model function, nearest neighbor method, data interpolation, overfitting and underfiting, regularization noise vs. features If you know a property of the underlying distribution, noise and the important underlying feature could look very similar (think a sinusoid vs. just Gaussian noise). learning learning is the practice of training a system to do something…. knowledge based system A John McCarthy-esque learning system using knowledge: 1) knowledge base, with explicit facts with experts and 2) an inference engine, a way to reason and generate new facts. This approach is discrete and has no inherent error machine learning see machine learning