This is an interesting book about models and modelling process which naturally splits into two parts. In the first part, the authors discuss the general theory of modelling going step by step from the construction of a model to its testing and validity. The exposition starts with numerous examples that reflect many-sided meanings of the word “model.” In accordance with the definition given by the authors, any product resulting from man’s activity, any work of art, any scientific paper or article in a newspaper are classified as models. Despite their diversity, all models share some common ideas such as the structural aspects of the modelling process. The authors approach the study of models and modelling from the point of view of system theory considering a model as a system reflecting a section of reality which is the system itself and the process of modelling is defined by mappings between these systems. All the considerations are based on systems analysis and systems design as well as on the theory of morphisms, mappings which preserve parts of the underlying structures of the modelled object. The structures of morphisms permit a very detailed characterization of models and help to describe their set-up. The evaluation of a model is regarded as a stochastic process and leads to the determination of its range of validity which depends on the evidence available to the evaluator. The validity of a model comes as a result of its testing in adequate procedures, comparison to existing models, and its acceptance through the consensus among the members of a scientific community. An interesting conclusion made by the authors is that modelling is not only a highly specialized technical process requiring outstanding competence and skills, but also an art demanding creativity and imagination from the person creating the model. The first part consists of 11 chapters: Models, Systems, Mappings, Characterizing models, The art of modelling, Inference, Probabilities, Tolerance, Tests, Validity, and Suggestions for further reading.
In the second part specific examples of models arising in natural sciences suggested and developed by various authors have been collected in order to give more practical ground to the theoretical considerations. The list of eight selected models impresses the reader with its richness introducing a model for the evolution of galaxies, a model for the reconstruction of the genesis of the Earth and the generation of environmental conditions favorable for the development of life, the model for the evolution of the genus Homo, a water balance model identifying human impacts on floods, a model of a glass melter describing the immobilization of nuclear waste by vitrification, a model for the potential underground transport of nuclear wastes and interactions between the hazardous substances and the matrix material, a model for numerical weather prediction, and a model simulating consequences of a severe accident in a nuclear power plant. Careful analysis of these models reveals their common features and helps better understanding of the theoretical material. In a brief introduction to the Appendix, the authors comment on various important aspects of modelling like validity, dependability, possibility for experimental improvement for the models under consideration.
Although the book has an extensive list of references, to facilitate the access to information on various aspects of modelling, the authors provide a brief but useful guidance on the bibliography suggesting sources for additional references in Chapter 11.
There are three fundamental skills required for a successful modelling: intuition, solid theoretical background, and experience. The book under review obviously cannot develop the reader’s intuition, but it does help to achieve progress with the remaining two factors through a thorough study of the theoretical background in the first part and the variety of models in the second part. It shall prove to be useful both for theoretists interested in the foundations of modelling and specialists interested in applied modelling.