Graph Search is based on data created by users while interacting with other users by simply socializing, having similar interests and sharing them, tagging photos, checking in places and more but till now the information was useful in real-time mostly. Over the years we users have punched in mountains of data while simply interacting with our friends, endorsing favorite brands, checking in to places and sharing links and content related to specific subject and the like. This unimaginably voluminous amount of data can also be analyzed and intelligence extracted based on it. This is not a new concept but its mostly businesses and researches who have applied these techniques and mostly on limited things represented in numbers.
Facebook's endeavor seems to be to use similar techniques to discover relationship between users. In fact Facebook's social graph (a collection depicting the relationship between users) is the largest dataset in the world. But it is the Interest graph that seems more promising. If Social Graph depicts how people on web are related to each other, Interest Graph which emphasizes on the interests of the users. People bonding with each other because of sharing same interests are likely to be more productive than people who connect with each other because they know each other in physical world.
|Social Graph [src: wikipedia]|
Each dot represents a person
Facebook Graph Search is likely to change that, for example if you are looking for good restaurant in a city you are visiting and your friends have previously checked in a particular restaurant. T Graph Search can help you find that particular restaurant. It is not a good example I know* :P I just want to write these before being exposed to the avalanche of news and opinion that would follow and influence mine ;)
Before concluding I must say that at the moment Graph Search seems to be way smart but geared more towards consumer culture and based on social objects, as opposed to Google which crawls and indexes web page content. A very fundamental difference between the two is that while search engines return a list of link to a search query, Graph Search is meant to give answers. It also means that Facebook may have also found an online ad-based monetizing model. As I said in the beginning, Facebook wants to connect people while Google's motto is to organize world's information. May be they should stick to their strengths....
*You can find better examples here http://newsroom.fb.com/News/562/Introducing-Graph-Search-Beta
For preview visit https://www.facebook.com/about/graphsearch
Note: Graph Search isn't available yet but even when it does initially it would allow search in four categories only - People, Photo, Places, Interest