The answers should be much more on target than with simple addition. Once you've mastered adding, subtracting and multiplying, you can combine symbols to easily create targeted searches. Practically all of the major search engines support this basic approach. WebCrawler Yahoo AltaVista is a little unusual in that it has automatic phrase detection. Snap and Yahoo are unusual in that they are primarily directories, which are built by humans.
Editors list sites by category, and they usually give each site a short description.
This means that when you search at a directory, you are first shown matching web sites . After that, or if there are no matching web sites at all, you are then shown matching web pages that come from search engine listings. You can still use this basic approach at directories, despite them being slightly different from search engines that crawl the web. All rights reserved.