What's in them?
Who writes them?
What do they look like?
Who reads them?
What are their advantages?
What are their disadvantages?
Popular: Inform and entertain the general public. Magazines like Time or Rolling Stone; or newspapers like the L.A. Times.
Scholarly: Disseminate research and academic discussion among professionals in a discipline. Journals such as Journal of Applied Communication Research. Usually peer reviewed or refereed.
Trade: Neither scholarly or popular sources, but could be a combination of both. Allows practitioners in specific industries to share market and production information that improves their businesses.
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