Scoring is fundamental to Lucene's search capability and accuracy. Normally, you don't see scores in search results, but it's there to help sort results by relevancy. Knowing how scoring works, its boundary will help you make informed decisions in your application design.

The goal of scoring is to objectively calculate weights to rank already matched results. The contents that are more relevant to the search criteria are sorted before the less relevant ones. This is called relevancy ranking. Lucene employs a number of techniques to perform this calculation. The expandable nature of Lucene also allows you to customize scoring and expand from the default configuration. This flexibility is part of the appeal of Lucene's popularity. In this chapter, we will first look into Lucene's scoring methodology. Then, we will explore customization techniques to expand from default behavior. The intention of this chapter is to give you a primer into Lucene's scoring implementations. Hopefully...