Learning Data Mining with Python - Second Edition

Representing reality in models

Given what we have done so far in the book, it is easy to forget that the reason we are performing data mining is to affect real world objects, not just manipulating a matrix of values. Not all datasets are presented in terms of features. Sometimes, a dataset consists of nothing more than all of the books that have been written by a given author. Sometimes, it is the film of each of the movies released in 1979. At other times, it is a library collection of interesting historical artifacts. 

From these datasets, we may want to perform a data mining task. For the books, we may want to know the different categories that the author writes. In the films, we may wish to see how women are portrayed. In the historical ...