Understanding K-Nearest Neighbors

Machine learning (ML) algorithms are often categorized as either supervised or unsupervised, and this broadly refers to whether the dataset being used is labelled or not. Supervised ML algorithms apply what has been learned in the past to new data by using labelled examples to predict future outcomes. Essentially, the correct answer is known for these types of problems and the estimated model's performance is judged based on whether or not the predicted output is correct. In contrast, unsupervised ML algorithms refer to those developed when the information used to train the model is neither classified nor labelled. These algorithms work by attempting to make sense out of data by extracting features and patterns that can be found within the sample.