The good folks at Vanderbilt University have put today a concise video about the differences between popular and peer-reviewed periodicals.
Watch this short video from the great folks at North Carolina State University Libraries for a clear explanation of the peer-review process.
Look it up in Ulrich's Global Serials Directory! Search the title and then check the "Refereed" colomn to find out whether the title is a peer-reviewed journal.
So, you used the scholarly/peer-reviewed filter in your search. All of the results qualify as peer-reviewed sources, right? Wrong.
Book reviews, columns, editorials, letters to the editor, brief news items don't count as peer-reviewed articles.
There are some very basic things you should think about when you evaluate information. You probably use these criteria without realizing it, but it's good to see them spelled out.
Who wrote or created the item? Is this person an expert? What credentials does this person have?
Is the item meant to inform, entertain, or persuade?
Does the item give surface information or does it delve deeply into a topic? Depending on your information need, an item may not be suitable if it gives you too much or too little information.
How reliable is the source? Is it an anonymous blog, an articles in an established journal? Does it cite sources, or are statistics and facts included with no information about where these came from?
When was the item created? Outdated information isn't helpful outside of a historical context.