Facebook's newsfeed stopped being a straightforward list of posts quite some time ago, although it's clear that a lot of Facebook users don't know this. In fact, one of the big surprises of the row about the Facebook emotion experiment was that the researchers were surprised that people didn't realise this.
Jeff Hancock, a professor at Cornell and co-author of the study, explained this in a discussion at Microsoft's recent Faculty Summit after he got a couple of hundred emails about it: "The huge number of emails about people’s frustration that researchers would change the news feed indicates that there’s just no sense that the news feed was anything other than an objective window into their social world".
Instead, he pointed out, "their news feeds are altered all the time by Facebook", and wondered (perhaps belatedly) if there should be some education about that.
Now Twitter is moving in that direction too. The Twitter timeline you see may soon include not just promoted tweets from advertisers but tweets the Twitter algorithms think are "popular or relevant" to you. They might be tweets people you do follow have favourited, or just very popular tweets.
It doesn't matter if you don't have the slightest interest in football or Scottish politics or TV music competitions. As I write this "£16m for Balotelli" is trending on Twitter, so you could expect that to show up along with tweets about the Yes campaign for the referendum and the latest wannabe pop stars and their incoherently enthusiastic fans.
So will those algorithms make for a better timeline the way Twitter hopes? Anyone who has seen the same annoying meme stuck at the top of their newsfeed on Facebook because it's doing the rounds might not agree. But when Bing and Google give you customised search results filtered by what links you've followed in previous search results, it usually means that when you search for something that has multiple meanings you're more likely to get the one you were after. You might even see different results if you run the search again because the search engine assumes you didn't find what you were looking for. (Good luck getting content farms like eHow out of your results if you make the mistake of following a couple of links that go there.) What about Amazon recommendations? They can be spot on or comically wrong.
There's an open question about where algorithmic curation is the right thing to do. I've seen complaints that Twitter already puts things in the timeline that can be upsetting (a prompt to follow an account because a now-dead relative did). Believing there is a simple algorithm for human interactions is the kind of geek fallacy that has led to Google having so many problems building a successful social network.
I wouldn't mind if Yelp reviews and rankings for restaurants or TripAdvisor hotel reviews were filtered so the score I see is based on what people who are more like me have said (rather than people who seem to expect The Ritz at Motel 6 prices). I rely a lot on those services when travelling but I always read the reviews to decide if I'm going to agree with their score. I don't think I've ever found a good app by looking at the list of apps Bing's algorithm thinks I'll want in the Windows or Windows Phone Store though.
And neither of those are about me staying in touch or having conversations with the people I've chosen to connect to. I don't believe I want to have those filtered, curated or extended by the service I'm using; using Windows Phone's remaining social integration, I see a different set of updates from what I see on the Facebook site. If that bypasses the news feed algorithms, I think I prefer it. Is there too much content from my friends for me to keep up with? I think I'd like to be the one that decides that.
Maybe if the Facebook algorithm was better at knowing what I want, I'd be more enthusiastic. After all, I'm looking forward to Microsoft's Delve that promises to do a similar thing for Office documents and co-workers.
I also wonder if pushing more 'popular' content into our feeds will mean that Twitter's non-algorithmic "egalitarian information sharing model" — which helped bring the events in Ferguson to wider attention — will make it easier or harder for people who aren't acknowledged authorities to make their point.
This raises a fundamental question about Facebook and Twitter — what do people think they are? Hancock points out: "We don’t have metaphors in place for what the news feed is. We have a metaphor for the postal service: messages are delivered without tampering from one person to the next. We have a metaphor from the newsroom: editors choose things that we think will be of interest. But there’s no stable metaphor that people hold for what the news feed is."
As Facebook and Twitter become increasingly important methods of communication for people, the fact that they arbitrarily change that communication also becomes more important. They may do it with the best of intentions, but when many users never realise the change is happening, it's time to think about what we want these services to be.
Not thinking about that is how we've let the startups and services dictate the state of online privacy. Do we want our social networks to be augmenting and altering the shape of our conversations? Do I want Twitter to make those conversations more interesting or just make them happen?