Interflectance calculations for various luminaires

Previous interflectance tables have dealt principally with three basic types of lighting (Types I, II, and III). The present paper extends the scope of the interflection method by showing how it can be applied to rooms lighted by hanging luminaires. It is found that most cases arising in practice can be covered by six canonic distributions. The effect of mounting height is handled by means of a simple equation.     

Radiant flux through apertures—I

Equations for the calculation of radiant power F through two apertures in series are well known. A characteristic of these formulae is that they give F as a small difference between two large terms. Evidently, the flux through the apertures must decrease as the spacing between them increases; and for large spacing, the inverse-square relation must hold. Instead of exhibiting this behaviour in an obvious manner, however, the traditional equations give the specious impression of an increase in F with increase in spacing. The paper develops an approximate formulae that applies to apertures in the shape of any regular polygon and that shows clearly how the inverse square relation is approached for large separation.     

Radiant Flux Through Apertures— III

This paper completes our treatment of radiant flux through pairs of apertures. In Part II, we obtained approximate equations for rectangular apertures in parallel planes, with the restriction that two apertures be identical and that one be directly above the other. Here we generalize to the case of any apertures that fit into a rectangular grid. The idea for this generalization originated with Ondracek but it is here expressed in matrix notation, which allows coefficients F_ij to be obtained rather simply.     

Book reviews

Post‐Secondary Distance Education in Canada: Policies, Practices, and Priorities. Edited by Robert Sweet. (Edmonton, Alberta: Athabasca University and the Canadian Society for Studies in Education, 1989, 272 pp., $15.95 Canadian.)

The Computer Revolution in Education: New Technologies for Distance Teaching. Edited by Ann Jones, Eileen Scanlon and Tim O'Shea. (New York: St. Martin's Press, 1987. 282 pp. $37.50)     

Producing and practising social justice policy in education: A policy trajectory study from queensland,Australia

Recent philosophical debates have questioned the bases of identity politics in educational research and elsewhere, drawing attention to complexity and diversity of identity. These arguments will be briefly rehearsed, with reference to feminist theory. The criticism that one facet of identity (e.g. gender) cannot be analysed in isolation from others has sometimes been addressed via the study of the 'intersection' or 'interaction' of these various facets. However, others have attacked such approaches, maintaining that such aspects of identity are inseparably intermeshed, and beyond analysis. The poststructuralist account of the self and diversity appears to offer an analytical approach which can address such problems, yet poststructuralist theory also problematises many of the fundamental assumptions underlying emancipatory research in education and elsewhere. This article seeks to debate these various issues, with reference to research in schools. It argues the validity of research concerning specific aspects of identity. Drawing on concepts from feminist theory and reader response criticism, it outlines an approach to such work which rejects the dualisms of relativism/realism, similarity/diversity.     

Exploring the social connections in preschool settings between children labelled with special educational needs and their peers

This paper reports on a small-scale study of the social interactions between six children labelled with special educational needs and their peers in their respective early years settings. Data from play observations, photographs and staff interviews is used to examine the dynamics of the connections that they make with other children. The position of these six children as active agents in making decisions about their peer interactions is highlighted and the ways that this agency is expressed is analysed. By focusing on the personal strategies that the children use to make social connections the findings contribute to the developing understanding of children's relationships within inclusive early years settings. In particular compatible play interests and personalities are identified as significant factors that attract children to one another in this case study. It also emerged that recurrent playmates did not feature consistently in the social exchanges involving this group of children. This factor is considered in the context of it being indicative of the social connections that children labelled with special educational needs pursue. Suggestions for further investigation are proposed and key practice messages offered around developing awareness and facilitation of social connections between children.     

Are You My Grandmother?: Constructing and Maintaining Stepgrandparent Identity and Roles

The disruption of the biological family unit due to divorce or separation followed by remarriage or re-partnering has a profound impact on every family member, including extended family members. An individual becomes a stepgrandparent through later life re-partnering, when an adult child becomes a stepparent, or when a stepchild becomes a parent. In order to gain a greater understanding of the communication influencing the development and maintenance of stepgrandparent roles and identity, a qualitative interpretive analysis method was employed as a guide for interviews with 41 adult stepfamily members across two generations of stepfamily membership: stepparents and stepgrandparents.