(a)

be aware of, understand, and correctly employ those recognized methods and techniques that are necessary to produce a credible appraisal;

Comment: This Standards Rule recognizes that the principle of change continues to affect the manner in which appraisers perform appraisal services. Changes and developments in the real estate field have a substantial impact on the appraisal profession. Important changes in the cost and manner of constructing and marketing commercial, industrial, and residential real estate as well as changes in the legal framework in which real property rights and interests are created, conveyed, and mortgaged have resulted in corresponding changes in appraisal theory and practice. Social change has also had an effect on appraisal theory and practice. To keep abreast of these changes and developments, the appraisal profession is constantly reviewing and revising appraisal methods and techniques and devising new methods and techniques to meet new circumstances. For this reason, it is not sufficient for appraisers to simply maintain the skills and the knowledge they possess when they become appraisers. Each appraiser must continuously improve his or her skills to remain proficient in real property appraisal.

(b)

not commit a substantial error of omission or commission that significantly affects an appraisal; and

Comment: An appraiser must use sufficient care to avoid errors that would significantly affect his or her opinions and conclusions. Diligence is required to identify and analyze the factors, conditions, data, and other information that would have a significant effect on the credibility of the assignment results.

(c)

Comment: Perfection is impossible to attain, and competence does not require perfection. However, an appraiser must not render appraisal services in a careless or negligent manner. This Standards Rule requires an appraiser to use due diligence and due care.