CS 231n: Convolutional Neural Networks for Visual Recognition is, in my biased opinion, one of the most important and thrilling courses offered by Stanford University. It has been taught twice so far and will appear again in the upcoming Spring quarter.

Due to its popularity, the course lectures for the second edition (Winter 2016) were videotaped and released online. This is not unusual among computer science graduate level courses due to high demand both inside and outside the university.

Unfortunately, as discussed in this rather large reddit discussion thread, Andrej Karpathy (one of the three instructors) was forced to pull down the lecture videos. He later clarified on his Twitter account that the reason had to do with the lack of captioning/subtitles in the lecture videos, which relates to a news topic I blogged about just over two years ago.

If you browse the reddit thread, you will see quite a lot of unhappy students. I just joined reddit and I was hoping to make a comment there, but reddit disables posting after six months. And after thinking about it, I thought it would make more sense to write some brief thoughts here instead.

To start, I should state upfront that I have no idea what happened beyond the stuff we can all read online. I don’t know who made the complaint, what the course staff did, etc.

Here’s my stance regarding class policies on watching videos:

If a class requires watching videos for whatever reason, then that video should have subtitles. Otherwise, no such action is necessary, though the course staff should attempt as much as is reasonable to have subtitles for all videos.

I remember two times when I had to face this problem of watching a non-subtitled video as a homework assignment: in an introductory Women’s, Gender, and Sexuality Studies course and an Africana Studies class about black athletes. For the former, we were assigned to watch a video about a transgender couple, and for the latter, the video was about black golfers. In both cases, the professors gave me copies of the movie (other students didn’t get these) and I watched one in a room myself with the volume cranked up and the other one with another person who told me what was happening.

Is that ideal? Well, no. To (new) readers of this blog, welcome to the story of my life!

More seriously, was I supposed to do something about it? The professors didn’t make the videos, which were a tiny portion of the overall courses. I didn’t want to get all up in arms about this, so in both cases, I brought it up with them and they understood my situation (and apologized).

Admittedly, my brief stance above is incomplete and belies a vast gray area. What if students are given the option of doing one of two “required” assignments: watching a video or reading a book? That’s a gray area, though I would personally lean that towards “required viewing” and thus “required subtitles.”

Class lecture videos also fall in a gray area. They are not required viewing, because students should attend lectures in person. Unfortunately, the lack of subtitles for these videos definitely puts deaf and hard of hearing students like myself at a disadvantage. I’ve lost count of the amount of lectures that I wish I could have re-watched, but it extraordinarily difficult for me to do so for non-subtitled videos.

Ultimately, however, as long as I can attend lectures and understand some of the material, I do not worry about whether lecture videos have subtitles. Just about every videotaped class that I have taken did not have subtitled lecture videos, with one exception: CS 267 from Spring 2016, after I had negotiated about it with Berkeley’s DSP.

Heck, the CS 294-129 class which I TA-ed for last semester — which is based on CS 231n! — had lecture videos. Were there captions? Nope.

Am I frustrated? Yes, but it’s understandable frustration due to the cost of adding subtitles. As a similar example, I’m frustrated at the identity politics practiced by the Democratic party, but it’s understandable frustration due to what political science instructs us to do, which is why I’m not planning to jump ship to another party.

Thus in my case, if I were a student in CS 231n, I would not be inclined to pressure the staff to pull the videos down. Again, this comes with the obvious caveat; I don’t know the situation and it might have been worse than I imagine.

As this discussion would imply, I don’t like pulling down lecture videos as “collateral damage”.1 I worry, however, if that’s in part because I’m too timid. Hypothetically and broadly speaking, if I have to take out my frustration (e.g. with lawsuits) on certain things, I don’t want to do this for something like lecture videos, which would make a number of folks angry at me, whether or not they openly express it.

On a more positive note … it turns out that, actually, the CS 231n lecture videos are online! I’m not sure why, but I’m happy. Using YouTube’s automatic captions, I watched one of the lectures and finally understood a concept that was critical and essential for me to know when I was writing my latest technical blog post.

Moreover, the automatic captions are getting better and better each year. They work pretty well on Andrej, who has a slight accent (Russian?). I dislike attending research talks if I don’t understand what’s going on, but given that so many are videotaped these days, whether at Berkeley or at conferences, maybe watching them offline is finally becoming a viable alternative.

  1. In another case where lecture videos had to be removed, consider MIT’s Open Courseware and Professor Walter Lewin’s famous physics lectures. MIT removed the videos after it was found that Lewin had sexually harassed some of his students. Lewin’s harassment disgusted me, but I respectfully disagreed with MIT’s position about removing his videos, siding with then-MIT professor Scott Aaronson. In an infamous blog post, Professor Aaronson explained why he opposed the removal of the videos, which subsequently caused him to be the subject of a hate-rage/attack. Consequently, I am now a permanent reader of his blog.