There are many people out there that can feel the adrenaline slowly upping its quantities in their bodies, and the stress starting as we near the jolly time of Christmas. We are not all bound to spend fortunes on presents to celebrate the birth of Christ but, if you are and unsure what you should give your loved ones, then you have an excellent opportunity to try out implementing a recommender system.

If you have a friend whom you know likes books, or just looking for a book yourself, a way to approach it is by downloading one of the public datasets around with book ratings. For example, there is one collected with the book-crossings website. Using that and implementing a content-based recommender you could find similar books to the ones that your friend likes. The cool thing about content-based recommenders is that they don’t need ratings from users, so if you have descriptions of other books you can compare them with the descriptions of the books your friend liked.

So, finding the perfect present for a book-loving friend could only be few steps away:

• Get a list of what the friend likes (probably that can be found on goodreads.com)
• A data set with book descriptions
• (optional) My book to understand how to implement a content-based recommender (book)

You could also go more general and take Amazon’s product dataset, or use one with movies in which case I also describe other types of recommenders you can use, collaborative filtering, or learning to rank. I had much fun with the last one.

If you do implement a recommender, please write a comment and happy seasonal festivity, if you celebrate this one.