One of the notable side effects of not building cities the way Jane Jacobs suggested is that many North American cities are designed not for people on foot but for people in cars. Instead of local neighborhoods which, of necessity, provide for all the basic needs of a population and are thus innately diverse, people drive to places that interest them, to meet people that interest them, and bypass the people and things that don't interest them. People in the sprawling burbs and zoned areas of great American cities often don't know their own neighbours but gather in self reinforcing cliques where, in a city of sufficient size, it is possible to find people that share all sorts of interests, including the sinister and unsavory as well as the positive and affirmatory. Intricate social networks of place are replaced by sets of people and things that relate to our needs and interests: networks within those do emerge, but they are networks of affinity. Ghettos in cities hardly matter any more as we can ghettoise our own lives by skipping the limitations of location through the use of vehicular transport. It's an exaggeration, sure, but it's a tendency that becomes ever greater, ever more self-reinforcing because of thoughtless planning.

On the Internet have mostly built our networked spaces like those great American cities, but we have added some new flavours to the mix. Confirmation biases arise when we engage in social networks with (mostly) only those we already know (our nets) or those who share an interest (our sets) or those engaged in collaborative activities (our groups). We create sites for our courses, sites for work, sites for hobbies, and so on. On our desktops or other forms of collecting information and feeds, our news sources can and do become more personalised, tailored to our interests and focusing our attention on what we already focus our attention on and, because the Internet is vast, there is always something to meet ever-more more refined and specific interests, usually a Google search away. Much of the time we see what we want to see, engage with whom we want to engage about things we want to engage about. If someone is boring us, we will not cause offence by ceasing to pay attention because, mostly, they will not know we have stopped listening.

I once built a little play space called Dwellings that was an attempt to reintroduce the succession of eyes found in the diverse and thriving neighbourhoods of which Jane Jacobs wrote so eloquently and that can still be found in many parts of the world, and even parts of a fair number of North American cities. A cross between a collaborative browser, a MUD and a shared bookmarking system, it attempted to apply the dynamics of thriving city district to a web site. I was pleased with the concept even though the actual environment worked terribly the moment more than a handful of people came by. However, more than that, I have come to realise that it could not ever work as I had hoped. On the Web, you are a gesture or mouseclick away from anywhere. Constraints of a site are only an issue if you have to engage with it but, on a site that you do not have to navigate your way around, the obvious way to bypass constraints is to go somewhere less constraining. But, if it is a site with which you have to engage then it is just another of those isolated spaces that we go to for some reason, seldom a space that we pass through because we are on our way somewhere, so it is unlikely to result in the rich diversity necessary to break out of a set-oriented or net-oriented self-reinforcing view of the world.

I'm not sure that there are any neat solutions that employ common technologies. Finding ways to reintroduce ourselves to our communities of place would help. Similarly, if we build more virtual spaces that have more diversity, then there is a greater chance of serendipity and movement between social forms and milieus, but it is hard to imagine that will become sufficiently ubiquitous as a design ethic to stop the tide as the whole point of specialised spaces is that people know what to expect and that's why they are there. I quite like what happens in some popular aggregators like Pulse, that do make it easy for one to filter and shape things to one's liking, but that also provide pre-built feeds that are more like a traditional newspaper, with consequent opportunities for border-crossing. However, if there is too much variation, then we will probably stop using them: given the choice between something that shows us things we like because they are like us and things that we may occasionally like but mostly don't, most of us will follow the things we like.

Or perhaps, as one of the literacies of this networked age, we should nurture and cultivate the skill of deliberately opening ourselves to serendipity. For instance, maybe we should all follow one link every day that has no apparent interest to us, or subscribe to a random feed (some sites like Boing Boing are not far from that already). In the long run, to paraphrase Mcluhan's paraphrasing of Churchill, we are the shapers of the tools that shape our lives.