If you’re a nerdy professor trying to avoid grading, like I am, you might want to play around with Google Lab’s new Ngram feature.  The feature allows you to see how often a particular word or phrase has appeared within a large number of books over time.  For examples, here is a chart comparing the use of the term “failed states” to “rogue states” from 1960 to 2010 in English language books scanned by Google Books:

Or, here is a comparison of the term “Human Security” with “Humanitarian Intervention” from 1900 to 2010 in the English language holdings:

Overall the specific terms are a minuscule portion of the total words found in the collection, but it can still be interesting to see trends…

Enjoy wasting time…