Home Value: What the Web Can and Can't Tell You

When it comes to researching home value, there's no shortage of information. The Web brims with home value tools. And people use them. In a typical month during house-hunting season, real-estate websites -- including this one -- get more than 50 million unique visitors.

So-called "automated value tools" can tell you a lot about a property, including its sales history, estimated market value and what comparable homes have sold for. But to get the most from online home value sites, it helps to understand the limitations of home value estimators and calculators.