I've watched the first few PGM lectures from Open Classroom. I noticed that the way things are presented there is less compelling than in the AI course. This has nothing to do with Daphne Koller's teaching as I'm enjoying that so far. Rather it has to do with the format of the course and the way that text appears.

There are two primary images in the PGM lectures (1-4). First, a headshot of the instructor in the lower left-hand corner (web-cam quality) with the other three quarters of the screen used for text. Second the "magical appearance" of text on the full screen. The second one matches the way that text appears in Khan Academy lessons except that it's black-on-white instead of many-colors-on-black.

In the AI lectures the two primary images were full-screen headshots - Sebastian or Peter talking directly to the camera (and so to me/you) and writing on paper with a human hand and a pen viewed from behind the writer.

I think the AI version is better and more personal. The PGM model has me looking at a computer monitor with an invisible someone writing text from behind the screen. The AI model has a human writing in ink on a piece of paper in front of me. This is much the same feeling you get when trying to explain something to friend in a bar or restaurant. You grab a (paper) napkin and start drawing/writing.

I thought of the AI teachers as Peter and Sebastian almost immediately. It seems unlikely that I'll think of the PGM teacher as Daphne unless the lecture model is different.

Your thoughts?

asked 03 Feb '12, 10:31

robrambusch's gravatar image

robrambusch ♦

@robrambusch ♦ Could you please post the link for the open classroom PGM class? I only know of http://openclassroom.stanford.edu/MainFolder/HomePage.php but PGM isn't listed there.
(03 Feb '12, 13:40) octon octon's gravatar image

I prefer the writing without the hand in the way, blocking the text. I like to be able to read what is written especially when I need to pause the video to take notes. That was difficult with AI and the short videos were also a problem with this as they had often gone on to the next one before I had a chance to pause. The short videos didn't flow at all for me in AI. What might also affect my view is that I much prefer the precise style of Profs Koller, Widom and Ng than the more 'guess what I mean' style of the AI course.

I do prefer the version for DB where you can see Prof Widom the whole time rather than just the writing. I like to see the face of the person I am hearing. I never found the full screen face in AI personal, but rather too much 'in my face' and overbearing. I don't find news readers personal so I'm not quite sure why a face on a screen would be personal. Personal to me is being able to speak to someone and get a response, not just watch them doing something without interaction.

I suppose we each have our preferences and there is no way everyone is going to be happy with one method over another.


answered 03 Feb '12, 12:57

fnenu's gravatar image


I agree. I guess it also depends on the size of one's monitor how much face one is comfortable with. And broadcast wasn't made for "personal". I don't have a personal relation with the professors and I don't need to pretend I do.
(03 Feb '12, 14:10) lacucharita ♦ lacucharita's gravatar image

I got spoiled in AI-Class by the way one of the instructors would start writing something and then the video skips ahead to the point where they've finished and all the text is on the screen. Having to watch Prof. Koller actually write the whole thing seems to take awhile after that!


answered 03 Feb '12, 13:09

Jason%20Barrett's gravatar image

Jason Barrett

I've noticed the same thing. But what I'm missing more is the chance to stop and practice what I've just learned. Of course, I can and do stop the video, but I'd love to have little problems queued up for me. In the real course, I expect we'll have some problems.
(04 Feb '12, 02:08) Anne Paulson Anne%20Paulson's gravatar image
I liked this kind of skip most of the times, but sometimes I had to press the pause button to actually follow the formula written. I'm not sure if they used some kind of software which automatically fades over the parts with an audio break, or maybe did it manually. ML class had those 1.2x and 1.5x speed buttons, which also had some advantages, especially when reviewing a video for the second time or speeding up a topic your familiar with. I guess the final Coursera classes will have those buttons again.
(04 Feb '12, 07:08) rhasarub rhasarub's gravatar image

I've found each of the new classes slightly jarring, but I don't think it is the format. I also recall finding Peter Norvig's first few videos jarring. I think this is why Librivox recommends recorders redo the first section after the end so you are completely at home.

The ML and DB classes were in the coursera format like PGM and I thought they were just as engaging as AI. When you spend a few hours talking to yourself in an office I think your personality has to shine through.

If we were constructing controlled experiments, I would actually propose the videos primary benefit is in being engaging/mandatory enough to prevent other visual distractions from stealing attention from the speaker.


answered 03 Feb '12, 11:27

lossleader's gravatar image


It may just be a prejudice on my part in favor of full-sized people and paper over webcams and cursors as I've spent much more time interacting in the former arena.
(03 Feb '12, 11:45) robrambusch ♦ robrambusch's gravatar image

I'm more to the side of @robrambusch "feelings", I'll try to explain my point congruently, hopping to be succesfull.
Having taken both DB and AI classes, I sow that my "overall income" was grater from AI than from DB. I think the reason is that as DB was aimed almost only to your intellect, i.e mostly to one side of your brain, with only weekly chats aimed also to "your feelings" (the other side of your brain), AI class reached (intentionally or not) both sides of your brain during the classes, there was a high intellectual challenge and also were involved "strong" feelings (as we can see from the posts here and in reddit) that triggered, subconsciously, a second/complementary type of "glue" or "absorption agent" for fixing the knowledge.


answered 03 Feb '12, 23:39

jimgb's gravatar image

jimgb ♦

For me the flow of "concepts" in ML and now also (after doing 5 videos) in PGM were much more cohesive and absorbable over the 8-12 minute uninterrupted videos than the 1 to 2 minute ones of AI, interrupted with quizzes. The separated review questions in ML also meant you could absorb the whole topic and then do the questions, submit them and get immediate feedback on where you went wrong (say 3.75/5.00). You could then go back to the topics, make sure you understood and try the review questions again. But here's the rider - the questions in each attempt would be different, so you might even get less marks in the second attempt! This means that you are really motivated to get 5.00/5.00 and by the time you do after perhaps 3 attempts, you REALLY understand the topic. I found by the end of the course I was making every effort to absorb the videos so I could get 5.00/5.00 first time round. The homework programming assignments were similar with online submission and immediate feedback and resubmission. By the time you got 100% for the homework, you pretty much understood how to implement the algorithms. Here's hoping the actual Coursera PGM course adopts the same review question and homework assignment processes!


answered 04 Feb '12, 00:19

adrcuth's gravatar image


I just watched the first video of PGM from OpenClassroom, and I'm hesitant to make any judgement based just on one video, since it took me a while to warm up to Peter and Sebastian.

But I will say this:

Ban Comic Sans!


answered 03 Feb '12, 17:12

L_McLean's gravatar image

L_McLean ♦

Haha, agreed.
(04 Feb '12, 07:13) rhasarub rhasarub's gravatar image

Speeding up the ML videos made them less engaging but more convenient. We had a choice of 1.0x, 1.2x, or 1.5x.

I ended up preferring ML's format over AI's, but that was more a matter of attitude than the interface. So I'd be happy with either format, as long as hands don't cover up the writing too often.


answered 04 Feb '12, 00:28

EllenL's gravatar image


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