Research On The Standard System Of Heterogeneous Information Retrieve Under Web Environment

With the development of Internet and the progress of the information technology, the web information resources have become more and more since the 1980s. The web information resources are various and different in structure as well as its quantity is larger and larger. But it is lack of a description standard, and there isn't a proper protocol for different information exchange. Therefore, a research on the standard system of heterogeneous information retrieval under the web environment becomes an important topic of current information retrieval area. Based on the above backgrounds and from different points of view, the paper gives a systematic research on some main protocols and criterions which are used on the web heterogeneous information retrieval now.The paper is divided into three parts:The first part(chapter 1 included) fistly analyses the characters of current web information resources and the new requirement on the web information retrieval system; followly it investigates the development of web heterogeneous information and the main topic of current study; At last, it gives a summary on the actualities and existent problems of heterogeneous information retrieval.The second part(chapter 2 to chapter 6) is the emphases and difficulties of the paper, which mainly introduces some protocols and criterions on the web heterogeneous information retrieval. In view of the importance and universality of Metadata Z39.50 XML in the practice, each is given one chapter to introduce the concepts the significance to information retrieval system structure their use in practice, current problems and development trend. Chapter 5 gives a systematic introduction on other usual protocols and criterions. Based on former analysis, chapter 6 gives a compare on the origin the purpose of planning application area system structure etc. of these standards. Chapter 6 can also be seen as the conclusion and deepening of the second part.The third part(chapter 7 included) summaries the theory and practice instruction significance of the paper, analyses the reason for the unsolved problems, and provides the outlook for further study.With the progress of time, the planning of standards is also changing. New standards are increasingly provided and used for practice, and old standards are consequentially out of data. Under current background, a research on the web heterogeneous information retrieval has an important sense. With the task going on, many industries can have a better understanding on how to choose the best standards for the interoperating of different data.