Testing Classification Rules
Having a dataset consisting in couples x and y, where x is each element of the population and y the class it belongs to, a classification rule can be considered as a function that assigns its class to each element. A binary classification is such that the label y can take only a two values.
A classification rule or classifier is a function h that can be evaluated for any possible value of x, specifically, given the data, h(x) will yields a similar classification as close as possible to the true group label y.
The true labels yi can be known but will not necessarily match their approximations . In a binary classification, the elements that are not correctly classified are named false positives and false negatives.
Some classification rules are static functions. Others can be computer programs. A computer classifier can be able to learn or can implement static classification rules. For a training data-set, the true labels yj are unknown, but it is a prime target for the classification procedure that the approximation : as well as possible, where the quality of this approximation needs to be judged on the basis of the statistical or probabilistic properties of the overall population from which future observations will be drawn.
Given a classification rule, a classification test is the result of applying the rule to a finite sample of the initial data set.
Read more about this topic: Classification Rule
Famous quotes containing the words testing and/or rules:
“Traditional scientific method has always been at the very best 20-20 hindsight. Its good for seeing where youve been. Its good for testing the truth of what you think you know, but it cant tell you where you ought to go.”
—Robert M. Pirsig (b. 1928)
“The average educated man in America has about as much knowledge of what a political idea is as he has of the principles of counterpoint. Each is a thing used in politics or music which those fellows who practise politics or music manipulate somehow. Show him one and he will deny that it is politics at all. It must be corrupt or he will not recognize it. He has only seen dried figs. He has only thought dried thoughts. A live thought or a real idea is against the rules of his mind.”
—John Jay Chapman (18621933)