  Subjective Bayesian prior distributions elicited from experts can be
aggregated together to form group priors. This paper compares aggregated priors
formed by Equal Weight Aggregation, the Classical Method, and the Sheffield
Elicitation Framework to each other and individual expert priors, using an
expert elicitation carried out for a clinical trial. Aggregation methods and
individual expert prior distributions are compared using proper scoring rules
to compare the informativeness and calibration of the distributions. The three
aggregation methods outperform the individual experts, and the Sheffield
Elicitation Framework performs best amongst them.
