I imagine that it would be something similar to the German Tank Problem. (http://en.wikipedia.org/wiki/German_tank_problem http://en.wikipedia.org/wiki/German_

I imagine that it would be something similar to the German Tank Problem. (http://en.wikipedia.org/wiki/German_tank_problem http://en.wikipedia.org/wiki/German_tank_problem ) Taking each writing as a sample of the words that are known then would allow for an estimation of total words known. I imagine that this would need to be modified to account for the non-uniform distribution of word use, but the principle would be the same.