Key points are not available for this paper at this time.
Kathryn M. Chaloner, George T. Duncan, Assessment of a Beta Prior Distribution: PM Elicitation, Journal of the Royal Statistical Society. Series D (The Statistician), Vol. 32, No. 1/2, Proceedings of the 1982 I.O.S. Annual Conference on Practical Bayesian Statistics (Mar. - Jun., 1983), pp. 174-180
Chaloner et al. (Tue,) studied this question.