David Smith, a (local!) iOS developer I really admire, recently started doing a series called As I Learn WatchKit documenting his experiences developing for the Apple Watch. He's also been experimenting with video posts, which got me thinking about video as a medium for conveying information in general. (Most of my thoughts about video could be applied to audio as well.)
I'm really of two minds about this. On one hand, video can be great for demonstrating things visually that are hard to describe in words. (The old adage "A picture is worth a thousand words" exists for a reason.) Video can also help to present complex topics, because information is conveyed relatively slowly in a structured narrative. (I'm imagining a great lecture by a talented professor, for example.)
On the other, text has a lot of advantages over video. It's searchable, and if you're looking for a specific piece of information, it's easy to skip right to it. Most people also read more quickly than the spoken word, meaning it's possible absorb more information quickly in written form. You can also skim the text to see if it's what you're looking for before spending the time to absorb the whole thing.
I often finding myself referring to ASCIIwwdc when I need to refer to Apple's WWDC sessions. The sessions are fantastic, and in general I highly recommend watching the videos, but there are times when I just need to grab a quick snippet of information. Without searchable text, I'd be stuck scanning through sessions looking for what I need. Moreover, I'll often use the text as the starting point to see if a particular session covers what I think it covers, so I don't accidentally spend an hour watching the wrong one.
Similarly, I sometimes find myself clicking on a link on the Washington Post web site, only to discover it's a piece of video content. When that happens, I'll usually close the tab. With text, I often want to scan the start of the article before I'm sure I want to read the whole thing in detail. With video, there's no good way to do that, and so I bail out unless it's a topic I'm extremely interested in.
On the whole, I think I enjoy audio and video most for two kinds of content: narrative (e.g. movies or documentaries) and discussion (e.g. a podcast). In both cases, the experience of watching or listening to the content is usually as much the point as the content itself. For example, a big part of why I enjoy listening to ATP is the back-and-forth between Marco, John, and Casey. It wouldn't be as much fun in written form, and I think would lose a lot of the nuance conveyed by hearing their actual voices. But even in that case, I've occasionally found myself wishing for a transcript of ATP shows to refer back to a particular point.
Of course, a transcript isn't practical in most cases - they're time-consuming and/or expensive to generate. A companion article would usually be needlessly duplicative. So, what to do in cases where you want to use video? I suggest providing a short outline of the video's contents. Key terms helps with search, and an outline lets users do a quick scan of the content before committing to watching the whole thing. Even better, the outline could contain rough time indices, so it's possible to skip to a particular section of the video. In many ways, the outline would function similarly to the show notes published by some podcasts. Hopefully, that would give viewers the best of both worlds without generating too much overhead for the video producer.