Searching online can be both beneficial and frustrating. You may find vast amounts of information, or you may not find the kinds of information you're looking for. Searching online will provide you with a wealth of information, but not all of it will be useful or of the highest quality.

The internet is a superb resource, but it doesn't contain all the information that you can find at a library or through library online resources. You should not limit your search to what is on the Internet, and you cannot expect search engines to find everything that is on the Web.

The Internet is a complex and ever-evolving place. New sites and media are not automatically found by search engines. Indexing is the term for the process whereby webcrawlers find and include new pages and other media in their search results. However, search engines still only index a fraction of what is available on the Internet and not all of it is up to date. Search engines may only "crawl" sites (or revisit them for purposes of indexing) every month or less; information that has been updated since that time will be invisible to the search engines.

Finally, search engines don't always search the entire page; many search engines will only index the first 100 to 500k of each page. So there might be valuable information that is being overlooked by a search engine, even in pages that are indexed.

Additionally, not all of the information located on the Internet can be found via search engines. Researchers Chris Sherman and Gary Price call this information the "invisible Web" (another name that is frequently used is the "deep Web"). Invisible Web information includes certain file formats, information contained in databases, and pages omitted from search engines.

With this in mind, knowing a few search strategies and hints can make the search more profitable. This guide provides information on the different ways of locating material online, including using search engines, searching the invisible Web, and using Web directories.