Anomaly detection

If you've ever gotten a text saying that your bank has noticed some suspicious activity, chances are they have put anomaly detection to use. Anomaly detection is the attempt to determine whether an event, item, or object doesn't fit in with the others. One of these things is not like the other is a good way to think about it. Another name you might see for this is outlier detection.

You will find unsupervised, supervised, and semi-supervised approaches can all work in these scenarios. A depiction of what this looks like can be found in Figure 1.4 of Chapter 1, Understanding the AI/ML Landscape.

Many of the examples in this space handle more serious issues around security and safety. You'll find some examples in the following list:

• Credit card fraud
• If someone is trying to hack your account via random logins
• Unsafe operations at a power plant
• Customer buying patterns
• Illegal trading activity on a stock

There are...