AVM's  (Automated Valuation Models)

AVM's utilize sales data, property data characteristics, (such as bedrooms, baths, half-baths, year built, condition, grade, stories, topography), influence factor, lot size, gross living area, land and improved assessed values, land use codes, and various other secondary vectors relative to the physical property to generate valuations.

Know that AVM's deal only with data; they do not and cannot 'know' what interior or exterior remodeling has been completed, what landscaping is in place, etc. as an Appraiser would, unless that information is already on the Tax Assessor rolls.