Specialized Searches Other Good Places to Start Search engines are especially helpful if you know exactly what you're looking for.
Subject indexes work like a hierarchy or tree using subject headings.
First you find Science, then under that you choose Biology, then Genetics, etc. These are useful for browsing as well as finding just those web sites about a particular subject. The best Subject Guides have real people evaluating and choosing which web sites to include, deciding what catagory they should fall under, and describing them. Search Tools Chart for advanced searching techniques for many search engines. A helpful guide to different kinds of search tools with links to each.