Author - enter the last name first followed by the first name. Be sure you spell the name correctly. Some databases require that you use the author s initials rather than the full name. Subject - a subject search will give you more references than a title search, but you must enter the subject exactly as it is used in the subject index, including dashes, or commas, or word order. This includes the use of thesaurus terms.
Many databases have a thesaurus specifically for that database only.
Keyword - a keyword search is the most comprehensive way to search for a topic. NEAR - is used to search for terms which are within a specified number of words of each other but they can be on either side. You will get rat or rats but you will also get rate, rated, ratio, ratios, ration, rather ratite, rattler, etc. Most databases provide a way to review you search history that will allow you to see the combination of terms you have searched with the number of references that were found. You can use these previous search sets to refine your search to be more specific or more general.