Designing for the Internet of Streams

According to this article from Matt Theakston at DesignWeek, the fundamental way we interact with the web is shifting from navigation between pages to flowing down a stream.  Metaphors aside, you know what I mean.  The infinite scroll in your Facebook feed is a good example.  You start at the present and you can keep scrolling down, going back in time forever with new items being added continuously as you go.  Sort of seamlessly. 

It is the “sort of” that is the point I want to talk about today.  There are many design decisions that go into how this flow works that most companies seem to be ignoring.   Facebook allows me to order the flow according to relevance or recency.  Why only those two?  And why is it a linear flow to begin with?  And why does it have to be infinite? 

An added “feature” that Facebook added recently is that if someone comments on an item, it gets re-tagged on the time dimension according to the time of the comment rather than the original post.  So something you have seen before is all of a sudden back up at the top.  This makes it harder to know what you have seen and what you haven’t seen (which is the objective I have for scrolling through my feed). 

A feature I would rather see added is a breakpoint.  For me the breakpoint would be the last thing I have already seen.  So as I scroll down this infinite feed, it would stop when I hit the point where I have already been.  If I want to go back further, that option would be available, but at least it would make it easier to find that point.  And if I want to start at the place I left off and scroll forward in time, that would become possible. 

What about other ways of ordering the stream?  Why only time and relevance (especially because the way companies like Facebook measure relevance is seriously flawed). 

And can we envision ways of making it non-linear?  Right now, we scroll down with items being added as we go.  Can we find ways to branch this infinite feed?  Perhaps I can follow all items related to an interesting business topic (even if they are not replies or cross posts).  I had a whole bunch of friends posting about New Year’s resolutions last week.  What if I could follow all of those for a time, whether they are friends, articles about how to stick to them, or funny Onion satires? 

Or what about branching in the middle of a discussion?  If someone posts a comment that sidetracks to an alternative thread, can I have an infinite scroll for both?  Our screens are rectangular, but I can imagine a window that splits into two paths.  Is there a way to make this effective?  I haven’t tried the design exercise, but I can imagine a few options.

Bottom line, if Matt is correct that we are shifting from the page metaphor to the flow metaphor, we need some new ideas for UI design.