What is the social graph

During my recent work on creating a searching tool that uses the information from the social graph to rank the search results I came across a major problem... the social graph as you define in your social network service is accurate today but inaccurate tomorrow... and you have some people there that you barely know and some other that aren't there but happened to be the closest people to you... would ranking based on what I put in facebook myspace linked or others is the right way to rank results... how do I keep it accurate updated and what is the right or most relevant way for me to approach people I want to get introduced.

Definitely there is a need for technology with better algorithms that can learn and anticipate the right results, the group of algorithms that can cover that end are behavioral algorithms that have a learning machine with success parameter in them. these set of algorithms are used to measure human behavioral interaction with the search results anticipate the personal parameters and create a way to rank the strength of relationship between two people in a social graph where the direction does matter.