Hybrid systems

We've now looked at the two primary forms of recommender systems, but you should know that, in any large-scale production environment, you're likely to see recommendations that leverage both of these. This is known as a hybrid system, and the reason hybrid systems are preferred is that they help eliminate the drawbacks that can be present when using either system alone. The two systems together create a more robust solution.

Let's examine the pros and cons of each type.

Collaborative filtering

The pros of collaborative filtering are as follows:

• There's no need to hand-craft features

The cons are as follows:

• Doesn't work well without a large number of items and users
• Sparsity when...