Besides crawling, people
can also study OSNs by monitoring the corresponding
network traffic. Benevenuto et al. [6]
analyze the user behavior of OSNs based on
detailed clickstream data obtained from a social
network aggregator, as illustrated in Fig. 1.
In [6], the clickstream data was collected over
12 days with HTTP sessions of 37,024 users who
accessed popular social networks. This article
defines and analyzes the OSN session characteristics:
• The frequency of accessing OSNs
• Total time spent on OSNs
• Session duration of OSNs
Through the clickstream data, user activities are
also identified. Forty-one types of user activities
are classified into nine groups, and the popularity
of different activities and the traffic bytes are
Figure 1. Data collection through a social network aggregator.
3. OSN activity
1. User login
2. Authentication
to all sites
Social
network
aggregator
Data collection
Data collection through social network aggregator
A fast increase in the
number of users
makes the size of
social graphs larger
and larger, which
presents researchers
with a big challenge
when performing
any analysis with limited
computation
and storage capability.
Graph sampling
techniques are used
to get a smaller but
representative snapshot
of social graphs.
IEEE Communications Magazine • September 2013 147
analyzed. Interestingly, it is found that silent or
latent interactions such as browsing account for
more than 90 percent of user activities. Also,
they show how users have different activities in
different OSNs. They also characterize how
users transit from one activity to another using a
first-order Markov chain.