Article: Automated Analysis: How Accurate are the Results?

[Dan]

You can view the page at http://www.cyburbia.org/content.php?...re-the-results

[ColoGI]

You can view the page at http://www.cyburbia.org/content.php?...re-the-results

It's all about the premise: if your premise is "I'll only use this tool" then the tool is not good enough. If your premise is "its a good place to start" then you are all set.

[azmodela]

"Two homes of a similar size and age, on equally-sized lots in the same neighborhood, should have more or less equal value. On the face of it, this seems like a reliable statement and is the basis for several home value websites such as Realtor.com or Zillow.com. These services rely on such basic assumptions in developing algorithms to calculate expected home values based only on data from sources such as assessment roles (providing information such as lot and building size) and recent home sales in the vicinity. But what about other factors not apparent in the data? What if one home is a beautifully restored 1900’s Craftsman bungalow in a quiet neighborhood across from a park, while the other is a poorly maintained and nondescript ranch house on a four-lane arterial surrounded by industry? While obvious to us, the computer cannot “see” these differences and will suggest similar values for the homes, significantly over- or under-estimating their value. " Doesn't sound like they're in the same neighborhood. But, this article is written to justify the services you offer and Zillow or Realtor.com impede on the services that the average home owner might peruse. I would expect that Zillow or Realtor.com would pick up on the two completely different examples that you provided and would generate a good starting point for the estimation of value. Remember, starting points can go up or down.

[Cardinal]

"But, this article is written to justify the services you offer and Zillow or Realtor.com impede on the services that the average home owner might peruse. I would expect that Zillow or Realtor.com would pick up on the two completely different examples that you provided and would generate a good starting point for the estimation of value. Remember, starting points can go up or down.

True, market analysis is one of the services I provide. Still, the article is meant to caution people about relying too heavily on the kinds of numbers generated by sites like Zillow and from services like ESRI or Claritas. The opportunity for error is significant, especially as you move from trying to assess a metropolitan area to a neighborhood to a site. Planners often fail to question the numbers they receive, whether they download a report themselves or if it comes from their consultant. But the decisions they make and strategies they recommend are often influenced by those same reports. Shouldn't people seek more reliable information?