Approach
What are Social Networks ?
Social networks are "actors" linked by "relations". Actors are generally humans and relations are various such as kinship, friendships, email communication or phone calls. Social networks can be trees or graphs. We generally use indistinctively graph and network.
Social networks are interesting because most of them present a specific structure. This is called the small-world phenomemon: each actor is linked to any other in the network with a maximum of 6 intermediaries!
Node-link diagrams and matrices
Node-link diagrams are a very intuitive way or representing a social network and a graph in general: nodes are actors, links are relations. However, there are readability issues when the network is becoming larger (node overlapps and link crossings).
In matrices, actors are rows and columns (represented twice), relations are a block at their intersection. Matrix-based representation are far less intuitive but they are a good solution when the network is large or dense. One of the major issues with matrices is to reorder their rows and columns to let interesting patterns emerge.
Participatory design
To understand the needs of social science researchers, we use participatory design techniques such as interviews, brainstorming and video brainstorming. We focused on a couple of specific questions for large social networks visualization and navigation: how would you like to explore your network? how would you like to create and edit your network? We ended up with a set of requirements and aspirations for a visual and interactive system oriented towards exploration.
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