4.1. THE CONCEPT OF A MODEL
Modelling is a method of cognition that consists of creating and researching models. A model is a new object that reflects the essential features of the studied object, phenomenon or process. Thus, the concept of «model» usually includes the general sense of resemblance, similarity to the sample, some type of reflection, i.e. the presence of an external, sensual-looking, palpable and visible similarity of the original with the copy. In addition to the fact of correspondence, the criterion of this correspondence is also important: what exactly in the reflected phenomenon should the model correspond to. Thus, when explaining the idea of modelling, it is necessary to note such important properties of the model as, first, the correspondence of the model properties to the properties of the object and, second, a certain criterion of this correspondence.
When studying different aspects of complex objects, it is necessary to simplify the model, discarding some of its properties. Therefore, the model, in a certain sense, is simpler than the real object, because it does not cover every aspect of the modelled original. This is primarily due to the complexity of the original living systems. Later on, as the knowledge increases, the model can be supplemented with various details, closing nearer and nearer to the real object. Therefore, the creation of the model is cyclical in nature, aimed at a gradual approximation of the model to the original. According to the famous expression of one of the pioneers of cybernetics, W.R. Ashby: «The best cat model is the cat itself.»
However, the model is not only a reflection of our knowledge of the object under study but also a source of new information obtained through the model. Model research allows to assess the behaviour of the simulated object under new conditions or under different influences that are impossible (human studies) or difficult (expensive objects or negative consequences of experiments) to check on the real object. Therefore, in a wider sense, the model can be considered as a mentally represented or materially implemented system, which, by reflecting or imitating the object of study, is able to replace it so that its study gives new information about this object.