It has surely happened to you more than once. You enter the app or go to the Facebook website and a message appears on your wall with the profile picture of several people indicating that “Maybe you know these people”. How does Facebook know the people you know? How does the friend suggestion on this popular Social Network work?
The algorithms Facebook use are complex and powerful, and although we cannot know exactly how they work, the Social Network itself has been giving us clues to understand.
On a Facebook page we are provided with a little bit of information on how the Social Network uses contacts for the section “People you may know”: «We show you people based on common friends, information about jobs and studies, the networks you are part of, the contacts you have imported and many other factors» .
The operation of these Facebook algorithms are mainly based on large-scale data crossing in search of matches between contacts. This is one of the reasons why the technology giant constantly insists us to complete our profile to the fullest: the more data they have about us, the easier it is for their algorithm to find matches or pair us up with friends and acquaintances.
For example, if we fill in the field of school, institute or University, with some studies and a certain date, the Facebook algorithm will take it into account and suggest us to people who have filled them in identically, who would be our former colleagues.
This algorithm process also applies to other situations, as in the case of co-workers, although this is not the only way to suggest friends or acquaintances since it also takes into account our family situation, and it is usual that we receive suggestions of friendship from friends and family of our partner.
Mark Zuckerberg’s company accumulates so much data about us that it could trace a complete psychological profile quite accurately. Logically, processing such a large amount of data is not simple, and requires a large investment in servers. Something for which Facebook has stood out since its inception, devoting a huge amount of investment to “Big Data”. In addition to the suggestion of friends and looking for interconnections within the Social Network itself, most of this data is used for advertising purposes, showing each of us ads that may interest depending on our tastes.
The suggestion of Facebook friends can be very useful to recover contact with people who otherwise would have been impossible to find, however, some aspects of the operation of its algorithm are not clear.
One of the usual suspicions is that Facebook uses the location of our device to suggest friends that have been in the same places, which does not always mean that we know them and it would clearly be an invasion of our privacy.
Although Facebook has always denied this practice, the controversy arises from time to time and feeds each time its algorithm suggests people we don’t know anything about. Be that as it may, in the end it is we who provide the data to Facebook voluntarily, so it is in our hands to lose some privacy in exchange for reconnecting with friends and acquaintances that we have not heard of in years.