ABSTRACT

When seeking information on a rare disease, e.g. alveolar microlithiasis, where the instances of any mention are relatively rare even in sources accessible via the Web, the searcher may well wish to retrieve anything that refers to the disease. However, individual Web search engines only cover a small part of the indexable Web. 1,2 Metasearch engines attempt to address this and other search engine limitations by submitting search queries to multiple Web search engines simultaneously. Their main attraction is their ability to aggregate results from a range of search engines, so they may help to identify matches that might otherwise not be found by using a single search engine. A selection of metasearch engines is listed below.