Most people tend to want to find a specific, useful piece of information or a few good sources of high quality information quickly. Key words should describe the search subject as clearly and uniquely as possible. Enclose the phrase in quotations so the search engine retriev es only those documents that contain your given phrase. If this doesn't give you good search results, think of two to three words that unambiguously describe the subject. Check your spelling and capitalization.
Computers are dumb.
They retreive only what you type in. Try alternative key words or synonyms if the key words you are using do not produce the results you expect. Change the order of execution, in other words, switch the order of the key words. Most search engines evaluate Boolean expressions such as AND, OR, and NOT in order from left to right. Begin with the most important key word first.