I would definitely follow USPAP S 3 and 4. You can just go down through the standard to make sure you include required items. appraisal review methodology is entirely a function of the intended use and users. You can decide what it is you will be commenting on, what you will look for, and how you will derive your comments, the scope of work is critical . Spend some time with it. Go back to it and revise it as you perform the review. Any comment you make as to the quality of another appraiser's work product immediately defines your review as a USPAP appraisal review. Whether you opine as to your own value conclusion is not the test . If you do opine as to the credibility of the value, that comment, agree or disagree is considered an appraisal. You should consider carefully how you want to approach this. If your issues with the other report are in reference to using data and methods that the assessing methods don't use, I don't think that will likely punch holes, as as many assessing conditions are not reflective of actual market activity. If you are going that route spell it out in the scope. If you comment on the credibility of the result, it would behoove you to state that the appraisal has method deficiencies which likely lead to results which lack credibility. Then I would simply observe the difference between the report's conclusion, and the assessed value. Make no statement as to agreement or disagrement just note the difference. You can probably get away with using the assessment as your appraisal, but wording this way secures it. Include the assessment appraisal in the review by reference. When in court, try to limit your responces about the other report to what you include in the review. You dont wanty to perform a review on the stand. Hit every violation of USPAP, regardless of it's insignificance. Every adjustment must have data supporting it, or well reasoned explanation. Statements that adjustments were not required also require this kind of support. Remember the certificate.