Affordance as context

The concept of affordance is relatively easy to define, but has proved to be remarkably difficult to engineer. This paradox has sparked numerous debates as to its true nature. The discussion presented here begins with a review of the use of the term from which emerges evidence for a two-fold classification—simple affordance and complex affordance. Simple affordance corresponds to Gibson's original formulation, while complex affordances embody such things as history and practice. In trying to account for complex affordance, two contrasting, but complementary philosophical treatments are considered. The first of these is Ilyenkov's account of significances which he claims are ‘ideal’ phenomena. Ideal phenomena occupy are objective characteristics of things and are the product of human purposive activity. This makes them objective, but not independent (of any particular mind or perception) hence their similarity to affordances.

The second perspective is Heidegger's phenomenological treatment of ‘familiarity’ and ‘equipment’. As will be seen, Heidegger has argued that familiarity underpins our ability to cope in the world. A world, in turn, which itself comprises the totality of equipment. We cope by making use of equipment. Despite the different philosophical traditions both Ilyenkov and Heidegger have independently concluded that a thing is identified by its use and that use, in turn, is revealed by way of its affordances/significances. Finally, both authors—Heidegger directly and Ilyenkov indirectly—equate context and use, leading to the conclusion that affordance and context are one and the same.     

EPLOT: a machine-independent graphics system

EPLOT was designed as an inexpensive and interactive small graphics library to be run on workstations, stand-alone microcomputers and mainframes, or microcomputers used as graphics terminals. It started as a minor extension to the machine-independent UNIX PLOT library but now includes capabilities for menu and mouse operations, animation, and other functions required in student projects. EPLOT allows the easy development and transfer of interactive graphics programs between SUN, MSDOS, Amiga, ATARI, and Apple Macintosh systems. It has played an important role in the philosophy of the computer graphics course offered at the authors' institution. The scope of EPLOT is demonstrated through a series of projects and programs     

A THEORETICAL AND EXPERIMENTAL INVESTIGATION OF THE CONVECTIVE DRYING OF AUSTRALIAN PINUS RADIATA TIMBER

A series of experiments on the convective drying of Pinus radiata has been undertaken at the CSIRO Division of Forest Products in Australia. This paper uses the experimental results to compare predictions from both a comprehensive mathematical model, which includes wood temperature, moisture content and pressure distributions, and a simplified model (two versions) which assumes constant total pressure. From the- simulations, it is seen that both models adequately predict the overall kinetics of the wood drying process. For a complete understanding of the heat and mass transfer phenomena that occur in wood during drying the comprehensive model is necessary. However, it is computationally long and expensive, and as such, does not suit the practical drying needs of the timber industry in Australia. Consequently, the simplified model, which has acceptable computation time and sufficient accuracy for engineering purposes, enables die wood drying process to be optimised from both performance and economic perspectives.     

Family structure and the mental health of children. Concurrent and longitudinal community-wide studies

This study provides a map of variations of families and some of the core relationships between types of family and the mental health of children. Family types in a poor, black urban community were defined in terms of the adults present at home. The resulting taxonomy is based on two populations: half of the community's 1964 first-grade children and families and the entire 1966 first-grade children and families. Eighty-six family types were found, falling into ten major classes. Family type was found to be strongly related over time to the child's social adaptational status (SAS) and his or her psychological well-being. The results suggest that (1) mother alone families entail the highest risk in terms of social maladaptation and psychological well-being of the child; (2) the presence of certain second adults has important ameliorative functions--mother/grandmother families being nearly as effective as mother/father families, with mother/stepfather families similar to mother alone in regard to risk; and (3) the absence of the father was less important than the aloneness of the mother in relation to risk.