Some Basic Comments about Searching Tools
Types of Search Tools
There are basically two types of search engines.
Search Engines
First, there are those that operate word search technologies. This results in a list of sites that happened to have your "key word" in them. Now, the technology used to accumulate and present these lists is pretty sophisticated. Programs call "spiders" and "crawlers" go out on the web, (sending things called "bots"), to locate sites which contain specified criteria. An index is made of their findings. Then, when you place a key word query, a retrieval program using sophisticated formulas, (mathematical algorithms), finds sites within the index and displays them according to another sophisticated formula, (mathematical algorithm). The ability of these search engines to do the job depends on both the "spider" and the "retrieval program". They are not alike and you will do well to check out several in your search.
Directories
Then, there are those that operate using a "directory" system that requires someone, (usually a human), to sort various sites into particular categories. Obviously, this takes some time and effort. The quality of the list depends on the individual or company doing the categorizing. Since many of these companies are being paid to place names among their "directories", you should be careful about bias in the listings.
Meta Search Tools
A meta search tool is nothing more than a program that, like an agent, sends your request to a number of search engines. This saves you time in having to check each one.
However, since each search engine uses its own logic and method for searching for results, it isn't always possible to perform some of the more "advanced" searches that involve phrases or sophisticated boolean logic.
For more information.....
Check out The Spider's Apprentice
My Favorite Searching Tools
ZDNet's Search IQ This is OFTEN my starting place!
Best Search Tools, InfoPeople (The people at UCLA all seem to like this one....I didn't find it particularly useful...probably because it goes to Northern Lights which, if you don't pay to subscribe, isn't very productive.)
I use this one very frequently. Don't know why. It just seems to serve my needs well. An alternative I use to metacrawler I use this Search engine to find sites through a word search. It will often locate sites other engines will not. However, to use it effectively, you need to know the key words to use! This is really a web directory, much like a card catalog at your library except that the listings often pay Yahoo for the priviledge of being in the catalog. Nonetheless, the site is comprehensive and includes many government and other public information which you can find without knowing key words! This isn't really a search engine at all but takes you to a list of other search engines such as Lycos and Excite. I use these when the above fail.