Soliciting engineering judgments on building collapse fragility using structured elicitation process
Kishor Jaiswal, U.S. Geological Survey Golden CO/Synergetics Inc.
Thursday, May 9, 2013 at 10:30 AM
- Building 3, Room 3240 (main USGS conference room)
- Mehmet Celebi
Pooling engineering input on earthquake building vulnerability through an expert judgment elicitation process requires careful deliberation. Both empirical and analytical/experimental approaches have been employed in the past to analyze structural collapse fragilities. In this presentation, I will demonstrate the use of a structured elicitation process proposed by Cooke (1991), hereafter referred to as Cooke's approach, for eliciting judgments on structural collapse fragility of selected building types. Cooke's approach works on the principle of objective calibration scoring and hypothesis testing that is used in classical statistics. This performance-based scoring system reflects the combined measure of an expert's informativeness about the problem under consideration, and his ability to express his true belief about uncertainties associated with his assessments. These attributes are measured using the calibration and an information score. The calibration score measures the 'statistical accuracy' whereas an information score measures the level of sharpness of the information, that is, on the concentration of personal probability distributions in comparison to the uniform (or log-uniform) background distributions. Drawing from my own experience of conducting two such elicitations in recent past, I will discuss several key facets associated with the process, such as identifying experts, constructing seed and target questions, eliciting expert judgments, and finally combining multiple judgments in order to construct building typology-specific generic collapse-fragility curves.