Algorithm to Date Medieval Charters?

There are a lot of medieval documents in England which don't have precise dates, including many charters. According to this article from the MIT Technology Review, experts at the University of Toronto have created a computer programme to analyse the language and word use in these documents and provide close dates. If this works - it's a big if, but it appears to in the article - it would be very useful. It will be interesting to see how medievalists approach it.