The Use of Prolog for Improving the Rigour and Accessibility of Ecological Modelling
We introduce three concepts that offer considerable benefit to the process of ecological modelling: the descriptive representation of models; the explicit representation of knowledge about how to model; and the development of knowledge-based systems that can help ecologists construct models. Prolog, a computer language based on formal logic, has much to offer in realising these ideas. We introduce the concept of a ‘model blueprint’, a complete, formal specification of the structure of a model, and show how a blueprint can be represented as a Prolog program, basing our analysis on system dynamics models for simplicity. We consider ways in which the Prolog interpreter can be used selectively to retrieve information about the model, to check for errors in the formulation of the model, and to evaluate the model mathematically. However, there are drawbacks with this approach, so we discuss ways of overcoming these by implementing - also in Prolog - programs which buffer the user from the difficulties of working at the level of the Prolog interpreter. These include the generation of descriptions of model structure, and the development of a program to help in the construction of simulation models.