Supervised Learning
Supervised learning is a cornerstone methodology in machine learning in which an algorithm learns a mapping between inputs and outputs from a set of labeled examples. Each example in the training dataset consists of an input data point (often represented as a vector in a high-dimensional space) and its corresponding output label or value, which is known a priori.
The goal of supervised learning is to construct a predictive model that can make accurate predictions for new, unseen data based on the patterns it has learned from the training data. The learning process involves adjusting the parameters of the model to minimize the difference between the predicted and actual outputs on the training data, typically using optimization techniques like gradient descent.
Supervised learning is widely applied in classification tasks, where the outputs are discrete labels, and in regression tasks, where the outputs are continuous values.
A classic example of supervised learning is email spam detection, where the algorithm is trained on a dataset of emails that are labeled as "spam" or "non-spam." The model learns to identify the characteristics of emails that are likely to be spam and can then classify new emails accordingly.
Another example is predicting house prices based on features such as location, size, and the number of bedrooms. Here, the model is trained on historical data with known prices (the labels) and learns to predict the price of a new house given its features.
These examples illustrate how supervised learning enables machines to learn from past data to make predictions about new data, automating decision-making processes in various domains, from finance and healthcare to marketing and beyond.