# Our offline lives are a mixture of explicit and implicit social graphs; it's not a case of one or the other, they co-exist and sometimes even overlap.
Our explicit graph is composed of our family and friends while implicit graphs are everywhere and we pass through them constantly throughout our day.
The iPhone and Android application Color has really kick started the discussion around this subject. While it may not have launched to the best reviews it points to an interesting future: removing our reliance on online social graphs in favour of more organic connections based on our circumstances
The biggest issue Color, and any other similar network faces, is getting the number of people using it to a tipping point where it becomes worthwhile.
Without realising it
In life we become part of implicit social circles without even realising that is what they are. Football fans on the terraces have been doing implicit social graph for years, coming together in one place for a specific purpose and interacting for the duration of that event. The graph then dissolves after the final whistle when everyone goes their own separate ways.
On the commute to work regular travellers sitting in the same seats every day talk to each other forming an implicit graph for the duration of the journey. Even while at work people thrown together based on their jobs - a slightly more permanent and repeated implicit graph but one nonetheless.
Could existing social networks such as Twitter and Facebook add an implicit mode? Believe it or not, our usage of these services already operates implicitly right alongside our more traditional, explicit use.
Sport, elections, natural disasters - any time we search on twitter for a specific hashtag we are entering in to an implicit social graph. We use Twitter in different ways for different purposes. Those same football fans may come together online rather than at the game.
I have a saved Twitter search for the hashtag #saintsfc which I use to watch for updates and talk to other fans when Southampton Football Club are playing. The fans join together for a short period due to a shared interest and return to their usual timelines after the match but this type of graph is recreated in a similar form at the next game.
Repeated interactions within implicit graphs can lead to a bleed from the implicit to explicit - once you get to know some of those from the implicit graph they become 'friends' and, after a while, can be invited over in to the explicit graph.
The talk of implicit social graphs ties in with the ongoing discussion over online identity; just as in real life we don't deal with everyone the same way based on the circumstances. While an explicit graph is structured and familiar and we may feel comfortable with specific boundaries it does not accurately reflect our lives.
There has been discussion as to whether services like Color could steal some of the thunder from the main social players but does this have to be the case? Could existing social networks build implicit graphs into their current frameworks?
Facebook already has elements of the implicit graph; take checking in with Places, for example: as well as registering your own status you are advised who else is "here now". As I have already mentioned, hashtags are the basis for implicit graphs.
Could the networks build on this and created threaded conversations?
Instead of just checking in to a location or event could you not check in to a timeline for that event? Instead of searching for a hashtag why not subscribe to a separate timeline for that topic outside of the normal public timeline. Just as with Twitter @ replies that don't show to all your followers those tweets/status updates from the implicit graphs could be hidden from the public timeline - self-contained mini networks.
Twitter and Facebook already have the one thing that Color does not: a large number of users, by utilising these implicit social graphs could become a success.
The social web is still evolving and we may have just seen where it will grow next.
Image by Mark Botham