A primary source:

• is an original work that first presents an idea or reserach results, or
• is a firsthand account of an event or phenomenon, or
• was created at the time being studied, and relates directly to the topic being studied

Examples of primary sources include:

• data from experiments
• diaries
• statistics
• news articles (print, radio, tv, or online) that report contemporary events
• works of art or architecture
• archaeological artifacts
• interviews

A secondary source:

• provides analysis, interpretation, commentary, and/or opinion on primary source material

Examples of secondary sources include:

• journal articles that discuss the results of research
• reviews
• books that analyze or interpret primary sources
• documentary films