What is classification

Classification is the process of categorizing data into different classes or categories based on its features. In the context of machine learning, classification refers to the task of predicting the category of a given input data point, primarily using supervised learning. Methods of classification we will be discussing today:

• Decision Trees
• Naive Bayes
• KNN (k-nearest neighbour) algorithm

Definitions

Supervised Learning • Providing labeled training data with known correct answers • Example: Annotated cancer cell images for computer vision training

Features • Characteristics of data used for classification • Example: Estate location or number of rooms

Classes • Categories that data points are sorted into • Example: Messages labeled as spam or not spam

Regression techniques can be adapted for classification tasks • Example: Linear classifiers

Types of Classification Problems

1. Binary Classification: classify instances into one of two classes or categories

1. Multiclass Classification: Classify instances into >2 classes, each sample being only assigned to a singular label

1. Multi label classification: each instance can be assigned multiple labels simultaneously