Neil and Mell's responses above are correct. To clarify where the 'illegal' part of the refusal to provide work samples, let me say this: Most states have at least one law or regulation on their books that specifies that the Uniform Standards of Professional Appraisal Practice (USPAP) represents the minimum standard of conduct for a licensed or certified appraiser in that state. Thus, a violation of USPAP would be against the law and would subject the appraiser to discipline from the state appraisal board.
The violation that is being alluded to is the Confidentiality section of the Ethics Rule, which prohibits an appraiser from disclosing confidential information or the results of an assignment to anyone other than the client, those parties specifically authorized by the client, state appraisal boards, parties authorized by due process of law, and the peer review boards of one of the professional appraisal organizations. And no, the review staff at a lender is not one of those parties.
Then there is also the recently enacted Gramm-Leach-Bliley bill, which also protects confidential information under certain circumstances.
Bottom line here is that a consumer isn't really goning to learn much of anything about an appraiser from looking at work samples. The samples they get might not be indicative of the appraiser's everyday work product, might not be indicative of how the appraiser handles unusual problems (especially if the appraiser sends in reports covering simple properties), and might not even be the appraiser's own work product. The only way to find out how an appraiser performs is either to try them out, or ask for references (and check them).
George Hatch