A checklist for quality assistance in environmental modelling

The goal of this checklist is to assist in the quality control process for environmental modelling. The point of the checklist is not that a model can be classified as 'good' or 'bad', but that there are 'better' and 'worse' forms of modelling practice. We believe that one should guard against poor practice because it is much more likely to produce poor or inappropriate model results. Further, model results are not 'good' or 'bad' in general (it is impossible to 'validate' a model in practice), but are 'more' or 'less' useful when applied to a particular problem. The checklist is thus intended to help guard against poor practice and to focus modelling on the utility of results for a particular problem. That is, it should provide insurance against pitfalls in process and irrelevance in application. The checklist is designed largely for internal use (within a modelling group) for self-assessment. It can be used as a self-elicitation by competent practitioners, to give form to their own judgements about the models they know intuitively. There are not always single best answers to the questions. What constitutes good practice in one domain may be in conflict with the requirements of good practice in another, and the resolution of such conflicts will often depend on the context. Before commencing the checklist, a few definitions are in order. For the purposes of this checklist we diffentiate between 'users' and 'stakeholders' as follows: A 'user' is someone who exercises the model or who uses its output in some application. A user is necessarily aware of the existence of the model. A stakeholder is one who either participates in the policy process regarding the issue at hand, or who is affected by that process in some way. Stakeholders may or may not be aware of the existence of the model (or of the policy process for that matter)