| Abstract: | This paper is concerned with the growth and development of two fields of study which are customarily separated in both theory and practice. Those who specialize in one area, whether as students, teachers or research workers, are not necessarily familiar with, or required to learn, the state of knowledge in the other, although, as we shall show, there is a considerable commonality of interest. To some extent, this situation is an accident of history and the first part of this paper deals with the events and influences leading to the emergence of each field of study. In the second part, common strands and factors leading to the convergence of the two fields are considered. The third section examines the “state of the art” and evaluates current strengths and weaknesses. Finally, an appraisal is made of the direction of likely future trends. |
