Abstract
Ph.D.
Until recently the majority of computer aided instruction (CAl) programs available for the teaching of history, only provided elementary facilities such as drill-and-practice exercises. Some of the more advanced systems use simulation techniques to create
fictitious historical situations. These simulation systems take the form of computer games where the participants have to make decisions on historical situations with which they are confronted. The initial aim of this study was to develop a CAl-system for the teaching of history in which historical field battles could be simulated, or more correctly, in which a particular field battle situation could be reconstructed. By using the system, a student could get a better understanding of the different factors which
played a role during a specific battle. It soon became clear though, that the original aims were too broad and too general. The decision was therefore made to undertake a study of the dynamic interrelationships of time and space with reference to field battles. A model was developed which provides a framework for the transformation of often unstructured and diffuse time and space relationships into more specific, structured values which can be loaded into the database of a computer. Historical field battles are used as a vehicle to outline the functioning of the model. After a history teacher or historian has analysed and restructured a specific field battle into relations that can be computerized, a history student can interactively formulate his questions on the time-space relationships of the battle under study. In the field battle model, the concept of an "event" plays an important role. An event defines an action or activity which took
place during a field battle. Two of the major constituents of an event are the time when the event took place, and the geographical position where it occurred. Therefore much of the work reported in this thesis covers the development of algorithms for the representation of time and space relations. Algoritmhs were developed for the interactive drawing of geographical maps of the area where the battle took place. The main building blocks of a geographical map are points, icons, lines and areas. Special attention was given to the representation of these entities. Due to the limited viewing area available on the screen of a micro computer, an area clipping algorithm was
developed for the display of selected parts of the map. Time which is observed under operational conditions during a field battle is referred to as "perceived time". Perceived time is often vague and even unreliable. An algorithm was developed through which these vague time references are transformed to more specific "clock time" values. The algorithm constructs a time network, using the vague known time of occurrence of events, to sequence the events relative to each other. By solving this network, the time of occurrence of the events forming part of the network, are determined to a fair degree of accuracy. These time values and other relevant information are entered into the
database of a micro computer system, to be used for instructional purposes.