They can search by keyword, which automatically retrieves exact matches. This is the simplest form of indexing and retrieving files. However, keywords searches require someone to define the relevant terms and assign them to the file. Incorrect keywords or the occasional keyword with dual meanings can reduce the accuracy of these kinds of searches. The Boolean system, which was designed to overcome the shortcomings of keyword searches, relies on indexes that identify every word in a document.
Users have the advantage of running queries on a large group of documents using the Boolean system.
However, users often find Boolean searches can either retrieve too many or too few documents. Another search technique involves statistical systems, which rely on algorithms to determine a document's relevance according to the frequency with which a keyword appears in the document. When used in combination with statistics, concept searches can be extremely useful. Despite advancements in the technology, OCR is still finicky and can misspell words. Fuzzy searching is based on adaptive pattern technology, a form of intelligent software that allows users to index and retrieve documents based on repeating patterns in data.