"Ways to find a needle in haystack"
Information overload is almost a passé term; however, it is still valid. Information retrieval is a big arena and most of it is far from being solved. However, that being said, we have come a long way and the results produced by some of the state-of-the-art information retrieval algorithms are really impressive. You may not know that you are using information retrieval but whenever you search for some documents on your PC or on the internet, you are actually using the product of an information retrieval algorithm in the background. So as the metaphor goes, finding the needle (read information/insight) in a haystack (read your data archive on your PC or on the web) is the key to successful business. This chapter is dedicated to showing you how you can code up some of the popular and useful information retrieval algorithms using F# and then use them in your problem domain.