Indexing of new or modified pages by just one of the major search engines can take months. Plus, researchers must analyze each information problem that comes their way and choose which tools are appropriate for solving it. And, even though the size of the Internet seems overwhelming, there is more information available in any major research library. Indexing is automatically created from the collected files. There is no selection criteria for the collection of files.
Subject directories are collections of many links on a topic.
Click here for more information about subject directories of particular interest to scholars and researchers . The following Web sites offer excellent information to help researchers choose the most appropriate search tools and use them effectively. It differentiates search indexes from subject guides and offers tips on when to use what. Highlight of the site is a detailed features table that explains Boolean syntax, phrase searching, truncation, and field searching, among other features, for several services. Information on coverage magnitude is also available.