The Experts below are selected from a list of 327 Experts worldwide ranked by ideXlab platform
Roger Cooke - One of the best experts on this subject based on the ideXlab platform.
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Interpretation and Analysis of Projected Ice Sheet Contributions from a Structured Expert Judgement
2020Co-Authors: Willy Aspinall, Roger Cooke, Bob Kopp, Jon Bamber, Michael OppenheimerAbstract:<p>Despite considerable advances in process understanding, numerical modeling and the quality of the observational record of ice sheet contributions to sea level rise (SLR) since the last IPCC report (AR5), severe limitations remain in the predictive capability of numerical modeling approaches. In this context, the potential contribution of the ice sheets remains the largest uncertainty in projecting future SLR beyond mid-century. Various approaches, including Monte Carlo ensemble emulator simulations, probabilistic or plausibility methods, and Semi Empirical Models have been used in attempts to address these limitations. To explore and quantify the uncertainties in ice sheet projections since the AR5, a Structured Expert Judgement (SEJ) elicitation &#8211; involving 23 Experts from North America and Europe - was undertaken in 2018; this allowed us to derive a numerically-formalised pooling of cogent uncertainty Judgements.</p><p>The results of the SEJ indicated that estimates, particularly for probabilities beyond the likely range used in the AR5 (i.e. 17th-83rd percentile), have grown since the AR5. The SEJ results indicated a 5% probability that global mean sea level could exceed 2 m by 2100, for a business-as-usual temperature scenario, with the ice sheets contributing 178 cm. The study elicited contributions for three processes - ice dynamics, accumulation and runoff - for each of the three ice sheets covering Greenland, West and East Antarctica. Here, we investigate how these three main physical processes influence the long upper tails in the probability density functions for the integrated contributions of each ice sheet. &#160;To interpret the findings, we draw on process-based rationales provided by the Experts, which relate ice sheet SLR contributions to ocean and atmospheric forcing and to internal instabilities, and discuss our higher total SLR estimates in relation to earlier studies.</p>
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Expert Judgement for dependence in probabilistic modelling a systematic literature review and future research directions
European Journal of Operational Research, 2017Co-Authors: Christoph Werner, Roger Cooke, Tim Bedford, A M Hanea, Oswaldo MoralesnapolesAbstract:Many applications in decision making under uncertainty and probabilistic risk assessment require the assessment of multiple, dependent uncertain quantities, so that in addition to marginal distributions, interdependence needs to be modelled in order to properly understand the overall risk. Nevertheless, relevant historical data on dependence information are often not available or simply too costly to obtain. In this case, the only sensible option is to elicit this uncertainty through the use of Expert Judgements. In Expert Judgement studies, a structured approach to eliciting variables of interest is desirable so that their assessment is methodologically robust. One of the key decisions during the elicitation process is the form in which the uncertainties are elicited. This choice is subject to various, potentially conflicting, desiderata related to e.g. modelling convenience, coherence between elicitation parameters and the model, combining Judgements, and the assessment burden for the Experts. While extensive and systematic guidance to address these considerations exists for single variable uncertainty elicitation, for higher dimensions very little such guidance is available. Therefore, this paper offers a systematic review of the current literature on eliciting dependence. The literature on the elicitation of dependence parameters such as correlations is presented alongside commonly used dependence models and experience from case studies. From this, guidance about the strategy for dependence assessment is given and gaps in the existing research are identified to determine future directions for structured methods to elicit dependence.
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Expert Judgement and uncertainty quantification for climate change
Nature Climate Change, 2016Co-Authors: Michael Oppenheimer, Christopher M Little, Roger CookeAbstract:Expert Judgement is often used to assess uncertainties in model-based climate change projections. This Perspective describes a statistical approach to formalizing the role of Expert Judgement, using Antarctic ice loss as an illustrative example. Expert Judgement is an unavoidable element of the process-based numerical models used for climate change projections, and the statistical approaches used to characterize uncertainty across model ensembles. Here, we highlight the need for formalized approaches to unifying numerical modelling with Expert Judgement in order to facilitate characterization of uncertainty in a reproducible, consistent and transparent fashion. As an example, we use probabilistic inversion, a well-established technique used in many other applications outside of climate change, to fuse two recent analyses of twenty-first century Antarctic ice loss. Probabilistic inversion is but one of many possible approaches to formalizing the role of Expert Judgement, and the Antarctic ice sheet is only one possible climate-related application. We recommend indicators or signposts that characterize successful science-based uncertainty quantification.
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Expert Judgement assessment quantifying uncertainty on thin ice
Nature Climate Change, 2013Co-Authors: Roger CookeAbstract:The contribution of ice sheets to sea-level rise still has large uncertainties that are yet to be quantified.
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quantifying scientific uncertainty from Expert Judgement elicitation
2013Co-Authors: Wp Aspinall, Roger CookeAbstract:Most scientists would like to see scientific advice used more in government decision-making and in all areas of public policy where science is salient, and many would welcome the opportunity to sit on Expert review panels or scientific advisory committees. When it comes to taking such decisions in many areas of hazard and risk assessment, the traditional committee approach still holds sway. Often in a committee setting, however, the role of scientific uncertainty is not an item on the agenda, and seldom a prominent component of the discussion. But misunderstanding its importance or misstating its extent will contribute to poor decisions. The slow, deliberative committee process, seeking a wide range of opinions with majority voting on outcomes, offers some parallels with the scientific process itself, but only in as much as a show of hands can equate to strength of argument. But as a means of gathering Expert opinion it is inadequate under many conditions, such as an urgent civil emergency arising from an incipient natural disaster such as a hurricane or volcanic eruption – situations demanding prompt scientific advice.
Willy P Aspinall - One of the best experts on this subject based on the ideXlab platform.
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anticipated impacts of brexit scenarios on uk food prices and implications for policies on poverty and health a structured Expert Judgement approach
BMJ Open, 2020Co-Authors: Martine J Barons, Willy P AspinallAbstract:Introduction Food insecurity is associated with increased risk for several health conditions and with poor chronic disease management. Key determinants for household food insecurity are income and food costs. Whereas short-term household incomes are likely to remain static, increased food prices would be a significant driver of food insecurity. Objectives To investigate food price drivers for household food security and its health consequences in the UK under scenarios of Deal and No-deal for Britain’s exit from the European Union. To estimate the 5% and 95% quantiles of the projected price distributions. Design Structured Expert Judgement elicitation, a well-established method for quantifying uncertainty, using Experts. In July 2018, each Expert estimated the median, 5% and 95% quantiles of changes in price for 10 food categories under Brexit Deal and No-deal to June 2020 assuming Brexit had taken place on 29 March 2019. These were aggregated based on the accuracy and informativeness of the Experts on calibration questions. Participants Ten specialists with Expertise in food procurement, retail, agriculture, economics, statistics and household food security. Results When combined in proportions used to calculate Consumer Price Index food basket costs, median food price change for Brexit with a Deal is expected to be +6.1% (90% credible interval −3% to +17%) and with No-deal +22.5% (90% credible interval +1% to +52%). Conclusions The number of households experiencing food insecurity and its severity is likely to increase because of expected sizeable increases in median food prices after Brexit. Higher increases are more likely than lower rises and towards the upper limits, these would entail severe impacts. Research showing a low food budget leads to increasingly poor diet suggests that demand for health services in both the short and longer terms is likely to increase due to the effects of food insecurity on the incidence and management of diet-sensitive conditions.
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anticipated impacts of brexit scenarios on uk food prices and implications for policies on poverty and health a structured Expert Judgement approach
arXiv: General Economics, 2019Co-Authors: Martine J Barons, Willy P AspinallAbstract:Food insecurity is associated with increased risk for several health conditions and with poor chronic disease management. Key determinants for household food insecurity are income and food costs. Whereas short-term household incomes are likely to remain static, increased food prices would be a significant driver of food insecurity. To investigate food price drivers for household food security and its health consequences in the UK under scenarios of Deal and No deal for Brexit . To estimate the 5\% and 95\% quantiles of the projected price distributions. Structured Expert Judgement elicitation, a well-established method for quantifying uncertainty, using Experts. In July 2018, each Expert estimated the median, 5\% and 95\% quantiles of changes in price for ten food categories under Brexit Deal and No-deal to June 2020 assuming Brexit had taken place on 29th March 2019. These were aggregated based on the accuracy and informativeness of the Experts on calibration questions. Ten specialists in food procurement, retail, agriculture, economics, statistics and household food security. Results: when combined in proportions used to calculate Consumer Prices Index food basket costs, median food price change for Brexit with a Deal is expected to be +6.1\% [90\% credible interval:-3\%, +17\%] and with No deal +22.5\% [+1\%, +52\%]. The number of households experiencing food insecurity and its severity are likely to increase because of expected sizeable increases in median food prices after Brexit. Higher increases are more likely than lower rises and towards the upper limits, these would entail severe impacts. Research showing a low food budget leads to increasingly poor diet suggests that demand for health services in both the short and longer term is likely to increase due to the effects of food insecurity on the incidence and management of diet-sensitive conditions.
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Expert Judgement and re elicitation for prion disease risk uncertainties
International Journal of Risk Assessment and Management, 2012Co-Authors: Michael G Tyshenko, Roger Cooke, Willy P Aspinall, Susie Elsaadany, Tamer Oraby, Shalu Darshan, Angela Catford, Daniel KrewskiAbstract:Much uncertainty surrounds transmission of transmissible spongiform encephalopathies (TSEs) through blood and blood derived products. A first Expert elicitation with 14 Experts was conducted in March 2008, and a second re-elicitation involving 11 Experts was held a year later in March 2009. Both Expert groups were calibrated using a series of seed questions for which values are known, and then were asked to provide their individual Judgements on a set of seven target questions for which values are not known or have not been determined through conventional research. Questions dealing with uncertainty of TSE prevalence, genotype effects, susceptibility, and infectivity were answered by the Experts. Elicitation can be used to obtain quantitative values for parameters affecting prion uncertainty gaps. We show that the method is amenable to re-elicitation over time allowing refinement of Expert opinion as new knowledge becomes available for improved risk assessments where data gaps continue to exist.
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Expert Judgement and the montserrat volcano eruption
1998Co-Authors: Willy P Aspinall, Roger CookeAbstract:A structured procedure for eliciting Expert Judgement has been used for the first time in a volcanic crisis for hazard assessment and ris k management.
Bruce Crawford - One of the best experts on this subject based on the ideXlab platform.
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Expert Judgement in Pharmacoeconomic Studies
PharmacoEconomics, 2000Co-Authors: Christopher Evans, Bruce CrawfordAbstract:Research in the field of pharmacoeconomics has increased substantially during the past decade. Much of this research has been on the design and analysis of data concerning the relative merits of one drug or device compared with another in terms of costs and effects. Concomitant with these evaluations has been the development of guidelines for the conduct of economic evaluations in several countries. However, despite an increase in research, little attention has been paid to how different study designs may influence the results of a study. The use of Expert Judgement in decision analytic modelling is one area where design issues may influence the findings of a study. This issue is examined for the case of modified Delphi and Delphi panels. Although the use of Expert opinion in modelling studies seems to be widespread, there is little consistent application, understanding or reporting of the techniques used. In particular, the definitions of techniques vary between studies, the criteria for determining when consensus is reached vary, and the reporting of these criteria is absent. Future studies using Expert Judgement should be more aware of the controversies surrounding the issue and provide more reporting of the techniques used. It is proposed that future validation exercises may assist researchers in determining the most appropriate application of methods.
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Expert Judgement in Pharmacoeconomic Studies: Guidance and Future Use
PharmacoEconomics, 2000Co-Authors: Christopher H. Evans, Bruce CrawfordAbstract:Research in the field of pharmacoeconomics has increased substantially during the past decade. Much of this research has been on the design and analysis of data concerning the relative merits of one drug or device compared with another in terms of costs and effects. Concomitant with these evaluations has been the development of guidelines for the conduct of economic evaluations in several countries. However, despite an increase in research, little attention has been paid to how different study designs may influence the results of a study. The use of Expert Judgement in decision analytic modelling is one area where design issues may influence the findings of a study. This issue is examined for the case of modified Delphi and Delphi panels. Although the use of Expert opinion in modelling studies seems to be widespread, there is little consistent application, understanding or reporting of the techniques used. In particular, the definitions of techniques vary between studies, the criteria for determining when consensus is reached vary, and the reporting of these criteria is absent. Future studies using Expert Judgement should be more aware of the controversies surrounding the issue and provide more reporting of the techniques used. It is proposed that future validation exercises may assist researchers in determining the most appropriate application of methods.
Martine J Barons - One of the best experts on this subject based on the ideXlab platform.
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anticipated impacts of brexit scenarios on uk food prices and implications for policies on poverty and health a structured Expert Judgement approach
BMJ Open, 2020Co-Authors: Martine J Barons, Willy P AspinallAbstract:Introduction Food insecurity is associated with increased risk for several health conditions and with poor chronic disease management. Key determinants for household food insecurity are income and food costs. Whereas short-term household incomes are likely to remain static, increased food prices would be a significant driver of food insecurity. Objectives To investigate food price drivers for household food security and its health consequences in the UK under scenarios of Deal and No-deal for Britain’s exit from the European Union. To estimate the 5% and 95% quantiles of the projected price distributions. Design Structured Expert Judgement elicitation, a well-established method for quantifying uncertainty, using Experts. In July 2018, each Expert estimated the median, 5% and 95% quantiles of changes in price for 10 food categories under Brexit Deal and No-deal to June 2020 assuming Brexit had taken place on 29 March 2019. These were aggregated based on the accuracy and informativeness of the Experts on calibration questions. Participants Ten specialists with Expertise in food procurement, retail, agriculture, economics, statistics and household food security. Results When combined in proportions used to calculate Consumer Price Index food basket costs, median food price change for Brexit with a Deal is expected to be +6.1% (90% credible interval −3% to +17%) and with No-deal +22.5% (90% credible interval +1% to +52%). Conclusions The number of households experiencing food insecurity and its severity is likely to increase because of expected sizeable increases in median food prices after Brexit. Higher increases are more likely than lower rises and towards the upper limits, these would entail severe impacts. Research showing a low food budget leads to increasingly poor diet suggests that demand for health services in both the short and longer terms is likely to increase due to the effects of food insecurity on the incidence and management of diet-sensitive conditions.
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anticipated impacts of brexit scenarios on uk food prices and implications for policies on poverty and health a structured Expert Judgement approach
arXiv: General Economics, 2019Co-Authors: Martine J Barons, Willy P AspinallAbstract:Food insecurity is associated with increased risk for several health conditions and with poor chronic disease management. Key determinants for household food insecurity are income and food costs. Whereas short-term household incomes are likely to remain static, increased food prices would be a significant driver of food insecurity. To investigate food price drivers for household food security and its health consequences in the UK under scenarios of Deal and No deal for Brexit . To estimate the 5\% and 95\% quantiles of the projected price distributions. Structured Expert Judgement elicitation, a well-established method for quantifying uncertainty, using Experts. In July 2018, each Expert estimated the median, 5\% and 95\% quantiles of changes in price for ten food categories under Brexit Deal and No-deal to June 2020 assuming Brexit had taken place on 29th March 2019. These were aggregated based on the accuracy and informativeness of the Experts on calibration questions. Ten specialists in food procurement, retail, agriculture, economics, statistics and household food security. Results: when combined in proportions used to calculate Consumer Prices Index food basket costs, median food price change for Brexit with a Deal is expected to be +6.1\% [90\% credible interval:-3\%, +17\%] and with No deal +22.5\% [+1\%, +52\%]. The number of households experiencing food insecurity and its severity are likely to increase because of expected sizeable increases in median food prices after Brexit. Higher increases are more likely than lower rises and towards the upper limits, these would entail severe impacts. Research showing a low food budget leads to increasingly poor diet suggests that demand for health services in both the short and longer term is likely to increase due to the effects of food insecurity on the incidence and management of diet-sensitive conditions.
L.h.j. Goossens - One of the best experts on this subject based on the ideXlab platform.
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experience with Expert Judgement the tu delft Expert judgment data
Wiley Handbook of Science and Technology for Homeland Security, 2008Co-Authors: Roger Cooke, L.h.j. GoossensAbstract:This chapter explores the topic of experience with Expert judgment and the TU delft Expert judgment data
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fifteen years of Expert Judgement at tudelft
Safety Science, 2008Co-Authors: L.h.j. Goossens, Roger Cooke, Andrew Hale, Lj RodicwiersmaAbstract:Over the last fifteen Delft University of Technology (both the Safety Science Group and the Department of Mathematics of TUDelft) has developed methods and tools to support the formal application of Expert Judgement. Over 800 Experts assessed over 4000 variables, in total representing more than 80,000 elicited questions. Applications were made in a variety of sectors, such as nuclear applications, the chemical and gas industries, toxicity of chemicals, external effects (pollution, waste disposal sites, inundation, volcano eruptions), aerospace sector and aviation sector, the occupational sector, the health sector, and the banking sector. The techniques developed at TUDelft can be applied to give either quantitative assessments or just qualitative and comparative assessments. The application of these techniques is driven by a number of principles, including scrutability, fairness, neutrality, and performance control. The overall goal of these formal methods is to achieve rational consensus in the resulting assessments. Performance criteria are based on control assessments, that is, assessments of uncertain quantities, closely resembling the variables of interest, for which true values (e.g., from experiments) are known post hoc. The use of empirical control assessments is a distinctive feature of the Delft methods. A Procedure Guide for Structured Expert Judgement is published by the European Commission as EUR 18820. This paper highlights the comparative assessments for which the Safety Science Group was the prime responsible.
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Expert Judgement elicitation for risk assessments of critical infrastructures
Journal of Risk Research, 2004Co-Authors: Roger Cooke, L.h.j. GoossensAbstract:Governmental bodies and companies are confronted with the problem of achieving rational consensus in the face of substantial uncertainties. The subject area of this special issue (risk and vulnerability assessments and management of critical infrastructures) might be a good example as are risk management of chemical installations and accident consequence management for nuclear power plants. Decisions with regard to infrastructures functioning and possible malfunctioning must be taken on the basis of predictions of technical and organizational system behaviour. These predictions use mathematical models containing scores of uncertain parameters. Decision makers want to take, and want to be perceived to take, these decisions in a rational manner. The question is, how can this be accomplished in the face of large uncertainties? One available source is Experts in the many fields of interest within infrastructures. This paper describes the use of structured Expert Judgement in a formal manner. The paper refers ...
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Expert Judgement elicitation for risk assessments of critical infrastructures
Journal of Risk Research, 2004Co-Authors: R. M. Cooke, L.h.j. GoossensAbstract:Governmental bodies and companies are confronted with the problem of achieving rational consensus in the face of substantial uncertainties. The subject area of this special issue (risk and vulnerability assessments and management of critical infrastructures) might be a good example as are risk management of chemical installations and accident consequence management for nuclear power plants. Decisions with regard to infrastructures functioning and possible malfunctioning must be taken on the basis of predictions of technical and organizational system behaviour. These predictions use mathematical models containing scores of uncertain parameters. Decision makers want to take, and want to be perceived to take, these decisions in a rational manner. The question is, how can this be accomplished in the face of large uncertainties? One available source is Experts in the many fields of interest within infrastructures. This paper describes the use of structured Expert Judgement in a formal manner. The paper refers to the Procedures Guide published by the European Union as EUR 18820. This Procedures Guide addresses two methods for using Expert Judgements developed at Delft University of Technology. The paired comparisons method is particularly suitable to identify the relative importance of attributes in the risk management arena, while the Classical Model, apt to arrive at subjective probability assessments, is particularly suitable to derive uncertainty distributions over model parameters. Examples will be referred to for further illustration of applications relevant in the field of risk assessment and risk management.
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carma food safety and Expert Judgement
2004Co-Authors: H J Van Der Felsklerx, L.h.j. Goossens, A H Havelaar, Maarten Nauta, Roger CookeAbstract:In The Netherlands, Campylobacter infections are estimated to cause yearly many health problems, deaths and considerable economic losses. Effective prevention of human campylobacteriosis requires a well-balanced set of control measures in the chicken meat production chain. To that aim the CARMA project is carried out in The Netherlands. Aspart of the project, RIVM and TU Delft executed an Expert study to obtain estimates on input parameters of the risk assessment model for broiler chicken processing. The Expert study focused on the transmission of Campylobacter in industrial chicken processing plants. Twelve Experts have provided quantile assessments of the query variables. The aggregated Expert data will be used to achieve uncertainty distributions of the model variables. With the results a generic picture will be present which will be used to assess possible risk abatement measures to prevent or reduce Campylobacter contamination in chicken processing lines as much as possible. The goal of this paper is to discuss the results of the Expert Judgement study.
