“A column by Glenn Garvin on Dec. 20 stated that the National Science Foundation ‘funded …
Whether you're in the position of evaluating a writer's source material or finding your own, keep in mind the distinction between between primary and secondary sources, and use primary sources whenever possible. Think of these as raw material- the original wellspring of information.
— The Chicago Guide to Fact-Checking by Brooke Borel (37%)
I'm gobsmacked that there's an entire chapter devoted to sourcing that doesn't even define primary and secondary sources. Maybe I'm just being pedantic, but genealogy methods and citation texts drill these concepts into a person.