The nearest neighbor
Win an EXCITING GIFT upon the correct completion of exercise.
The idea is to use the very simple principle that users with similar past behavior tend to have similar future behavior. Imagine a music recommendation system that collects data about users’ listening behavior. Let’s say you have listened to 1980s disco music (just for the sake of argument). One day, the service provider gets their hands on a hard-to-find 1980 disco classic, and adds it into the music library. The system now needs to predict whether you will like it or not. One way of doing this is to use information about the genre, the artist, and other metadata, entered by the good people of the service provider. However, this information is relatively scarce and coarse and it will only be able to give rough predictions.
In this exercise, we will build a simple recommendation system for an online shopping application where the users’ purchase history is recorded and used to predict which products the user is likely to buy next.
We have data from six users. For each user, we have recorded their recent shopping history of four items and the item they bought after buying these four items: