Analysing Obama Speeches Since 2004

#artificialintelligence 

Texts have been downloaded from this site, I have not seen the content of each of the speeches, but the overwhelming majority of these texts were told by Obama during his speeches. Anything else told by somebody else is negligible compared to the overall result of this analysis. According to Wikipedia The lexical diversity of a given text is defined as the ratio of total number of words to the number of different unique word stems.