The ratios of improvement do change, depending on the subject matter, and which of our Brilliant Searches the user selects. A ratio of improvement between 50 to 1 and 100 to 1 is not unusual. For example, you might want to take the Boolean ANDed Brilliant Search we crafted for Excite and change it to blackbird and Beatles. Nobody has the time to review 15,000 hits and decide on the good ones. Nobody has the time to figure out Boolean logic and syntax.
Nobody has the time to figure out the right additive terms.
Especially kids doing homework and term papers. Especially grown-ups with better things to do. Especially just about everybody. That's what Encyclopedia Electronica TM does. AskJeeves is, fundamentally, a natural language interpreter.