What counts as a primary source may differ from discipline to discipline, but for historical studies a primary source is an artifact that was created during the time period which is being examined. Primary sources may be newspapers, diaries, letters, or pamphlets; they can also be non-textual objects such as paintings, photographs, or a piece of clothing. Primary sources are important for historical study because they offer unique access to the time period which is being studied. This does not mean, however, that primary sources are without their own biases and limited perspectives. As such, they need to be carefully evaluated by asking questions such as "Whose perspective does this primary source represent?" or "For what purpose was this primary source created?"