Zillow Advice: Market Conditions - How was Zillow Home Value Index calculated? http://www.zillow.com/advice-thread/How-was-Zillow-Home-Value-Index-calculated/372595/ Zillow Advice | Zillow Real Estate READ this entire&nbsp;article ... http://www.zillow.com/advice-thread/How-was-Zillow-Home-Value-Index-calculated/372595/ <a href="http://www.zillow.com/wikipages/What's-the-Zillow-Home-Value-Index/">READ this entire</a>&nbsp;<a href="http://www.zillow.com/wikipages/What's-the-Zillow-Home-Value-Index/">article</a> on what a ZIllow Home Index is.<br/><br/>The HOME INDEX depends on how much data you have. Its exactly the same data appraiers, banks, lenders, etc use&nbsp;- Zillow just shows it for free. <br/><br/>MORE data, BETTER accuracy, and vice versa. URBAN areas better, rural areas -&nbsp;not so much. SAME accuracy as appraisal data as its the same data. <br/><br/>Now thats for SOLD data. Active data is obtained from local and national MLS sources. MLS data must be opted in by the owner/listing agent of the home for sale, at some point, for Zillow to use it. <br/><br/><br/><br/> Tue, 26 Oct 2010 16:13:00 GMT http://www.zillow.com/advice-thread/How-was-Zillow-Home-Value-Index-calculated/372595/ 2010-10-26T16:13:00Z