Today we assume that the search engine can locate all of the matching pages (precision) and return relevant results. Google, considered the de-facto engine by many technies has rocketed Google into a billion dollar industry, with over a dozens contenders (Magellan, Alta Vista, MSN, Mama, Etc) ripping at Google’s heels.
From an academic perspective, the “best” search engine is the one that returns the “right” answer, the one that derived the “meaning” of the query and returned on-point results. Old research attempted to qualify the quality of search engines using difficult metrics such as Search Engine Precision and Recall.
A central part of quantifying the “relevance” of any query is to “expand” the query into a more complex query. For example, consider the query:
cheap condo Los Angeles no credit check
Word Stemming
“Word stemming” is defined as the ability to include word variations. For example any noun-word would include variations (whose importance is directly proportional to the degree of variation) With word stemming, we use quantified methods for the rules of grammar to add word stems and rank them according to their degree of separation from the root word. For example, we might see stems identified for “cheap”, “condo” and “check”: