Relative preferences for various bivalued ratio schedules

Widely cited experiments on optimal foraging have used bivalued distributions as representing environmental stochasticity, characterizing these in terms of their arithmetic means. In contrast, research on free-operant choice has established that organisms prefer variable patterns of food delivery, relative to fixed patterns with the same mean values. To explore such departures from linear averaging, specifically with respect to bivalued alternatives, pigeons were given choices between a fixed-ratio (FR) schedule of food delivery that required 15, 30, or 60 responses and bivalued variable-ratio schedules with an arithmetic mean of 60,5 or 60, A bivalued schedule of 1 and 120 was preferred almost exclusively over each of the FR values. With a bivalued schedule of 15 and 105, there was a shift of preference, most notably in the FR-15 condition, but in no case was linear averaging a good predictor of the birds’ choices. Geometric averaging fared better, but even this failed to represent the apparent salience of the minimum value of the bivalued schedule in some conditions.     

Students in Australian Catholic and Independent Schools Have More Positive Learning Environments: Evidence From the 2012 PISA Study

Critics of Catholic and independent (nongovernment) schools in Australia contend that the higher levels of performance of students in nongovernment schools can be dismissed as simply a function of student- and especially school-level socioeconomic status (school-SES). A recent article extends this critique to school-sector differences in students’ evaluations of their teachers and schools, arguing that the observable school-sector differences are because of differences in school-SES, not because of school-sector differences in their teachers and schools. In response, this article reviews these arguments and focuses on school-sector differences in students’ evaluations of their teachers and schools using the Organization for Economic Development and Cooperation’s (OECD) measures in the PISA 2009 study. On eight of the 10 attitudinal measures, students attending Catholic and independent schools have more positive evaluations and these school-sector differences survive controls for students’ SES, their overall level of achievement and school-SES, which has no substantive influence. Although the effect sizes are generally small (0.06–0.26) their combined influence means that nongovernment school students enjoy superior learning environments which is likely to contribute to their generally higher levels of academic performance in senior secondary school.     

On optimal location and management of a new industrial plant: Numerical simulation and control

Within the framework of numerical modelling and multi-objective control of partial differential equations, in this work we deal with the problem of determining the optimal location of a new industrial plant. We take into account both economic and ecological objectives, and we look not only for the optimal location of the plant but also for the optimal management of its emissions rate. In order to do this, we introduce a mathematical model (a system of nonlinear parabolic partial differential equations) for the numerical simulation of air pollution. Based on this model, we formulate the problem in the field of multi-objective optimal control from a cooperative viewpoint, recalling the standard concept of Pareto-optimal solution, and pointing out the usefulness of Pareto-optimal frontier in the decision making process. Finally, a numerical algorithm – based on a characteristics/Galerkin discretization of the adjoint model – is proposed, and some numerical results for a hypothetical situation in the region of Galicia (NW Spain) are presented.     

‘Science to the Glory of God’. The Popular Science Magazine Ibérica and its Coverage of Radioactivity, 1914–1936

This paper provides a first approach to the history of Ibérica, one of the most important popular science magazines published in Spain before the Civil War. Founded in 1914 by members of the Society of Jesus based at the Ebro Observatory, Ibérica reached a weekly circulation of about 10,000 in the mid 1920s, and was instrumental in extending science education in Jesuit education facilities and in developing a “reactionary modernist” culture that embraced Catholicism and modernisation. By focusing on its coverage of radioactivity and the radium industry, the article aims to examine the magazine’s popularising style and ideology, and to determine its role in the debates regarding the cultural value of science in the first decades of twentieth century Spain.     

The use of microcomputer technology in a modular approach to reading and reading difficulties

This paper outlines the theoretical framework of a two-year two cohort study of inter-related modules to model reading in 300 grades 4, 5 and 6 readers, and describes the specially designed microcomputer programs written in Turbo Pascal to implement this modular approach. In brief, the modular approach postulates the interrelated phonological, morphological modules in processing words and sentence/paragraph processing. These three modules or components are subserved by 10 measurable tasks all implemented on the microcomputer (IBM-PC compatible) with reaction time measures as indices of the different facets of verbal efficiency. Statistical analyses of the large data sets for Phase 1 show the linear structural equation modelling fits the data reasonably well. In particular, the morphology task consistently explains between 32% to 44% of the variance in reading performance in the three grades. The findings lend themselves to specific approaches to habilitation in the different components or sub-components.This study was supported by a grant (No. 410-86-0048) from the Social Sciences and Humanities Research Council of Canada awarded to Che Kan Leong. Simon Lock and Jacky Lau were responsible for the microcompurter programming. Edward Danskin, Melvin Kelley, Donald Simmons, Louise Sellinger, Kristin Strauss and Tara Wiley carried out the experimentation with individual children in the schools. The cooperation of the principals, the teachers and the subjects was greatly appreciated. Requests for reprints should be addressed to Dr. C. K. Leong, Department for the Education of Exceptional children, University of Saskatchewan, Saskatoon, Canada, S7N OWO.