Research has shown that the average user's search query is only 1.2 words long. Short Boolean queries cannot express exactly what the user is looking for, and as a result, search results returned by the engine are often irrelevant and incomplete. Automatic categorization can solve this problem, without requiring that users become trained researchers.

Problem				Solution
Users search for subjects. Users searching for documents about computers are likely to use the search term "computers." But the name of the subject may not appear in the document at all. For example, a description of IBM's new product may not contain the word "computers," because it is obvious to human beings that computers are involved.				Concept searching: With automatic categorization, documents have meta data that defines what they are about. The search engine can then find documents about "computers" even if they don't actually contain that word.
Documents containing synonyms are not returned. A 1.2 word query can't contain all the possible synonyms of the terms being searched. If the user searched for "computers," documents containing the word "PC" won't be returned at all, and the user will not know they exist.				Documents containing synonyms are in the same category. With automatic categorization, all the documents about computers will have the "computers" category as meta data. Documents containing the word "PC," or another related term, will be retrieved because they are in a relevant category.
Irrelevant search results. In the absence of meta data, search engines must rely on the occurrence of words in a document to rank its relevance. A search engine may give a low ranking to a document that is actually about the subject in question, simply because it contains too few occurrences of the search term, and bury it on the 17th results page.				Ranking by meta data: With automatic categorization, search engines can rank documents higher if they are actually about the subject, or contain related keywords: These are the documents that will have real value for users. Other documents, which contain the search term but do not belong to the relevant category, will be ranked lower.
Users never get the "big picture." Search results are always missing something, because most search queries aren't perfect. Users never know for sure that they are seeing all the documents about the subject at hand.				Comprehensive search results: With automatic categorization, documents are consistently classified into categories. A user searching for a certain category's concept will get all the documents belonging to that category.