Final answer:
Historians consider opinions to understand bias.
Step-by-step explanation:
Historians may want to consider opinions as well as facts reported by a source because the opinions may provide clues to the source's feelings and possible bias. This is important because sources can be influenced by their own beliefs and perspectives, which can shape the information they provide. By considering opinions, historians can better understand the context and potential biases of the source, allowing them to form a more accurate and comprehensive interpretation of the historical events.
Learn more about Examining opinions in historical sources