This follows from my earlier thread, "Factual vs Methodological Determinations" 6/10/99 # 593. Kerry posed an important question (6/13 #596), "If we were to name the 5 most common mistakes plant appraisers make, what would those 5 be?"

I don't see a lot of other appraisers' work, but I've listened to the discussions over the years - especially here at KnotHole - and read the articles that try to address plant appraisal problems. I'd guess that plant appraisers tend to think their mistakes (or the other guy's mistakes) are in technique. Poor measurement or misapplication of a rating factor for example. I'd suggest that the most common mistakes are more conceptual than that and such conceptual mistakes result in technical inconsistencies which can be characterized as mistakes.

So here's my opinion on the five most common mistakes:

1. Failure to understand that value is NOT a physically measurable characteristic.

2. Failure to understand that value is NOT single, uniform and unchanging concept.

For a good treatment see: Appraisal Institute, 1992. The Appraisal of Real Estate, 10th Ed. Chicago: Appraisal Institute, 768pp. Chapter 2, "The Nature of Value."

3. Following directly from #2, failure to define value in each appraisal. (See # 4 following.)

4. Failure to define the appraisal problem. This definition includes (in addition to the definition of value) considerations of value to whom (the beneficiary), the date of value, the purpose and use of the appraisal (they are not the same) and limiting conditions.

#3 and #4 are required steps in the appraisal process under the Uniform Standards of Appraisal Practice (USPAP), Standards Rule 1-2, b and a respectively. (https://www.appraisalfoundation.org/uspap/toc.htm) />
For a good treatment of defining the appraisal problem see Appraisal Institute, p. 72.

5. Concentrating on technique rather than understanding the appraisal problem. The purpose of any appraisal in the most basic sense is to answer the question asked by the client. Appraisal is an aid to decision makers (Kinnard, 1971.) Appraisal should concentrate on answering that question in terms that are descriptive and explanatory. Appraisal should not masquerade as a precise and single answer to every question that is grounded in perfect technique.