202511200951 Status: idea Tags: Datascience, Recommender systems

Content-Based Filtering

  • Content-based methods describe users and items by their known metadata. Each item i is represented by a set of relevant tags—e.g. movies of the IMDb platform can be tagged asā€œactionā€, ā€œcomedyā€, etc. Each user u is represented by a user profile, which can created from known user information—e.g. sex and age—or from the user’s past activity.
  • To train a Machine Learning model with this approach we can use a k-NN model. For instance, if we know that user u bought an item i, we can recommend to u the available items with features most similar to it.

The advantage of this approach is that items metadata are known in advance, so we can also apply it to Cold-Start scenarios where a new item or user is added to the platform and we don’t have user-item interactions to train our model. The disadvantages are that we don’t use the full set of known user-item interactions (each user is treated independently), and that we need to know metadata information for each item and user.


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