This document discusses evaluating information sources for academic essays. It defines primary sources as original research, secondary sources as reporting on primary sources, and tertiary sources as summarizing primary and secondary sources. Primary sources are the best to use in academic essays when facts or research are needed. Secondary sources can be useful when another's interpretation is required. Tertiary sources provide background but should not be the main sources. The document also discusses determining the credibility of sources based on the author, publisher, purpose, accuracy, and context.