Recommended: Mugging

When you search for an item, Amazon makes suggestions of other things, such as in their “Frequently bought together” links. Here, Amazon in the UK has served up items frequently sold with that particular baseball bat.

We humans immediately get the (unintentional) joke. This Amazon page is also a great example of how a theory can explain what correlation alone cannot. People had bought these items together frequently enough—“frequently enough” is undefined—that the algorithm served up more things a mugger might want to obtain. The search algorithm uses correlation to make suggestions; humans instinctively and immediately understand the larger context, based on our own “model” or “theory” of the world around us.

The strength of Amazon’s algorithms is in linking things that seem unrelated, because other people have bought them at the same time in the past. On the other hand, the strength of humans is our ability to create a model of the world around us, test that model, and make corrections.