Building a Recommendation System using Artificial Intelligence (AI)

Have you ever scrolled through a seemingly endless list of products online, unsure of what to choose? Or maybe you’ve browsed through pages of movies or music, overwhelmed by the vast selection? We’ve all been there. Thankfully, Artificial Intelligence (AI) comes to the rescue with recommendation systems!
These clever systems use AI to analyze your preferences and suggest items you might be interested in. From the movies you watch to the products you buy, recommendation systems personalize your online experience by learning your tastes and habits. But how exactly does AI power these recommendations? Let’s delve into the fascinating world of AI-powered recommendation systems and explore how they work their magic. So, let’s build a complete recommendation system using Artificial intelligence (AI) step by step with practical example.

Step 1: Understanding Recommendation Approaches

Before diving into building a recommendation system, let’s explore two fundamental approaches:

Content-Based Recommendation:

This approach suggests movies similar to what the user has liked before. For instance, if a friend enjoys comedies, recommending another comedy film would align with this approach.

Collaborative Filtering:

In contrast, collaborative filtering recommends movies based on what other users with similar tastes have enjoyed. For example, if two friends share an interest in action movies, recommending an action film that one friend liked but the other hasn’t seen yet would be a typical collaborative filtering recommendation.
Understanding these approaches is crucial as they form the foundation for building effective recommendation systems tailored to users’ preferences and behaviors.

Step 2: Collecting Movie Ratings Data

Now, let’s gather the necessary data for our recommendation system by collecting movie ratings from our friends. We’ll organize this data into a table format where:

  • Rows represent individual friends (users).
  • Columns represent different movies (items).
  • Each cell contains a rating (e.g., on a scale of 1-5 stars) given by a friend for a specific movie.

Here’s a visual representation:

Friend Movie A Movie B Movie C
Alice 5 3 1
Bob 4 5 2
Charlie 2 1 4

In this table, each row corresponds to a different friend, and each column corresponds to a different movie. The numbers in the cells represent the ratings given by each friend for the respective movies. For instance, Alice gave Movie A a rating of 5, Movie B a rating of 3, and Movie C a rating of 1.

This structured data will serve as the foundation for our recommendation system, allowing us to analyze preferences and make personalized movie suggestions based on individual tastes and interests.

Step 3: Movie Matchmaker - Finding Similarities

Now, how can we find movies a friend might like based on their ratings and what other friends liked?

Imagine a movie recommender like a matchmaker for movies!

  • We want to find movies similar to ones a friend liked based on other friends’ ratings.
  • To do this, we can calculate the “distance” between friends’ ratings. Friends with closer distances (more similar ratings) might have similar taste in movies.

A simple way to calculate distance is by taking the difference between each rating for the same movie between two friends. The lower the difference (distance), the more similar their tastes.

Step 4: Recommendation Time!

Once we know which friends have similar tastes in movies (based on distances), we can recommend movies!

  • Look at the movies highly rated (e.g., 4 or 5 stars) by a friend with a similar taste (close distance).
  • If your friend hasn’t seen these movies yet, recommend them!

Code Example (Simplified):

# Sample movie ratings (replace with your data)
ratings = {
  "Alice": [5, 3, 1],  # Ratings for Movie A, B, C
  "Bob": [4, 5, 2],
  "Charlie": [2, 1, 4]

# Calculate distance between Alice and Bob (difference in ratings for each movie)
alice_ratings = ratings["Alice"]
bob_ratings = ratings["Bob"]
distance = sum(abs(alice - bob) for alice, bob in zip(alice_ratings, bob_ratings))

# Recommend Movie C to Alice if she hasn't seen it yet (high rating from similar-tasting Bob)
if distance < 3 and ratings["Alice"][2] == 0:  # Distance threshold and movie not seen by Alice
  print("Alice, you might enjoy Movie C based on Bob's taste!")

Remember: This is a very simplified example. Real systems use complex algorithms and more data to make accurate recommendations.

AI Example #01 - Rock, Paper, Scissors Game with AI
How to Build Your Custom ChatGPT