Last year I coded a Facebook application for a research project. The main purpose was to discover privacy attitudes of users, and the app had to capture all user interactions. This included new friendships, deleted friendships, comment/like actions and many others.

As of today, 72 users have given permission to the app. Many of them used the application for a short time just to help me finish experiments. I, however, continue to use the application. As a result, the application has quite a formidable list of what has been going on on my profile. That list is a gold mine really.

One of the things that interest me the most on Facebook is the rationale behind new friendships. There are dozen algorithms to predict who will friend each other, but none of them answers the question “why”. I believe these works that we use today cannot really capture dynamics of a social network. A bit of sociology is needed to better understand why users become friends. As computer scientists greatly suffer from mild symptoms of Asperger syndrome, sociology is the last thing we care. That is very unfortunate, because we have the tools to analyze what is going on in planetary scale,   and sociologists have theories that can give meaning to our findings.  We have to meet somewhere in the middle. There are some attempts to correct this, and I am most hopeful about the ICWSM conference.

Back to what I wanted to write about. From my Facebook data, I wanted to see how many new friends i make in time, and if there is a correlation between months and number of friendships. We go out more in summer, and potentially meet more people. Does that mean we will have more new friendships in the summer? The answer seems to be a resounding NO. Below you will see my new friendships in summer, during a one year period.

I started with 322 friend in February, and added new friends. Dots show the days that the app finds new friends on my profile. Lines show days that no new friends were found. As you can see, there is a long period in August where I had no new friends. This is the time I was travelling in Italy, Russia and USA for conferences. As soon as I return home, you see that I make many new friends, mostly guys that I met in conferences.

Unfortunately, you do not keep all your friends in real life. Some people remove you, you remove them or many times they delete their accounts.  Social network studies do not also give a reason for why people delete each other. Some works (and common sense)  showed that posting too many messages on Twitter got people unfollow you, but we do not know what is happening on Facebook.

I have some friends that delete their accounts daily. Some of them delete their accounts whenever they go on holiday. Some only activate their accounts once in 2-3 months to check what has been going on. Then they delete it again.  Danah Boyd  investigated this deletion behavior among teens, but it was not a large study. Note that I did not know those deletions were going on until i wrote the app. Actually, first i even thought the app was malfunctioning.

Putting these temporary account deletions aside, the graph below shows how many people were removed from my Facebook friendslist in time.


If I have some free time these weeks, i will track down these deletions and check what could be the reason for them. As for the new friendships, i already have a plan to work on them. If you want to read more about this, check this out from George Danezis:

Meanwhile you can check my account and see what I publicly share.