I am having trouble figuring out the formula for Brunet's index which can be found in this paper http://csbapp.uncw.edu/data/mscsis/annalspaper.aspx?v=6&i=1&p=11.
I tried to apply it to interviews with ~1000 words, however, the values generated seems to be very extreme around e-100. Is this statistic not valid for large text?