Chapter 4. Network Analysis

Humans are very social creatures, and our ability to find connections – with each other and with other things in our lives – is one of our strongest impulses. We naturally love to connect with others, we distinguish our connections with different names or levels (friend, spouse, acquaintance, lover, enemy, BFF, frenemy, boss, employee, stranger, co-worker, neighbor), and we sometimes keep these connections for years or decades. We are fascinated by seeing people from our network appearing in other, seemingly unconnected networks. We love the notion that there might be only six (or four, or three) degrees of separation between any two people on Earth. The small world phenomenon reminds us that we are more closely connected to each other than it may appear.

So far in this book, we have experimented a lot with finding connections between things, first by finding items that are commonly associated, and then by finding entities that appear different...