Using bias to forge a more accurate consensus

I distinctly remember a post where I said that if you have multiple ideological perspectives that lead you to the same conclusion, you're much more likely to be right. I can't find that post, but see also this one on how a consensus is stronger with disagreement and this one about modelling how Wikipedia articles arrive at a consensus through moderated discussions.

In their new Nature Human Behaviour paper, “The Wisdom of Polarised Crowds,” Evans and Teplitskiy concluded that polarisation doesn’t poison the wells of information. On the contrary, they showed politically diverse editor teams on Wikipedia put out better entries—articles with higher accuracy or completeness—than uniformly liberal or conservative or moderate teams. It’s a surprising result and so I caught up with Evans and Teplitskiy to offer their interpretations.

It doesn't strike me as surprising... if and only if you can get opposing sides to agree. If they remain ideologically opposed but do agree on the raw information under discussion, I should think there's a very high probability that that information is correct (see also this for more on how social media can be used to fight polarisation rather than increasing it). This doesn't mean the resulting articles will necessarily be persuasive to others, however. And this discussion process is not easy :

People talk about the importance of diversity. It’s not diversity in general; it’s diversity in specific. If you have these different ideologies, it’s associated with different filters on the world, different intakes of information, and so when it comes to constructing reference knowledge on an encyclopedic web page that’s supposed to thoroughly characterise an area, you do a much better job because you have a lot more information that’s attended to by this ideologically diverse group.

Editors working on a social issues page said, “We have to admit that the position that was echoed at the end of the argument was much stronger and balanced.” Did they begrudgingly come to that? They did, and that’s the key. If they too easily updated their opinion, then they wouldn’t have been motivated to find counter-factual and counter-data arguments that fuel that conversation. We found that more diversity is associated with longer conversations. If they were immediately willing to give up on these things, then it wouldn’t have produced the sustained competition that ended up generating the balance that they, themselves, came to appreciate. 

An important and interesting caveat is that diversity does not guarantee improved accuracy. Issues which are genuinely settled do not benefit from more diverse perspectives :

There are few places where there’s enormous amounts of certainty in the sciences. My guess is in places where there is strong certainty, we’re not going to see a big effect from political diversity. Political diversity is not a magical substance. If the distribution of political perspectives aren’t correlated with useful information about the topic at hand, then you’re not going to see a benefit. You’re going to see noise. You might even see a detriment.

All that seems entirely reasonable to me. I think the following probably needs some clarification though :

What do you think about fake news?
The thing most disturbing to me is the onslaught of claims about fake information and fake news. In some sense, all information is fake. All of it has a purpose, an angle. But the fact that now it’s just so easy to claim that it’s fake without any particular support for that claim, and it’s popular to do so, means it’s easier to discount alternative information than ever before. Angles are useful. They motivate people to look in a certain place, to search out information that you probably wouldn’t have searched out if you weren’t motivated by the possession of a belief. Angles end up having a lot of value, unless you discount them all. 

I think that ducks the question. Yes, it's easy to claim something you don't like is fake (people have done that since time immemorial). But it's also true that some news is actually just a pack of lies (again, people have done that since time immemorial). The only "angle" fake news has is its attempt to confuse rather than convince. It is most definitely not useful and is completely counter-productive to the effort to obtain accuracy. Objective facts are a real thing.

My hope is that not just scientists, but people with opinions and political stakes in general, can seriously consider the fact that people who don’t share their political viewpoints have something valuable to say—and even if they don’t have something valuable to say about a particular political topic, that their different experience and perspective has likely given them access to other kinds of information that will be valuable and new to you. That’s the key to unlocking the potential of polarisation: to allow people to constructively contribute to knowledge projects and other projects together. If you know enough about Wikipedia to open up the talk page, which anybody can do but almost nobody does, you’ll see extensive discussions going on. You’ll see people carefully, painstakingly employing diverse perspectives that are perceived by experts as being systematically better. It just produces more robust knowledge because there’s less ideological filtering going on.

This I like. I would add, though, that moderation of the is a key element of Wikipedia discussions in establishing accuracy and maintaining a civility to the articles not usually found in other arenas of debate. Implementing such policies elsewhere would be far from trivial... if you can get diverse people to agree, then yes you've probably got a more secure finding, but actually getting them to agree is bloody difficult - and it's even harder if you want to avoid making them even more polarised in the process.

Wikipedia and the Wisdom of Polarized Crowds - Issue 70: Variables - Nautilus

In 2013, James Evans, a University of Chicago sociologist and computational scientist, launched a study to see if science forged a bridge across the political divide. Did conservatives and liberals at least agree on biology and physics and economics? Short answer: No. "We found more polarization than we expected," Evans told me recently.