When evaluating primary or secondary sources, the following questions can help you evaluate the nature and value of material:
Ultimately, all source materials of whatever type must be evaluated and critically assessed when determining if you want to use it in your paper or project.
Whether something is a primary or secondary source often depends upon the topic and its use.
For example, a biology textbook would be considered a secondary source in the field of biology, since it describes and interprets the science and makes no original contribution to the discipline.
On the other hand, if the research topic is science education and the history of textbooks, textbooks could be used a primary sources to look at how they have changed over time.