Passage 3
Searching by keyword is the most common method of using a search engine, but the problem with keywords is the relatively imprecise results and the return of a lot of irrelevant information. Keywords may have more than one meaning and search results may be found only by using a synonym of the keyword The method of browsing on the other hand takes too much to find the relevant information. Directories like Yahoo try to circumvent the problem, but the manual process of classifying material on the web takes up too much time, resulting in very few search results as not everything on the web can be classified. Therefore new paradigms of searching are needed as well as new software that is able to categorize web sites automatically.
The majority of search engines come from the United States and has specialized in English resources and information reflecting the American culture. People who do not speak English or who are non-native speakers have therefore many disadvantages on the web.
The centralized approach to information retrieval has extreme difficulty in coping with the multilingual and multi-cultural nature of the information society. The Internet has become a success throughout the world, but the American search engines operate with US centric company structure and tend to concentrate upon the English language. Although many search engines have subsidiaries in many other countries, like Japan or Italy, the way the information is presented is the American way and may not reflect the logic of the people who are using it.
National search engines in Russia or France, for example, have to deal with far smaller sets of information and specialize in the cultural and linguistic environments that they know best. Their disadvantage is that the queries are in Russian or French and the search results contain only a small subset of possible results on the web, as they are restricted to the language. This strongly reduces the possibility of using the Web as a source for the worldwide diffusion of information.
Larger search engines, such as Altavista are able to perform multilingual searches, which presents search results in multiple. This is good, if the searcher knows all the languages, but if, for example, an Indian finds a Japanese web site on the search topic, this may not be helpful.
Text documents that are in special formats (such as Postscript or Star Office Documents)are unreachable for many search engines, as the textual information is embedded into the binary structure of the particular file format. The same applies to scanned documents, Java applets and video/audio clips. The content of these file formats is hidden from search engines today. Only if the description of the file format is known and included into the search engine is it possible to add the content for certain document types. This is relatively easy, just a matter of work. Infoseek for example, is able to index the content of Word documents. More difficult is the inclusion of content that is hidden in applications, as there is no way to tell where the information may be hidden.
The research and development in information and data retrieval is aimed at improving the effectiveness and efficiency of retrieval Individual and parallel development for database management systems has left this sector without a centralized vision and coordination between the different types of search engines Search engines on the Internet are very specific and not able to cope with multiple database formats and file types. In order to make searches complete a search engine needs to search over text, documents, images, sounds and all other media formats. So the database integration will be the single most important objective for the future of intelligent search engines.
37.The problemn with searching by keywords is ______.
A.although the results are more precise the information is abundant B.although the results are not precise the information is not enough C.the results are not precise and the information is more than necessary D.none of the above正确答案C
