Shreya's is working on a project about the transcontinental railroad. One of her sources is an article by a historian at Stanford University that analyzes the impact of railroads on the growth of the United States.

Which descriptions best characterize this source? Select three options.

biased

credible

factual

opinion

secondary

This course can be characterized as credible, factual, and secondary.

It is credible because it is written by an academic, a history expert who is associated with a prestigious university. It is factual because the author is examining actual events which took place in history ("the impact of railroads on the growth of the United States"). It is a secondary source because it is the work of someone writing about past events retrospectively, as opposed to primary sources which are first-hand documents (like letters, pieces of legislation, speeches, etc.).