Expert knowledge elicitation to complement and enhance data collection and monitoring efforts.

Expert knowledge in the form of numerical estimates and the rationale behind such estimates is often used to complement hard data collection. More often than not, this is done through structured questionnaires, and workbooks rather than structured expert elicitation protocols. 

Expert knowledge elicitation (EKE) protocols follow a series of steps akin to the process of formal data acquisition, while trying to mitigate against cognitive individual and group biases. This enhances the transparency, accuracy, and defensibility of results. Repeated evidence indicates that these judgements should be elicited from multiple experts. However, challenges arise when the desired output is one single answer to a question posed to multiple experts whose answers are bound to differ. The various judgements must be aggregated. This aggregation can be done by the experts themselves, through a process of interaction that is designed to encourage consensus (behavioural aggregation). Alternatively, it may be done externally, by applying an aggregation formula (mathematical aggregation).

In this workshop we shall concentrate on the elicitation and aggregation of expert judgements related to uncertain events and quantities, collected through a structured protocol. 

I will present and explain a combined way of aggregation based on the IDEA protocol for EKE (https://www.sciencedirect.com/science/article/abs/pii/S0169207016300450), as well as the adaptations proposed for application in the field of substance use disorders. At the end of this workshop participants will be familiar with the adapted IDEA protocol. They will benefit from short hands-on interactive exercises, lecture style explanations, a list of relevant literature, and relevant contacts in the field. The take home messages will cover:

1. When is EKE needed
2. What are the scientific principles underpinning EKE 
3. Who needs to be involved in a EKE 
4. How to run a successful EKE 
5. Which tools aid running a EKE
6. Considerations specific to the field of substance use disorders

The workshop is aimed at scientists, technical experts and frontline professionals, academics, policymakers, local decision-makers, trainees in the field and (MSc, PhD) students who are, or will soon be involved in decision problems or risk analysis modelling with scarce resources, and insufficient data