Dynamic aspects of documents of the Brazilian Web

The huge number and the textual nature of Web documents have created the need for search engines. In this kind of system the user´s queries are answered based on a static view of the whole or part of the Web. However, the Web is a dynamic system and its documents are inserted, changed and removed frequently, thus creating an inconsistency between the state of the Web and the static view of the documents of the search engine. We describe the dynamic aspects of the HTML documents of the Brazilian Web, namely the rate of insertion, change and removal of its documents, from the point of view of search engines. We also describe the tools we used to support this study. Whenever possible, we compare measures of the Brazilian Web with related measures of the World Wide Web. We show how the study of these aspects can be used in search engines to improve the quality of its services, in particular, aspects related to robots or spiders