Who's #1?; July 2012; Scientific American Magazine; by Amy N. Langville and Carl D. Meyer; 1 Page(s)

Decisions concerning the products we buy, the Web sites we click on, the movies we watch and even where we send our children to college are all affected by rankings. But did you ever wonder who or what is making all these rating decisions? Are they subjective opinions, or is something else going on under the covers?

Put yourself in Mark Zuckerberg's place when he rated and ranked the women of Harvard University for his Facemash site that evolved into Facebook. The most straightforward method would be to ask people to vote for their favorite; a coed's rating would simply be the number of votes received. But this doesn't work well, because rarely are all votes equal. For example, an uninformed vote is usually not as valuable as one from a knowledgeable person, or, in the case of Facemash, a voter's gender might matter.