Social graph: concepts and issues

Our society spawns one gigantic social graph. In this graph, each one of us is a node. There is an explicit connection, if we know each other. For example, two people can be connected because they work together or because they went to school together or because they are married.

Users want to own their personal information. When any social network starts, it is hungry to leverage other networks. As it grows, the incentive to share information like social graph and attention with others diminishes (unless it is done via an API that continues to benefit the network). But as individuals, we do not care about either young or old networks. We care about ease of use and privacy.

What is also remarkable is that a lot can be said about a graph by looking at its structure; and the evolution of the structure. For example, epidemiologists use graph structures to predict the spread of an epidemic. The very same model can be used to understand how wild fire spreads, as well as how to engineer a viral marketing campaign. The better we understand the structure of a system’s graph, the more we can control it, predict it and analyze it.

Famously, the social networks have a so called Small World property - more widely known as the Six Degrees of Separation. This is both an anecdotal and scientific observation that we all are connected to each other - no more than six people away.