Google search terms, conceived as the frequencies of page counts returned by Google divided by the number of pages indexed by Google (multiplied by the average number of search terms in those pages), approximate the actual relative frequencies of those search terms as actually used in society. Based on this premise, the relations represented by the normalized Google distance approximately capture the assumed true semantic relations governing the search terms. In the NGD the World Wide Web and Google is used. Other text corpora can be Wikipedia, the King James version of the Bible or the Oxford English Dictionary together with appropriate search engines. Properties The following properties are proved in: The NGD is roughly in between 0 and . It can be slightly negative. For example, "red red" gives about 20% more hits of Google on the World Wide Web than "red." (Mid 2013 there were 4.260.000.000 hits for "red" and 5.500.000.000 hits for "red red". Presently, "red red" now returns far fewer results than "red".) If the then we view x and y as very dissimilar. The NGD is not a metric. In the beginning we have seen that the NGD is zero for x and y that are not equal provided x and y do always occur together on the same web page. From the NGD formula we see that it is symmetric. The triangle property is not satisfied by the NGD. However, these results are theoretic. It is hard to come up with practical examples of the World Wide Web using Google that violate the triangle property. Applications Applications to colors versus numbers, primes versus non-primes and so are given in, as well as a randomized massive experiment using WordNet categories. In the primes versus non-primes case and the WordNet experiment the NGD method is augmented with a Support Vector Machine classifier. The experiments consist of 25 positive examples and 25 negative ones. The WordNet experiment consisted of 100 random WordNet categories. The NGD method had a success rate of 87.25%. That is the mean is 0.8725 while the standard deviation was 0.1169. These rates are about agreement with the WordNet categories which represent the knowledge of researchers with PhD's which entered them. It is rare to see agreement less than 75%. References Related Literature R. Allen and Y. Wu, Metrics for the Scope of a Collection, JASIST, (2005), 55(10), 1243-1249 M. Li and P.M.B. Vitanyi,