The Quarks of Object-Oriented Development

Even though object-oriented development was introduced in the late 1960s (beginning with the Simula programming language), OO development has not yet lived up to its promises. A major stumbling block to reaping the promised benefits is learning the OO approach. One reason that learning OO is so difficult may be that we do not yet thoroughly understand the fundamental concepts that define the OO approach. When reviewing the body of work on OO development, most authors simply suggest a set of concepts that characterize OO, and move on with their research or discussion. Thus, they are either taking for granted that the concepts are known or implicitly acknowledging that a universal set of concepts does not exist. Several authors, asserting there is no clear definition of the essence of OO, have called for the development of a consensus. While a few have tried to develop such a consensus, to date a thorough review of the literature and identification of the fundamental concepts of the OO approach has been lacking. The goal of this article is twofold: to identify and describe the fundamental concepts, or quarks, of object-oriented development, and identify how these concepts fit together into a coherent scheme.