I am curious about corpus linguistics, and especially in this case how corpora is used to prove the Brevity Law, also known as Zip'f law of abbreviation. Simply put, this theorem postulates that the shorter the words are, the more often they occur in language. Of course, visualization will make a great sense of proving the theorem, so I went across this visualization from Wikipedia:
The x-axis stands for word character length and the y-axis stands for word count, in log per-million count.
My question is, why using log per-million count? Is it for normalization so that the words with lesser counts are well represented in the analysis? Anyone giving an insight to this, as well as some little readings, would greatly appreciated.
Thanks in advance!