A force-directed network diagram displays 13 named nodes connected by weighted links. Each node is a colored circle with a label, and link thickness scales with the square root of the connection weight. The D3 v2 `d3.layout.force()` API positions the nodes in a simulated physical layout, with `charge` and `distance` parameters controlling repulsion and target spacing. As the simulation ticks, the SVG elements update their coordinates via the `force.on("tick")` callback. Node colors come from the `graph.json` file, which lists people and their pairwise connections.