Types of Machine Learning
Machine Learning algorithms are generally categorized based on how they learn. Let's break down the three main types!
1. Supervised Learning
In Supervised Learning, the algorithm learns from labeled data. This means the dataset includes both the input features (X) and the correct answer/target (y).
Goal: Learn a mapping from inputs to outputs so that the model can predict the output for unseen data.
Sub-types:
- Regression: Predicting a continuous numerical value (e.g., predicting daily ice cream sales for Bigkart).
- Classification: Predicting a discrete category/class (e.g., predicting if a user will buy a Premium Ice Cream Cake).
2. Unsupervised Learning
In Unsupervised Learning, the algorithm learns from unlabeled data. The dataset only has inputs (X), with no corresponding output/target (y). The model's job is to find hidden structure or patterns within the data on its own.
Goal: Discover the underlying structure or distribution in the data.
Sub-types:
- Clustering: Grouping similar data points together (e.g., segmenting Bigkart customers based on their favorite ice cream flavors).
- Dimensionality Reduction: Reducing the number of random variables under consideration by obtaining a set of principal variables (e.g., PCA for visualization).
3. Reinforcement Learning
Reinforcement Learning (RL) is about training an agent to make a sequence of decisions in an environment to maximize a cumulative reward.
Instead of being told the explicit right answer, the agent learns by trial and error, receiving positive or negative reinforcement (rewards or penalties) based on its actions.
Examples:
- Training an AI to play Chess or Go.
- Self-driving cars navigating traffic.
- Robotics learning to walk.