Link of the day: Khan's Academy

Lately, I've tired of TED talks. They were bold and exciting when they first appeared online (3-5 years ago?), but now people just seem to be selling their ideas whether they are merely good or truly brilliant. It's important to have inspirational meetings, but I think they should also be authentic and realistic.

There is one recent TED talk that I do like very much. Salman Khan, a former hedge fund analyst, spoke about how video can re-invent education. Originally, Khan recorded videos to help tutor his cousins in math. He posted the videos on YouTube and left them publicly available, in case someone else might find them useful. His cousins told him that they preferred their "virtual" cousin on video than the real thing! They found the video less intimidating because they could stop and repeat it without appearing stupid; they could learn at their own pace.  Other people discovered Khan's videos and gave him so much positive feedback that he quit his finance job and started producing videos all the time. (Khan does all the math and science videos, and he hired experts to do the videos on humanities subjects.  The scope of this project is astounding: 2000+ videos.)

That alone would have been an outstanding accomplishment, but Khan didn't stop there.  He tried to track learning outcomes.  He associated each video with a particular concept and made tree diagrams showing which concepts were prerequisites for other concepts.  Khan calls this a "knowledge map."  Students can work on modules.  When they get enough problems from the module correct, they can move onto another module.  When they master the prequisite modules, they can move on to a more advanced module, and so on.

This systematic tracking of the student's progress is invaluable to a teacher in charge of 30 students.  The teacher can see how the class is doing.  Moreover, if a student is struggling with a particular module, the teacher can find another student who mastered it and have that student teach the other one.  Peer learning!  (I discussed this topic in an earlier post about a Harvard professor struggling to teach first-year physics.)  Now, at least one school district (in Los Altos, California) is trying out Khan's system in the classroom.

When the system was used in the classroom, it showed that different people find different concepts easy and different concepts hard.  In Khan's words:

Because every time we've done this, in every classroom we've done, over and over again, if you go five days into it, there's a group of kids who've raced ahead and there's a group of kids who are a little bit slower. And in a traditional model, if you did a snapshot assessment, you say, "These are the gifted kids, these are the slow kids. Maybe they should be tracked differently. Maybe we should put them in different classes." But when you let every student work at their own pace -- and we see it over and over and over again -- you see students who took a little bit extra time on one concept or the other, but once they get through that concept, they just race ahead. And so the same kids that you thought were slow six weeks ago, you now would think are gifted. And we're seeing it over and over and over again. And it makes you really wonder how much all of the labels maybe a lot of us have benefitted from were really just due to a coincidence of time.

I found this very interesting.  I'm guessing that a lot of teachers and coaches know that student learning is much more complicated than "gifted" and not gifted.  It's nice that Khan can actually provide hard evidence establishing this fact.

Khan's work is amazing and inspiring. I do have a few questions. Using technology to tailor education is not a new idea. Why did Khan succeed? Is it because students are more comfortable with technology compared to students of the past? Why is video better than a textbook? A textbook is also non-intimidating and self-paced.  Maybe it's because Khan is a great tutor who is both a talented teacher and entertainer?  (I briefly viewed one of his videos and he seemed funny and charismatic.)  In an ideal world, each student would have a one-on-one tutor.  This isn't realistic.  However, if we have a great tutor like Khan and he makes free videos available to anyone on almost every possible math and science topic from kindergarten to high school, this tutoring database is a pretty good, though imperfect solution.  It's reminiscent of an idea in artificial intelligence.  You can have a computer that isn't smart in the human sense, but if you program it with an astronomical amount of information, it can be very useful.

I think that doing online homework is becoming more popular as teachers realize that there is simply not enough time in the classroom to do everything.  There are a lot of things students can do on their own with a "computerized" tutor.  By "outsourcing" this teaching and doing it outside the classroom, the human teacher has more time to teach things that are hard for computers.  Like having students discuss problems together.  Or showing how many seemingly disparate concepts unify into a larger concept.  Or doing hands-on science experiments.  I know that for first-year physics courses, some universities assign online homework several times a week.  This forces students to read the book and work on problems at home so that the lecturer can spend time explaining concepts rather than writing 20 equations on the blackboard.

What Salman Khan is doing is incredible work and I wish him the very best.

HD dSLR video vs traditional 35mm film

HD dSLR video is all the rage nowadays. But I'm a still shooter and know very little about "motion." I should discuss some terminology and technical issues that relate to motion pictures, but that we don't worry about in still photography. First, video refers to shooting without film (no rolls of film that need to be processed in a chemical lab. Second, you do not use auto-focus for shooting motion pictures. Hollywood studios employ "focus-pullers." Their job is to manually focus the camera at all times, so that the appropriate scenery/actor is in focus. People and things move around, so this is not an easy job.

I learned about the differences between HD dSLR and 35mm film from two sources: Ken Rockwell who used to work in Hollywood before focusing on digital photography and an interview with Greg Yaitanes who recently directed the season finale of House. The episode was filmed entirely with the Canon 5D Mark II. They're coming from a professional, Hollywood studio perspective, but I think much of the discussion is still relevant to amateur filmmakers.

Pros of HD dSLR

• No film and processing to pay for (that same advantage that digital still cameras have over film still cameras) - this will save you tons of money. According to Ken Rockwell, an hour of film costs a Hollywood studio $10,000 - for the film itself and all the processing.
  
• Since HD dSLR is already digital, you can take advantage of an all-digital workflow. This can save you lots of time and money since you can do all your post-production with your own team of people, in-house. The same advantage that digital still cameras have over still film cameras.
  
• You can shoot at ISO 1600+ and do amazing low-light video, which is not possible on film.
  
• The dSLR is tiny compared to the 35mm film camera, so you can record video in very tight spaces and not have to remove walls in your set in order to film from different angles
  
• There are tons of fast lenses available already for still cameras. You can shoot with an f/1.2 lens and get amazingly shallow depth-of-field. Or better yet, use a macro lens! According to Greg Yaitanes, they shot the House episode mostly with the 50mm f/1.2 and 85mm f/1.2 Canon lenses, and they also used the 24-70mm f/2.8, 70-200mm f/2.8, and 100mm macro lenses somewhat. Yaitanes claimed that he could get depth-of-field on the Canon 5D Mark II that was one quarter smaller than film.
  
• Or heck, imagine shooting video with a tilt-shift lens or fisheye! So many creative possibilities open up when you can use still camera lenses.
  
• The dSLR full frame sensor (24mm x 36mm) is larger than the 35mm film frame (approximately 18mm by 22mm). APS-c sensors are comparable in size to film (approximately 16mm x 23mm). So you'll always get shallower depth-of-field with full frame dSLR sensors. This is the reason why Greg Yaitanes chose to use the full-frame Canon 5D Mark II over the APS-c Canon 7D and APS-H Canon 1D Mark IV.
  

Pros of 35mm film

• In general (at "normal" ISOs), film simply has better image quality than HD dSLR video. This is the big issue. Film has a much better response to highlights whereas CMOS/CCD sensors blow out highlights very easily. However, if you are very good at lighting, you can probably use HD dSLR video and get around it somewhat. As Ken Rockwell says, you cannot do HDR with HD dSLR video. At least not right now.
  
• Manual focus on HD dSLRs is very difficult. Since the exciting part of shooting with HD dSLR is the potential for super shallow depth-of-field, that makes focusing even more difficult. But this should change as camera manufacturers get feedback from film makers and they improve the technology. Zeiss recently came out with fast, manual-focus prime lenses, designed specifically for HD dSLR video.
  
• Hollywood studios have been working with film forever, so they know how to use it. HD dSLR video is a new technology and film crews have to learn how to use it.
  

Link of the day: Canon 7D + Lensbaby used to shoot Hollywood television

Awesome! I didn't know big-time Hollywood people were using the Canon 7D (+ the Lensbaby!) to shoot television. Read all about it in this post by Philip Bloom. Too bad I can't find the relevant clip from "Dollhouse" but according to the information in the post, I believe it is in the episode "Belonging."

Link of the day: Pamela Douglas on TV dramas

As part of my interest in television, I've been watching some nice, informative videos by USC professor Pamela Douglas. I stumbled across them while trying to figure out how much a TV drama episode costs (answer: $2-$5 million).

Douglas gives very clear and insightful explanations about history and trends in TV drama as well as the mechanics of writing, funding, and producing TV dramas.

Note: I just discovered that Videojug (the site hosting the Douglas videos) allows you to download the videos and also read a text transcript. Reading the text is much faster than watching the video.

Search beyond Google

I've recently realized that I use websites besides Google to search for information. The heavyweight is of course Wikipedia. I read an article (can't remember where) decrying the fact that Wikipedia articles now frequently come up as the number one search result on Google.

The New York Times finds that many people (especially children) use YouTube as a search engine. I certainly have done that, especially when my searches involve a strong visual element, for instance, an obscure sport. I like using Youtube to bookmark favorite video clips. Even if I own the DVD, it's nice to instantly pull up a favorite scene from a TV show. As someone remarked in a post (forgot where this one came from, too), we don't currently have a standard way to bookmark and highlight video the way we can with physical books and papers. It would also be wonderful to search YouTube videos in more complex ways than just by title, description, and tags. For example, what if I wanted to find all instances of pigs in Youtube?

A couple weeks ago, I mentioned how Midomi allows people to search for tunes. I also used Flickr to look for photos of New York Comic-Con. It's my first big comic convention and I wanted to know what to expect.

Link of the day: An anthropological introduction to YouTube

Professor Michael Wesch of Kansas State University does research on the YouTube phenomenon. He presents a summary of his findings in this hour long YouTube clip.

Amazing presentation! Fun, smart, poignant, insightful. I wasn't sure I wanted to spend an hour on this, but Michael Nielsen said it was great and I believed him. I thought it was pretty funny to learn about "first vlog" syndrome -- the feeling that you're talking to everyone and no one at the same time. It's very awkward and I felt the same when I made my first podcast.

I had no idea that YouTube was such a deep and diverse community, that the hardcore users care about each other. Is YouTube the solution to the "bowling alone" syndrome, to our modern age alienation as Professor Wesch seems to suggest?

Link of the day: Structure and Interpretation of Computer Programs video lectures

I was so psyched when I found out that my all-time favorite course had video lectures available for download! I took the fabled Structure and Interpretation of Computer Programs course (known as 6.001 to the students) as an undergraduate (though not with the creators of the course, Abelson and Sussman). I loved how we went through all the cool stuff in CS in just one course! We covered recursion, object oriented programming, compilers, streams, and of course lambda calculus (keep in mind that this was meant to be an introductory course). My favorite project was the object-oriented adventure game.

Link of the day: Inbox Zero

Merlin Mann gave a talk at Google about getting your email to inbox zero. Nothing really new here, but it is a nice presentation and a very good introduction to email processing such that you could send it to your mom or co-worker.

Reversible fluids

I found a really cool video showing "hydrodynamic reversibility" in a low-Reynolds number fluid. Didn't they teach us in statistical mechanics that the world is on an irreversible time trajectory? Well, not in this case. Check out the video by clicking the link under Figure 1. The film was apparently made by G. I. Taylor.

Link of the day: "What I Wish I Knew When I Was 20"

Tina Seelig, Executive Director for the Stanford Technology Ventures Program, gave a nice graduation-type talk called "What I Wish I Knew When I was 20." It seems like a collection of practical, well-thought out advice. Here's her list of top 10 things that a 20-year old ought to know:

• Every problem is an opportunity for a creative solution
  
• The harder I work, the luckier I get (work prepares you for opportunities)
  
• Find the intersection between your passion, skills, and the market (as opposed to the tired old adage "Follow your passion")
  
• Try lots of things and keep what works (try writing a "failure" resume)
  
• Don't wait to be anointed. Just do it!
  
• It is a very small world... don't burn bridges (you keep running into the same people, so don't make them hate you)
  
• You can do it all, just not at the same time (examine your priorities over a long time scale)
  
• It is the little things that matter most (e.g. thank you notes)
  
• It really is about the team (making other people successful makes you even more successful)
  
• Never miss an opportunity to be fabulous.

Her talk is available in several formats: mp3, slides in pdf, and steaming Windows Media video file.

Link of the day: Colloqium talk on community-based data management

I learned about a really interesting talk via Dave Bacon's blog. Here Raghu Ramakrishman talks about the emergence of social websites (e.g. flickr, del.icio.us, etc) and how the future of the web may lie in leveraging community input to improve data extraction. In the beginning, we had the web which was just static text and pictures. Then Alta Vista and other search engines used anchor text to improve searching. After that, Google came up with the concept of page rank. By looking at the many levels of linkage and giving more reputable sources a higher weight, you can come up with the most relevant search result. The next step in the evolution of the web may be using the direct input of users (e.g. tags) to improve data extraction.

Ramakrishman has been doing research on a very small-scale example called DBLife. It is a site that tries to extract data about academic researchers in the field of databases. If you search for a particular researcher, DBLife will attempt to generate pictures of the researchers, his/her list of publications and talks, and other information. You (the user) can then submit input on whether you think the information is accurate. So Ramakrishman's great hope is that we can develop software that is easily maintained by a community of users, that it will be easy to abstract the underlying structure of DBLife and apply it to other communities like Hollywood (e.g. HollywoodLife). In other words, one could give the software to another community without them having to look at any code.

The video of the talk is available here.

Link of the day: "When is a Googol not enough?"

Wati Taylor (an MIT string theorist) gave an awesome talk at Google about why there may be as many as 10^1000 possible solutions to describe the physical universe and how it might be possible to narrow down the possibilities using search algorithms. I really like how his talk is straightforward, clear, and concise. It's neat how string theory, cosmology, and algorithms come together in this problem.

NHL Google Video

At long last, you can watch NHL games on the internet via Google Video! The NHL posted this press release on their webpage today.

Link of the day: Imagining the Tenth Dimension

I have a hard time taking string theory seriously because it's so hard to imagine more than three dimensions. But now I can visualize higher dimensions much better, thanks to a flash tutorial at the site appropriately called "Imagining the Tenth Dimension." Click on the sidebar link labelled "Imagining the Ten Dimensions".

"Amateur" radio

I went to a ham radio club meeting today out of curiosity. At the end of the meeting, we watched a clip from the Jay Leno Show. Mr. Leno pitted two teenage text messagers (supposedly the fastest in the US) against two ham radio operators using Morse code (30-40 years of experience). The competition was to see who could send a message faster. A woman in the audience bet on the text messagers, but the Morse coders won. As Jay Leno said to the text messaging teens, "Sorry, you were beaten by 170-year-old technology."

I learned, on a more serious note, that ham radio (so-called "amateur" radio since individuals, not corporations, are the operators) has vital uses in remote areas and during disasters. In an emergency, cell phones and landlines are often jammed and the only reliable method of communication is through ham radio. Sometimes when several different emergency response teams work together (fire, police, ambulance, etc.), they solicit the help of ham radio operators to communicate between the different teams. The reason is that each team uses its own unique frequency so they need ham radio operators to set up a universal communication system.

Amateur radio operators have also campaigned against BPL (Broadband over Power Line). BPL is the idea that you can transmit broadband internet signals over power lines in RF (radio frequency). It seems like a great idea to bring broadband to rural areas, but the preliminary technology interfered with much of the RF spectrum including fire, police, and ham radio frequencies. The ARRL (American Radio Relay League) convinced the FCC (Federal Communications Commision) to ensure the protection of the RF frequency band in areas where BPL might be deployed.

Link of the day: cochlear implants

There's a great video of a Fermilab colloquium about cochlear implants. The talk was given by Ian Shipsey, who uses a cochlear implant himself.

It's really cool that Fermilab tapes all their colloquium talks. I wish other universities would do the same. Sure, there are books and papers out there, but nothing beats the experience of listening to another human being tell you something!