Data Integration and Crisis Mappingare the central hubs of the AI ecosystem Figure 47.1 , Data Integration and Crisis Mapping are the central hubs

A network diagram (or node-link diagram) encodes relationships between entities as nodes connected by link lines. The perceptual mechanism is spatial proximity , the force-directed layout clusters well-connected nodes together, making dense sub-graphs (communities) visible without explicit labelling. The viewer's eye traces paths between nodes to understand chains of relationship. Force-directed layouts use a physics simulation: links act as springs pulling nodes together, while a global repulsion force pushes all nodes apart. The resulting position is an energy minimum, not a meaningful coordinate system.

The data structure is a tripartite network: three node groups (organisations, technologies, domains) connected by directed and undirected edges of three semantic types. The message is structural , which entities are most connected, which technologies bridge the most domains, and which organisations cluster around the same capabilities. No matrix, bar chart, or hierarchy encodes this. A chord diagram could show pairwise flows but would lose the tripartite structure. A tree would impose a hierarchy that doesn't exist in the data.

Network diagrams degrade rapidly with scale. At ~60, 80 nodes and high link density, the layout becomes a "hairball" , visually dense, analytically useless. This dataset sits at 21 nodes and 49 links (average degree ~4.7), which is within the legible range. If your network grows beyond this, the correct alternatives are: an adjacency matrix (scales well, loses spatial intuition), a chord diagram (shows flow magnitudes between groups), or an arc diagram (preserves ordering, reveals clusters through arc density).

Node size by degree. Nodes with more connections are larger, making hubs immediately legible without requiring the viewer to count edges. Data Integration and Crisis Mapping visually dominate because they have the highest degree. Link color by type. Three semantic edge types (uses, enables, operates in) are color-coded and styled , directed edges carry arrowheads; "operates in" edges are dashed. Color encodes the relationship type redundantly with style, supporting color-blind users.

Paste this into Claude Code to generate a working version of this chart, plus its data file. The result will not be a perfect replica , the goal is that the reader can run the prompt, get a chart of this type, and read its source. Generate a complete, self-contained network diagram in D3 v7. Two files:

The ideas in this chapter didn't appear from nowhere. Jacob L. Moreno drew the first sociogram in 1934 , a network diagram of which children at a girls' reform school liked or disliked which other children. He coined "sociometry" and laid the foundation for modern social network analysis. Jacob L. Moreno, circa 1934. AI-generated portrait based on a public domain photograph (Wikimedia Commons).

The ideas in this chapter didn't appear from nowhere. Jacob L. Moreno drew the first sociogram in 1934 , a network diagram of which children at a girls' reform school liked or disliked which other children. He coined "sociometry" and laid the foundation for modern social network analysis. Jacob L. Moreno, circa 1934. AI-generated portrait based on a public domain photograph (Wikimedia Commons).