What is appraisal bracketing?

According to the Dictionary of Real Estate Appraisal, 5th Edition, Appraisal bracketing is a process in which an appraiser determines a probable range of values for a property by applying comparative analysis techniques to data such as a group of sales. The array of comparable sales may be divided into three groups -those superior to the subject, those similar to the subject, and those inferior to the subject. The sale prices reflected by the sales requiring downward adjustment and those requiring upward adjustment refine the probable range of values for the subject and identify a value range (i.e., a bracket) in which the final value opinion will fall.