Elements of computer modelling: 12 studies for beginners. Study 2: Main stages of modelling

Abstract

This paper is a continuation of our foundational series on computer modelling [1] and presents the main stages of the modelling process, from initial problem formulation through computational experimentation to model validation. We examine the critical process of model creation, emphasising the necessity of simplifying assumptions and the fundamental contradiction inherent in modelling: the need to simplify whilst retaining essential features. Through practical examples using spreadsheet software, we demonstrate computational experiments with electrical circuits, both direct and alternating current, illustrating how mathematical models can be transformed into computer models for investigation. The paper addresses key technical considerations including the discretisation of continuous processes, computational errors in computer calculations, and basic numerical methods. We provide detailed algorithms for implementing these models in spreadsheet environments, making the concepts accessible to beginners. The validation process for ensuring model adequacy is discussed, along with strategies for testing models against known behaviours. This systematic approach to modelling stages provides learners with a practical framework for developing their own computer models across various domains, reinforcing the pedagogical principles established in the first study of this series.