Many people casually describe a real estate appraisal as an “estimate of value.” While common, this language misrepresents what appraisal actually is and why professional judgment remains essential. An appraisal is not an estimate of a hidden or pre-existing number. It is a reasoned value opinion formed under conditions of uncertainty.

An estimate assumes that a true value already exists.  It can be approximated with better data or tools. Market value does not work that way. No single, correct value resides inside a property waiting to be discovered. Instead, market value reflects how typical buyers and sellers are most likely to behave.  This assumes a specific point in time, under specific conditions, with incomplete information.

Real estate markets involve people, not machines.  Therefore, uncertainty cannot be eliminated. Every sale is unique. Different buyers, financing terms, timing, motivations, and negotiations can produce different outcomes without anyone acting irrationally. A sale price shows what happened, not what had to happen.

This is why appraisers opine value.  They do not estimate it. A value opinion integrates data, analysis, experience, and judgment into a credible conclusion about probable market behavior. Data informs the process, but judgment drives it. No amount of automation, peer conformity, or form-filling can replace that responsibility.

USPAP reflects this reality.  It emphasizes credibility over accuracy. Credible appraisal practice requires transparent reasoning, appropriate scope of work, and professional accountability.  Nothing in USPAP calls for mechanical precision.

Understanding this distinction protects the integrity of the appraisal profession.  It also serves to clarify the appraiser’s role, and reinforces why judgment remains non-delegable in valuation practice.