In order to develop your knowledge on a historical event, you must research information from different historical sources. Whether you learn the information from a primary or a secondary historical source, it is still altered from the informant’s point of view and their interpretation. Person A can see something that person B could not see. For example: when you flash an optical illusion to two people, there is a chance they will say they saw the same thing but most likely, they will say they saw different things. When looking for information on a historical event, using multiple sources can help you develop your own point of view for the event. (Source: Optical illusion)