How Do You Challenge the Tax Appraisal Value of a Home Due to Declining Values?

Here is a timely question in Zillow Advice by a Zillow user named Coinhunter who asks from Seymour, TN:
How do you challenge the tax appraisal value of a home due to declining values?
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Source: http://www.zillow.com/blog/how-do-you-challenge-the-tax-appraisal-value-of-a-home-due-to-declining-values/2011/01/06/

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