Facebook figures out that you know Holly, although you haven't seen her in 10 years, because you have four mutual friends - a good predictor of direct friendship. But sometimes Facebook gets it wrong. 'Hey, I don't know Harry!' Roger Guimera and Marta Sales-Pardo, a husband-wife research team at Northwestern University, have developed a universal method that can accurately analyse a range of complex networks - including social networks, protein-protein interactions and air transportation networks. Although the datasets they used were much smaller than Facebook's, the researchers demonstrated the great potential of their method.
from Facebook (and systems biologists) take note: Network analysis reveals true connections