What is automatic text summarization?

In the academic literature, text summarization is often proposed as a solution to information overload, and we in the 21st century like to think that we are uniquely positioned in history in having to deal with this problem. However, even in the 1950s when automatic text summarization techniques were in their infancy, the stated goal was similar. H.P. Luhn's 1958 paper The automatic creation of literature abstracts, available in a number of places online, including at http://altaplana.com/ibm-luhn58-LiteratureAbstracts.pdf, describes a text summarization method that will save a prospective reader time and effort in finding useful information in a given article or report and that the problem of finding information is being aggravated by the ever-increasing output of technical literature.

Luhn proposed a text summarization method where the computer would read each sentence in a paper, extract the frequently occurring words, which he calls significant words...