So subject trees contain a smaller portion of the web. However, the subject tree categories bring together lots of web sites on a topic. In a subject tree you may not find the specific piece of information you want, but what you do find is usually not trivial. A subject tree containing 600,000 sites. Simple searching of the 600,000 sites.
Small letters can be either small or captials.
When Yahoo finds nothing, Yahoo automatically passes the search to AltaVista and retrieves an AltaVista search. It contains more than 3,000 sites. Boolean searching is easy. A strength of this index is that each site listing is annotated. And related subject headings are given.