Tom,
The general advice to submitting queries is to follow what the guidelines say. Some editors request a writing sample/clip or two and others don't.
If the market you're targeting the query to doesn't have it listed but you'd like to verify before sending (a good idea if you have any reservations), don't be afraid to give the editor or editorial assistant a quick call and ask. Keep it short and professional and don't pitch your article--just ask if they prefer samples/clips with the query submission.
Happy Writing & hope that helps,
Beth
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www.bethmorrow.com
www.writer-in-progress.blogspot.com--my take on the writing life
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