The depth of query support provided increases the likelihood of finding exactly what is of interest. For example, HotBot provides many options for filtering and parsing a query through a series of drop-down menus and buttons. AltaVista and Northern Light also offer excellent support for query structuring. Most searches are conducted based on keywords. Although a single keyword can be used, the user will usually want to include at least two, in order to increase the relevancy of the sites located.
Boolean operators can help specify the topic.
If a word is misspelled, the results will be irrelevant. String matching is incapable of recognizing meaning or context. It continues to be used, however, as it is the most efficient and inexpensive method available. Some of the search engines are using measures of website popularity in their attempt to rank site relevance. Direct Hit, Inc., introduced a technology for measuring the number of user hits on a particular site as a reflection of its relevance.