

Why are lectures more detailed than texts? - Eliezer
http://lesswrong.com/lw/121/media_bias/

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ianbishop
Some reasons I could think of, off the top of my head..

* Doing a lecture series only takes as long as it takes to film. There is no post-lecture work, such as rigorous editing or re-organization of ideas.

* You can rant. As long as you are speaking and guiding the listener along with you, you can easily make reference to things that are explained later on or go on tangents. If you are publishing an article and go off topic, people might skip it sections all together or become confused by the switch as they only skim text.

* Publishing a piece of text in your name is a bigger deal than posting a video.

~~~
cduan
A few more:

* Lectures let you see how well your audience is getting it (assuming you're lecturing to an audience). So you can tell what's making sense and what's not.

* You can talk faster than you can write. In fact, in my experience, I can talk about as fast as I can think. I can't write as fast as I think. This makes me inclined to skip over some thoughts while I'm writing, simply to keep up.

Incidentally, I don't see why the first point ("There is no post-lecture work,
such as rigorous editing or re-organization of ideas") is really an advantage
of lectures. Certainly there are many lectures I've seen that could have used
some reorganization. And, at any rate, any decent lecturer will do preparation
beforehand to organize the presentation.

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apu
While not applicable to other areas, I know that conference papers in CS (and
many journal articles as well) have stringent page limits. Thus, given a short
amount of space, you have to prioritize what goes in the paper.

Secondly, when writing an academic paper, the primary goal is to keep the
reader/reviewer interested. That is why proofs, simple calculations, and other
such "trivial matters" are relegated to appendices -- the flow of the main
paper should not be disrupted by these.

Finally, one advantage to omitting steps is to ensure that the reader is
putting in effort to understand the concepts. Fully drawn-out text would
invite people to do conceptual "copy-paste," which would cause problems when
they try to apply their knowledge to real-world problems. An analogue of this
phenomenon is seen on the web with php programmers, who frequently copy-paste
php code found from various tutorials without really understanding what's
going on.

However, for in-depth tutorials published online, I agree with the author that
super-detailed texts are best. And here, the practical issue of the time spent
by the author typing, checking, and revising the tutorial starts to become the
dominant reason why tutorials aren't so detailed -- at some point, it's simply
not worth the author's time.

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mpk
Verbal communication is just inherently different from communication through
the written word.

We've all encountered teachers who lecture "as though they are reading from
the textbook". It's the same information, so why should it matter?

I think it has to do with verbal communication being more about interacting
with other people. When I see another person lecturing (live or through
video), I find it easier to stay focused on what they are telling me. There
are all these visual cues that add some extra hooks. And then, of course, the
verbal ones. The accents, the pauses, the little jokes or references that are
thrown in.

Just think of your favorite stand-up comedian. Compare reading a transcript of
your favorite session to an audio recording of that same session to a video of
that exact same session. You probably experience them all very differently.

So instead of comparing a text with a lecture, where both share the same
subject matter, compare a text of the lecture with a video of the lecture.
(Bonus points for comparing a text on paper with a video of some guy reading
that paper aloud).

~~~
tjr
<http://video.google.com/videoplay?docid=-8860158196198824415>

[http://homepages.inf.ed.ac.uk/wadler/documents/steele-
oopsla...](http://homepages.inf.ed.ac.uk/wadler/documents/steele-oopsla98.pdf)

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naveensundar
I think lectures are better/detailed due to feedback from the audience. The
lecturer can guess when to go fast and when to go slow(and explain more) by
gauging the audience. In some cases the author of a book can guess what his
audience can think and provide explanations in advance. But thinking what your
reader might think is hard. I feel in the case of the author of the article it
was just an accident that he is very similar to the audience that was present
during the video lecture.

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Herring
> _It's especially bad in math, in which writers have a long tradition of
> deliberately concealing difficult steps and leaving them "as an exercise to
> the reader"._

You're supposed to do those exercises. If you're a programmer think of them as
unit tests. In technical subjects, most of the information is contained in the
problem sets. For that reason I'd actually say the texts are more informative
- more detailed.

~~~
krzyk
Yeah, it's ok when you know the answer (e.g. when you have to provide a proof
of some theorem), but when you have a excercise section at the end of the
chapter some books do not provide answers to those excercises. It's like
having unit tests without knowing if the correct solution is e.g. 2 or 5.

~~~
Herring
I'd say I almost always get 70%+ of the benefit just by having an answer. And
there's other techniques that help, eg checking one problem against other
problems, getting a bound on your error, asking on forums/mailing lists, etc.

