Wiard,
Given the letters from Arles, how many letters have the term 'Gauguin'? Or: Given the letters from Arles, how many letters have the term 'Gauguin AND Pissarro'?
It depends on the input data. Did you manage to write a query that pre-selects the letters from Arles?
Can you see from the query, printed in blue, whether it gives the tf/idf score? While making the database I checked the td/idf score in the full text search option.
You'll have to check the query info to see if the tf/idf scoring is used. If the compilation steps include sth like "Applying full-text index", you can be sure that tf/idf is used as scoring. Otherwise, the default scoring (..which often yields better results for XML documents..) is utilized.
Hope this helps, Christian