Handwriting recognition, flying helicopter, checks, US Mail sorting, credit card fraud detection, classifying human genome, etc.
Field of study that gives computers the ability to learn without being explicitly programmed (Arthur Samuel, 1959 who wrote Checkers program that played 1000s of games with itself and learnt to recognize board positions that are good/bad and eventually played better than Arthur Samuel)
Recent Definition: A computer program is said to learn from experience E w.r.to some task T and some performance measure P, it its performance on T, as measured by P, improveds with experience E.
Providing the algorithm the "right answers" for a number of cases.
In classification problems, the right answers are discrete values (e.g., Is tumor malignant?)
No right answers given -- the program finds structure in the data such as clusters. Applcations include image processing to group pixels; group gene data; market segmentation; social network analysis; astronomical data analysis. An interesting application (using independent component analysis) is seperating the voices of individuals at a cocktail party using multiple microphones.
Machine learning deals with the problem of extracting features from data so as to solve many different predictive tasks: