So what is bias from an appraiser’s perspective? Again, according to USPAP, bias is “a preference or inclination that precludes an appraiser’s impartiality, independence, or objectivity in an assignment. I’ve written about this many times in the past. An appraiser must always be impartial, independent and objective. Unbiased. The second we show bias, we throw all those characteristics – what makes appraisers unique and extremely important in the real estate valuation world – out the window.