[metalman]

having spent significant time with people who hold spoken knowledge, I can promise you that there are still many things that can only be passed this way, and an ancient comment, passed verbaly to me, is directly relevant, as it concerns the adoption of writing by an affiliated tribal group, and how this was proof that "their minds are weak"

[harvey9]

If you video the speaker and I watch the video, what knowledge do you learn that I do not?

[mylifeandtimes]

the way they smelled and the way the world smelled when the knowledge was shared.

smell, of course, being one of the oldest and strongest senses. And one which incorporates a vast amount of knowledge. True, most of this knowledge is non-verbalizable, but that's true for many many forms of knowledge.

I can think of a number of other things which would also be lost by video, but smell was an obvious choice.

As for practical, let's say I was teaching you to cook, or to hunt, or to practice medicine. Several areas where smell gives really rich information.