"Primary or Secondary? The Changing Status of a Source "While the definitions provided above seem fairly straight-forward, it is not always easy to determine whether a particular text is a primary source or a secondary source. This is because the status of a source as primary or secondary depends not on how old the source is, but rather on the historical question you are asking. For example, if you are writing about the reign of Julius Caesar (100-44BCE), Suetonius's Lives of the Twelve Caesars, written in the early second century CE, would be a secondary source because Suetonius was not a witness to the events he describes. If, however, you are writing about the debates among second-century Romans about the use and abuse of imperial power, Suetonius's work would be a primary source. Thus, the status of a source as primary or secondary depends on the focus of your research."
Examples of Secondary Sources:
"Books, articles, documentary films [that analyze and interpret the historical event or issue]."