Web Search Engines Search engines designed for kids contain age- appropriate content and use filtering programs that eliminate much inappropriate content. Issues Related to Search Engines Most search engines limit the number of pages that will be added to search engine databases. So not every page of a Website may be searchable. Most search engines only add the first 100 K of text of each Web page to their database, then stop. Therefore text at the end of long Web pages may not be retrievable. Search engines limit the size of their database by deleting older pages when newer ones are located. Web search engines are completely different than Web indexes. They are very much like a keyword Some search engines limit their searches to certain search of your OPAC. Search engines retrieve domains or Website portions that are considered to information for you, by running software programs be reliable and unique. called „ bots‟. There are two types of search engine bots; those that create and add to the search Bots rely on links they‟ve discovered on Web pages engine‟s database, and those that retrieve to add to their database. If a Web page has no links information from its database and arrange it pointing to it, a search engine bot can‟t find it. according to how relevant it is to your query. There‟s a lag time between the time when a Web Every search engine‟s bots are programmed page is published and when a bot discovers and differently. Some database bots are programmed to indexes it. The other lag time is when a Web page take every significant word from a Website (less is included in a search engine database and when those words that are non-searchable “stop words”), it is re-visited and updated. while other bots only add selected words or travel only so deep down a Website‟s hierarchy before Some search engines pre-program results for very stopping and going elsewhere. popular queries. Some search engines program the most popular/commonly selected Web pages to Web search engine results are arranged by appear near the top of the results list. „relevance‟ rather organized by topic. Because search engines are robot-built, they lack most of Many search engines are biased toward text and the “bells and whistles” of Web indexes. Sites aren‟t away from images and other media. If a Web page selected, nor are they evaluated and there is no only contains an image map graphic there is thesaurus to help bring similar terms together. nothing for the search engine to index. There is only one way to search - by keyword(s). Even though search engines report that they There are many different Web search engines. retrieve thousands/millions of pages, only a few Some are case-insensitive, others are case- results (between 200 and 1,000) can actually be sensitive. Each has unique features that work best viewed. Results beyond that number limit can‟t be for different searches and for varying information displayed, unless you use other/additional search needs. Search engines often retrieve way too much terms. information for the average library user.