When I hear the word "massacre," I think of many people being killed in an incident that is unprovoked and unjustifiable.  This is not the way it was at the Boston Massacre, yet we use that name for it.  This is an example of perception and bias with regard to a historical event.

The massacre was not unprovoked.  There was a lot of animosty between soldiers and Bostonians.  Just before the massacre, people were throwing things (including rocks) at the British guards.  The guards may well have feared for their lives.  The massacre itself killed five people, which is a lot, but which does not reach the level of "massacre" by definition.

Perception and bias comes in because the British were the "bad guys" in our eyes.  Because of that, we see their actions as uniformly bad and the actions of the Patriots (including the Tea Party and the violence against government officials) as good.  We are biased in favor of our side and that strongly affects the way we look at historical events.

What does the Boston Massacre demonstarate about the perception and bias concerning an historical event ?

I think that the Boston Massacre can represent the power of image and how events can be manipulated to form public opinion.  At a time when there was significant discussion as to whether or not the Colonists should adopt a position of loyalism towards England or advocate the separation from the parent nation, patriots were actively involved in using the Boston Massacre as a way to galvanize public opinion in favor of separation and away from the Loyalist position.  Sons of Liberty leader Sam Adams was able to use his Committee of Correspondence as a way to move public support in favor of patriotic aims.  The very idea of being able to spin the event into a type of "Massacre" went very far in the Colonial mindset about how events were to be perceived.  The fact that the event was "spun" into a way to feed Patriotic bias and perception was an instant where the British found their actions manipulated by the ends of individuals who were savvy enough to understand that public perception is something to be molded and crafted out of specific events.  The so- called "Massacre" was something that Patriotic "spin doctors" were able to use to galvanize support and start the inevitable momentum towards an independence movement.