Sunday, April 7, 2013

Thoughts on Online Learning

When online learning became a reality for me with MIT OpenCourseware, I was excited. I could watch Gilbert Strang teach Linear Algebra for free and learn at my pace. So when Coursera and Udacity were launched I was as happy as the next guy, if not more. I work with Machine Learning at my job and it is extremely valuable to me that I can watch related videos online, for free, with the content taught by some of the most prominent researchers/practitioners in their respective areas.

But it doesn't seem to have worked out very well for me. And apparently not for a lot of other people either. Personally, I am back to reading books. With a year of Coursera/Udacity behind us, I am seeing articles, like these, discussing shortfalls. In this post, I want to discuss where these fell short for me.

To be clear this is an extremely subjective article discussing things from my point of view. One that is not called "What's wrong with online learning?".

What I find missing

My first two online courses were Linear Algebra by Gilbert Strang offered by MIT Open Courseware and Machine Learning taught by Andrew Ng offered by Stanford Engineering Everywhere.When I had initially started going through the material, I wasn't doing much beyond watching the lectures and occasionally scribbling notes. Although the courses filled me with an immediate sense of achievement, I realized that my ability to recall finer details later was essentially broken. In most cases, when coming across a concept elsewhere, I could relate to it at a high level - but to dwell on the workings was difficult, and I often had to go back to the videos for a quick revision.

At this point, other problems would crop up - videos are not text books that you remember the layouts of. That makes skimming and visually searching difficult. They don't have indexes that can facilitate quick look-ups. I would typically narrow down to a specific couple of videos (one - if lucky) and then rummage about with the playbar till I found what I was looking for. Not  to mention I needed a computer and my video lectures around for that. Thus, not only was I unable to recall specifics, but digging them out was no walk in the park either.

To fix this, I re-visited the lectures and prepared extensive notes this time. That worked out amazingly well for me - I remembered most of the stuff, and had a ready reference to consult (my notes).

Fig 1. Notes from Machine Learning

But these came at the cost of a huge amount of learning time - if a particular video lecture was an hour long, listening to it and making notes seemed to take roughly twice that time, assuming I took detailed notes, and not merely wrote down what I heard/saw but phrased it in my own words.

Given that I was never much of a note-taker in class, and still did well on most of my courses, I had to wonder - why is it different now? Here are a few things I missed in my online learning experience:
  1. Active participation in the learning - in classes, I could ask questions. Equally important - others could ask questions. All during the class. The opportunity to ask questions worked to my benefit in two significant ways:

    • It kept me engaged. At some level, it felt as if the class was collectively and organically working towards discovering something

    • It prevented technical debt. Usually that term is used in the context of software development, but I feel it is equally applicable here. One shoe doesn't fit all - so if the material prepared by the lecturer falls short in satisfying a student he can immediately ask a question to satisfy his information need. With video lectures, I had to make a note to Google up something later. You could pause the video and do that instantly. Or, you could let these pile up and attend to them later. Either way, that wasn't the best of experiences for me for subjects I really cared about.
  2. Learning in a class for the want of a better term, is an immersive experience. This helps recall and motivation. You remember more than just the content from the class - you remember people, places, a comment that made you laugh, etc. Sometimes, these help recall stuff better. You also see real people sitting next to you trying to be good at the same thing as you. If you want to discuss a specific concept with them, it is easier verbally than posting on a forum. There is collective motivation to learn and communication with peers is easy.
  3. If you want to go back to revising something you can refer to your notes, the lecturer's notes or the textbook the class is following. With video lectures this is tough.
In a nutshell, for online courses, I don't think the content registers too well because they don't do great on the first couple of fronts. And what doesn't register, should at least be easily searchable -  unfortunately, that doesn't happen either.

I mentioned I have moved back to text books. Why am I learning better with them? With regards to the first two factors I think textbooks actually do worse than online learning. But they do way better when it comes to ease of revisiting stuff - and that ease aids reinforcing of material which sort of makes up, over a period of time, for the relatively lacking engagement.

It hit me when I started taking the course on Probabilistic Graphical Models by Daphne Koller. The lectures were detailed -I loved them- but the need for taking detailed notes increased too. Given my full-time job it was becoming difficult - I was not sure how long I could keep up.

Fig 2. Notes from Probabilistic Graphical Models

One weekend I ended up with a sprained neck trying to take notes for a bunch of lectures.  I gave up, re-enrolled when the course was offered the next time, only to again drop out for similar reasons. The gamification (deadlines) made me feel stupid and was demotivating. I realized that this wasn't sustainable for me and went back to books.

To sum up the comparison, textbooks provide me with a medium I can easily revisit, and the time I am not spending creating this easily searcheable medium - which I would have to for video lectures i.e. take extensive notes - makes up for the other benefits video lectures have to offer.

Possible solutions

To be frank, I don't know what changes would make online courses better for me. It's hard to know without actually trying. Personally, I should probably focus on only one course at a time and accept the fact that it is going to take me much more than the stipulated time to finish it.

However, if I were to take guesses as to what might make courses better, this would be my list:
  1. Make lectures more interactive - this would promote engagement. Interaction in courses exist - the operative word is "more". Better engagement would help better recall and drive down the need for extensive note taking. Note that this does not completely do away with the need for taking notes - but only eliminates the need to do it in painstakingly copious amounts.

    Interaction is one way to promote engagement. There might be others too. Perhaps, something on the lines of what the Head First guys did for programming? They made reading programming books as easy as reading story books. Is there a way to make watching video lectures as effortless as watching a movie? Or, playing a game - like this experiment from UCSD.
  2. Make them searchable - somehow. Find a way so I can revisit the course for specific topics with ease. Transcribe the speech of the lecturer and index the video timeline with words from the transcription if that's what it takes!
  3. I like how Erik Demaine prepares his courses.

    Fig 3. Geometric Folding Algorithms by Erik Demaine

    Fig 3. is from his course on Geometric Folding Algorithms. There is a lecture video on the page, there is a frame with handwritten notes in it (shown in a black box) and there is another frame with slides in it (shown in a red box). The video, the notes and the slides are synchronized: when Erik moves ahead with  his lecture, the slides and notes change pages too.

    This helps the learner associate textual content - notes/slides - that can be searched (probably easier after printing) with the actual lectures. This is a clever way of maintaining the engagement videos give us, and making the content easy to revisit later without actually revisiting the video. All depends on how strong you can make the association between the text content and the video in the presentation.

    InfoQ and do this to some extent too.