Events Calendar

USC's Homeland Security Center (CREATE) Monthly Seminar Series

Speaker: Dr. Stephen Hora, CREATE Director

Talk Title: “Median Aggregation of Distribution Functions”

Series: CREATE Monthly Seminar Series

Abstract: We are pleased to invite you to attend CREATE’s monthly seminar!


Abstract: When multiple redundant probabilistic judgments are obtained from subject matter experts, it is common practice to aggregate their differing views into a single probability or distribution. Although many methods have been proposed for mathematical aggregation, no single procedure has gained universal acceptance. The most widely used procedure is simple arithmetic averaging which has both desirable and undesirable properties. Here we propose an alternative for aggregating distribution functions that is based on the median cumulative probabilities at fixed values of the variable. It is shown that aggregating cumulative probabilities by medians is equivalent, under certain conditions, to aggregating fractiles. Moreover, the median aggregate has better calibration and sharpness properties than mean aggregation when the experts are independent and well calibrated.

To ensure that I order your lunch, please RSVP to calicchi@usc.edu. Please advise if you require a vegetarian option.

Hope to see you there!


Biography: Presenter: Stephen Hora serves as Director of CREATE (the National Center of Excellence for Risk and Economic Analysis of Terrorism Events) at the USC. He is a Research Professor of Industrial and Systems Engineering at the Viterbi School of Engineering and of Public Policy and Management at the Price School of Public Policy. He is an expert in decision and risk analyses with particular interest in the use of subject matter experts, statistical modeling, and the analysis of technological, natural, and environmental hazards.
During the past twenty-five years, Professor Hora's research has focused on the analysis of risks from technological hazards. Most prominent has been his research into the use of experts to quantify risk and decision models. The work spans a range from practical applications to the creation of theoretical foundations and entails being an active participate in designing and staging elicitation processes.

Host: Homeland Security Center @ USC (CREATE)

Location: Ronald Tutor Hall of Engineering (RTH) - 306

Audiences: Everyone Is Invited

Contact: Erin Calicchio