Machine learning is an area of computer science that automation engineers cannot ignore. Machine learning was developed as a specialized area of artificial intelligence. However, the boundaries of this area are blurred, and it is not always possible to clearly state whether a topic falls under machine learning or under the broader area of AI. This chapter introduces some of the machine learning algorithms and their possible applications in construction. However, machine learning requires a precise definition of the learning task. Creating a machine learning model requires a precise definition of the learning task. Clustering is an unsupervised learning tasks in which the clusters are determined automatically, whereas, in classification the class labels are provided by the user in the training data set. Like classification, the machine learning model must predict the value of the output variables for the given values of input variables.