When studying history, asking questions and checking other sources will improve one's perspective. What other awareness is necessary?

When studying history, asking questions and checking other sources will improve one's perspective. The other awareness necessary is "To realize all writers and reporters have some bias of culture, geography, economics or politics".

Explanation:

History has been documented since the dawn of civilization, it is necessary to look into the main historical records and comprehend each perspective. Ability to understand history means not to be biased with your understanding base, each era has a justification why these events had occurred. Each writer has one or the other bias and this has affected the activities they write. Thus when reading books a viewer should take this into account.