A tax assessment is a government assigned figure that property taxes are based on.  In some "ad valorem" states an assessment is related to market value and it is determined or established by analyzing comparable sales and cost data.  In other states, like Nevada, assessed values are based entirely on cost estimates.  An assessed value is usually a portion of a property's "taxable value" which is the Assessor's estimate of full value.  In a large metropolitan area an Assessor often uses "mass appraisal" techniques / computer models to assign taxable values to each property.  Assessed values, taken from the taxable value estimated, are multiplied by tax rates to determine their taxes. 

While things are changing in the Nevada real property tax world the changes are not always fair for everyone.

When you don't think the valuation that you paid for is accurate you can spend some time and effort yourself to validate the results.

Most appraisal assignments direct the appraiser to form an opinion of the market value of a specific property. If you are familiar with appraisal definitions you know that most market value definitions indicate that market value is the “most probable price” that a market participant will pay for a property. So in most instances appraisers have to consider value as an anticipation of future benefits.

Appraisers try to compare properties using uniform measurements, and area is an important physical characteristic of a property compared when land or buildings are analyzed.  Land area comparisons appear to be simplistic, until you consider why parcels sizes vary.

The property tax disputes process demands that you act quickly if you want to appeal.  An appraisal is usually required, but you need to determine whether you can actually save money given costs.  The common sense of falling market conditions falls on deaf ears at the tax hearing, and logic does not always prevail.