromium from using it all up.


There's https://ArchiveBox.io, but also lots of other great alternatives that work similarly: https://github.com/ArchiveBox/ArchiveBox/wiki/Web-Archiving-...


There's software called ArchiveBox, it's not a thing they made up. Or are you aware and you were asking how to use it?


Is this the kind of thing that can be added to youtube-dl? Are they pretty open to adding new sites?


Yeah, despite the outdated name, youtube-dl supports thousands of websites, and it seems like it already supports Khan Academy:

https://ytdl-org.github.io/youtube-dl/supportedsites.html


From the description up top:

"A python script to download courses from Khan Academy using youtube-dl and beautifulsoup4."


khan-dl uses youtubr-dl under the hood

Check the readme or requirements.txt


What does it add on top of youtube-dl then? Different naming?


The distinguishing feature is:

"You can download courses interactively on a prompt, which will list all course domains and their respective courses available with tab completion."


Ouff, as someone who has done my fair share of downloading Khan Academy content, this will be a lot of work. There are something like 20K+ videos, so downloading each of them will take forever (think weeks). You might get your IP blocked by youtube in the process, and in general, getting the HTML for each page will put unnecessary strain on the Khan Academy web servers, especially in this moment of hightened need.

Instead of downloading from scratch, I would recommend using one of the pre-downloaded and pre-packaged Khan Academy video archives: a Kolibri channel or a Kiwix ZIM file. Details provided below:

## Kolibri

This is the best open source offline learning app developed by Learning Equality (the same people that made KA-Lite, see https://learningequality.org/ka-lite/map/)

1. Download Kolibri from https://learningequality.org/download/

2. Browse the list of Khan Academy channels to find the one you're interested in (there are 16 diffenret channels, for the different languages available from Khan Academy website) https://catalog.learningequality.org/#/public?keywords=khan

3. After installing and starting Kolibri (it's a web app that runs on localhost) go to DEVICE > CONTENT > and IMPORT the channel you selected in step 2. (Note download will take a while, like 8h+ because it will have to download 20k videos, exercises, and subtitles).

4. DONE! You have the entire Khan Academy collection in an easy-to-use fully offline learning management system. For bonus points you can create separate "coach" accounts as a parent and watch your kids progress.

## Kiwix

This is another powerful app developed initially for offline browsing of Wikipedia, but now extended to support many other sites. Kiwix is based on ZIM files, which are highly optimized compressed archives for web content.

1. Download Kiwix as app or desktop program https://www.kiwix.org/en/download/

2. Find the name of the Khan Academy ZIM file for your language and course, search for "khan-academy-" on this page https://wiki.kiwix.org/wiki/Content_in_all_languages

3. After installing Kiwix, import the right ZIM file (again it will take a while).

4. BAM! Now you have all the videos offline (exercises not supported in Kiwix, only the videos).

Between the two options, the Kolibri option would be my recommendation because you get all the exercises as well, not just the videos, but if you're looking just for videos, then Kiwix is faster.


^ all of the above is Open Source software, developed by non-profits. If you want to support, here the relevant donation pages and code repos:

- Learning Equality => https://learningequality.org/donate/ and https://github.com/learningequality

- Kiwix => https://www.kiwix.org/en/support/ and https://github.com/kiwix

- And of course the big papas https://www.khanacademy.org/donate who make all this great content available in the first place!


Paging /r/datahoarder


Nice! These sort of tools are immensely useful for learners with a spotty internet connection.


Is there a downloader for edX? I recently tried coursera-dl/edx-dl and it didn't work. When I last checked on it, they were looking for new maintainers ( https://github.com/coursera-dl/edx-dl/issues/587#issuecommen... ).


Is there not a download function built into the website? It's a non-profit, they really ought to make those clips available...


Thats not how non profits work. They still have bills and alternative methods for viewing may impede their ability to earn revenue.


They don't show ads do they? Or is most of their traffic via YouTube?


I bet it’s to reduce server load. If a user only sticks around for one or two sections then if everything was downloaded up front the later sections would be wasted bandwidth


Khan Academy videos are Creative Commons licensed, and Kolibri provides a way to download the videos wholesale. Our focus is on the whole learning experience (which includes exercises and articles, plus keeping track of skills that a student has mastered). We also put a lot of work into providing tools for teachers and coaches to help students.

Videos are one part of our work.


Could put up a torrent. I'd certainly seed that.


It's to keep control. Plenty of services have offered full downloads over the years and bandwidth is cheap. There's no reason for them not to offer them unless they're being greedy.


It seems kinda weird to me to portray them as greedy. Even if the root of this decision is because they want money, don't they need to fund the content somehow?

Khan Academy seems to have really raised the bar for this kind of content. I'm inclined to trust their decision on how to maintain quality and balance that with accessibility. Maybe I'm just naive?

At the same time, it does seem like having the content easily available offline could help people out. I wonder if they've ever explained their rationale?


Because my statement isn't necessarily about Khan Academy, but anyone hosting cloud-based video content.

Data wants to be free, as they say, and digital economies are a world of abundance where copying is free or nearly so. When a provider doesn't align with that they are imposing physical-world scarcity economics in a place where it doesn't belong.

It feels like people are trying to erase fundamental concepts like files or downloading, and instead offering a bullshit rental model where anything you can do on the net is at the pleasure of the content owner. It is disempowering to users as it changes them from masters of their domain to digital peons in CC's feudalistic kingdoms.

That is what I mean by 'greedy'. If you publish something online, it is out there for good. You cannot try to delete it and you cannot try to control it. You do not have a right to try to profit on the content itself because, again, data is free and no matter how much one might want to control data, ultimately they can't. DRM, ads, subscription gates -- these are all additional layers of crap that we have built to cage that data and prevent it from being freed.

It is a shame that we as a people cannot handle this world of abundance, and that the tools we use to navigate it grant us less and less control with every new DRM scheme or subscription service.

There are plenty of ways to monetize without locking down bits.


> It feels like people are trying to erase fundamental concepts like files or downloading, and instead offering a bullshit rental model where anything you can do on the net is at the pleasure of the content owner. It is disempowering to users as it changes them from masters of their domain to digital peons in CC's feudalistic kingdoms.

This is why I find it so disheartening that Khan Academy doesn't allow downloads natively. I understand the incentives for a provider like Youtube are overwhelmingly in favor of streaming-only, but an educational nonprofit like Khan Academy? If even they don't offer downloads, what hope is there?


You can download videos for offline viewing with the mobile apps. Khan Academy is not just for video viewing, though. We (I work at Khan) have articles and exercises, keep track of a student's mastery of the material, etc.


Thanks, that's good to hear! I still think there should be a way to download these videos as standard mp4's via a web browser. Users shouldn't have to rely on third party python scripts if at all possible.

The articles and exercises are of course also important pieces, but there's no reason to make the video portion less accessible than it could be.


If they do so, is there any risk of spiders/obsessive collectors downloading everything? It’s been a while since I ran downloads directly off my website, so I’m genuinely not sure if there are enough of either to significantly alter bandwidth requirements.


The College Board (maker of the SAT) is also a non-profit


Yes, but the College Board is evil in a way I perceive Khan Acedemy to not be.


Khan Academy is essentially built around preparing students for College Board exams such as the SAT and AP. The College Board is even one of Khan Academy's key supporters


Direct downloads would certainly help, but I understand their concerns.


I think they don't want to "dilute" their value proposition. They are selling to various sponsors the idea is that their platform is the key, but if downloaded videos can suffice, it's a different story. Every platform these days want to control user "journey".


What are their concerns?


if khan academy sold their courses on DVD I would probably buy about 35% of their collection


Or the whole collection at a 65% discount?


Hey there, FYI this doesn't work on non-traditional subjects i.e. LSAT. I created an issue on GH, and ideally would have rather opened a PR, but don't have time at the moment. Cool tool, thanks for putting this together.


Incoming DMCA takedown :D


javascript:location.href='https://9xbuddy.in/'+document.location.href;

BOOKMARK that can help you download videos from many web sites


[flagged]


Yes, they are "worth a shit" to the millions of students they have helped, because videos being "pedestrian" doesn't matter when all you need is someone who can explain what your teacher tried to cover in class.

They're not meant for people who already have a major in the subject — they're meant for students in the middle/high school range.


Absolutely. Personally, I am forever grateful to Sal for helping me overcome my fear of math in my late teens. I started from 1+1=2 and eventually got to Calculus and Linear Algebra (using KA and other resources). I particularly liked the randomized exercises on the site, and how it tracked your progress over time. It became kind of an obsession -- I thought, if I can learn math, I can do anything. I believe Sal's style of teaching had a lot to do with it.

There are tons of other people like me, and it makes me sad seeing such bitterness about a person who obviously brought a lot of good into the world.


I literally only got through calculus in college because of this one guy on YouTube:

https://youtube.com/playlist?list=PL58C7BA6C14FD8F48

He doesn’t give TED talks, he doesn’t have an organization, he doesn’t have a tech team, and he isn’t selling a narrative. Probably because he didn’t go to MIT, and Harvard, and wasn’t the brand that could go out and evangelize it. But Khan was, so his responsibility is much higher, and he mostly failed at it.

I believe in what that guy is doing. What Khan billed himself as was unfortunate and we needed to see a lot more from it. A glorified YouTube tutor. This thread might as well be a how-to on using YouTube-dl to download any number of auxiliary help videos on YouTube, not for our pristine Khan, savior of education.


I understand that Khan Academy isn’t a right fit for you. But to make personal comments on an individual because they aren’t a fit for you, is petty. I hope you find more people whom you believe in and write about them.


Such an odd criticism, I think. Khan started in 2006 with exactly that, online tutoring using YouTube. Is your criticism that he ever considered doing more? That he gave a TED talk?

Are you asking why Khan is now close to a household name while patrickJMT is not? There could be many reasons: Khan started 2-3 years earlier, Khan is (now, and for a while) a non-profit, arbitrary chance, etc.

Besides, PatrickJMT has 350mm views, has 200 patrons, and has published a book, _Calculus for Dummies_. He doesn't seem to be doing badly.


I found it really useful and anectodally so have many other people that I know. From this and your other comments I gather that you aren't a fan. That's okay - it's a free resource and no one is forced to use it.


They are incredibly valuable to myself a lots of students I know.

He never claimed to be savior of education - he is doing the same thing the other youtube guy you linked to - just at a bigger scale.


What would be more than “worth a shit” in comparison to Khan Academy? What process do you use to define the “worth”?


Platforms that should have integrated with k-12 schools by now.

It was a massive failure of the vision more or less.


Are you telling us that platforms that don’t integrate with K-12 schools (but are a complement to them) are failures?


I think at this point, yeah. We have the tech.


We also have the tech to have complementary resources. You and me don’t get to decide success or failure of an initiative based on mere existence of technology.

It seems you’re quite passionate about labelling success/failures from your individual lens.


FWIW, Khan Academy integrates with Google Classroom, supports login with Clever and offers tools for teachers and school districts.


The vision should be to replace K-12 schools, which have no accountability for unionized teachers and poor results compared to schools worldwide. We need school choice and decentralization, not propping up failing institutions.


Not sure your education is finished.




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