Elicitation is increasingly important for quantifying expert knowledge in situations where hard data are sparse. This is often the context in which difficult policy decisions are made. It is generally important to elicit from a group of experts, rather than a single expert, in order to synthesise the range of knowledge and opinions of the expert community. (However, SHELF may be used for a single expert with only trivial modification.)
Despite this growing role for elicitation, there is little in the way of training and support available to those who wish to conduct elicitations. SHELF is a response to this shortage. By reading and carefully following the SHELF documentation, it should be possible for an untrained facilitator to carry out competent elicitation.
Tony O'Hagan has designed an e-learning course to teach people how to make the kind of probabilistic judgements that we ask of experts in a SHELF elicitation workshop. The intention is that experts will prepare themselves by taking this course, so making better use of the experts' time in the workshop itself.
MATCH is an online tool that implements much of the SHELF methodology. It can be used as an alternative to the SHELF software for fitting distributions, and quite nicely allows the user to see how the fitted distribution changes as the elicited judgements (median, quartiles, etc.) change. As a product of the project that developed the e-learning course, a simple user guide for MATCH is now available.
Version 2.0 was released in September 2010 and was a significant upgrade. New procedures and new templates were provided, there was additional advice for facilitators and the software was completely revised.
Version 3.0 was released in October 2016 and was an even more substantial upgrade. Enhancements included new procedures for multivariate elicitation, extended advice documents and PowerPoint slide sets to help guide experts in making their judgements.
Version 4 was released in June 2019. It includes new templates and advice on eliciting knowledge about many uncertain quantities.
Comments are welcomed by Tony O’Hagan (firstname.lastname@example.org) and Jeremy Oakley (email@example.com). We would particularly welcome offers of additional materials or suggested amendments to components of SHELF. We intend SHELF to be a growing and open resource for anyone wishing to conduct effective elicitation.