Subjective Probability Elicitation: The Effect of Congruity of Datum and Response Mode on Performance

Accountants are increasingly being asked to express their opinions in terms of subjective probabilities. For example, auditors are now asked in firm training sessions to express their subjective probabilities concerning risk levels in audit tasks. Interval financial statements provide a potential harbinger of subjective probability situations wherein accountants will have to express their feelings about the facts presented or use their subjective probabilities as one means of evaluating the subjective expressions of others. And, as consultants, accountants familiar with decision making under uncertainty must often obtain subjective probabilities from client personnel. Each of these uses of subjective probability may increase in importance in the future as the use of formal decision approaches becomes more widespread. Consequently, accountants will need to be aware of various possible methods of obtaining subjective probabilities, and their comparative advantages or disadvantages. The research results reported here represent an attempt to test existing theories about different methods for obtaining subjective probabilities. These tests are necessary because the theories have not been subjected to testing within the specific confines of elicitation technique comparison. The psychological scaling theory and the congruity theory