New knowledge is the most valuable commodity on earth. The more truth we have to work with, the richer we become.
—Kurt Vonneguti
Unsupervised learning is a machine learning task that finds hidden patterns and structure in the dataset without the aid of labeled responses. Unsupervised learning is ideal when you only have access to input data and training data is unavailable or hard to obtain. Common methods include clustering, topic modeling, anomaly detection, and principal component analysis.