Search methods
The search engine evaluates the results statistically (according to relevance) and lists them in the corresponding order. Words like "on" and "to" have a very low rating.
You can search for one or several words at the same time. You can also enter a whole sentence:
Federal President Köhler on his state visit to India.

OR operator when entering several keywords:
This search finds everything on state visits, though these do not necessary have to be state visits to India. In addition, EVERYTHING containing (just) 'Chancellor' or (just) 'Schröder' or even just 'India' is displayed!
If you enter several terms (separated only by a space between each word) each individual word is searched for, independently of the others (!). A logical OR operator exists between the individual words, i.e. at least one of the words is contained in the hit document, although sometimes the document contains several or all of the words at the same time:
Federal President Köhler state visit India