Peter Challenor - History Matching - an alternative way of inference for biological systems
Channel: BioInference
Date: 2022-06-28

History Matching - an alternative way of inference for biological systems

Peter Challenor
University of Exeter

BioInference 2022
https://bioinference.github.io/

00:00 Talk
23:46 Q&A

Abstract:
Current models of biological systems are often based on differential equations. Such models offer increased scientific understanding but present challenges for inference. The form of the underlying equations limits our solutions to manifolds in solution space. This is important when we compare the model to data, since ‘all models are wrong’ we can be sure that the real world (and hence the data) does not lie on this manifold. This is known as model discrepancy. Because of this discrepancy conventional inference methods will overfit the data and result in incorrect estimates of uncertainty. Attempts to solve this problem, e.g. by Kennedy and O’Hagan, where inference is carried out both on the model and the discrepancy simultaneously result in serious problems of identifiability. An alternative approach, known as ‘history matching’, approaches inference from a different angle. Rather than try to find the ‘best’ value of the model parameters we find those sets of parameters that cannot have produced the data. Once you have ruled out all the implausible sets of model inputs the ‘best’ ones must be left. In the talk we will set out the issues with conventional inference methods, describe history matching and illustrate the method with biological examples.