We study two aspects of assurance services in electronic commerce. The first deals with the type(s) of evidential networks that will allow a professional accountant to provide assurance. Here, we develop an evidential network model for "WebTrust Assurance," a service being provided by the American Institute of Certified Public Accountants (AICPA) and the Canadian Institute of Chartered Accountants (CICA). Our model augments the AICPA/CICA approach and provides goals, subgoals and evidence relevant to the overall assurance to be provided. The aggregation of evidence and the resolution of uncertainties follow the belief-function approach.
Key words and phrases: assurance services , decision theory , electronic commerce , risk management , WebTrust