Effective online research requires knowing available search tools, understanding how they work, and being able to use them to evaluate results. The internet contains large amounts of easily accessible information but not everything and results can be frustrating. Anyone can publish online so web sources may lack author qualifications and biases while print is more regulated. Search engines use keywords to return sponsored and algorithmic results about page content and links. General search engines only access the visible web while specialized tools reach the invisible web. Boolean operators and quotation marks allow refining searches. Sources must be evaluated for purpose, authority, currency, and corroboration to determine reliability for a research need.