The effect of US omission in classical aversive and appetitive conditioning of rabbits

Rabbits (Oryctolagus cuniculus) were given either a 100% or a 50% reinforcement schedule in classical conditioning. Two groups received an aversive US (shock) and two groups received an appetitive US (water to the oral cavity). With parameter estimates for the two-phase model serving as the dependent variables, it was possible to define more precisely the effect of US omission with the intermittent reinforcement schedule. For the aversive preparation, the major effect of intermittent reinforcement was to increase the duration of Phase 1, a phase during which response likelihood remains constant at its initial value. Only a small proportion of subjects reflected the effect of US omission during Phase 2, the “learning” phase, this being a low operator limit following trials on which neither the CR nor the US occurred. The major effect of US omission for the appetitive preparation was in Phase 2, primarily a result of a minority of subjects having a low operator limit following trials on which neither the CR nor the US occurred. Many subjects required separate operators for trials on which the CR did or did not occur. The results were interpreted to pose difficulties for strength theories of conditioning, and the limitation implied for successful application of the Rescorla-Wagner theory are discussed. The implications of the data for response-contingent interpretations and for individual differences are also discussed.     

The issue at a glance

The issue at a glance     

Teachers’ technology adoption and practices: lessons learned from the IWB phenomenon

The twenty-first century has seen unprecedented investment from governments around the world in educational technologies in schools. This paper investigates Australian teachers’ adoption and use of a popular technology that has been extensively supported by governments and school systems: the interactive whiteboard (IWB). The study suggests that a number of the barriers identified in the early days of adoption and use of this technology, such as professional support and access, still remain for many teachers, thereby impeding effective practices. The research also found that primary school teachers were using the technology in diverse ways, in contrast to secondary teachers who were using the IWB mainly for instructionist, presentational purposes. We conclude by considering various ways of reducing the effect of the identified barriers to support implementation of educational technologies in the classroom, especially the next generation of technologies promoted by governments and systems.     

A comparison of the dimensions used by Iranian and American students in rating instruction

This study investigated the dimensions of teacher behavior and classroom characteristics used by Iranian high school students (N=880) in evaluating their classroom experience. Secondly, it compared these dimensions to those used by American high school students (N=599). During January, 1978, both groups of students completed the Classroom Behavior Survey (CBS). Principal components analysis with varimax rotation yielded a 12 factor solution for Iranian data and 14 for the American data. Comparison of the factors suggest that the dimensions on which Iranian and American students evaluate their teachers are substantially different, though the dimensions they use to evaluate characteristics of the course and content are similar.

---

Zusammenfassung Diese Studie untersucht die Dimensionen von Lehrerverhalten und Unterrichtsweisen, die iranische Studenten zur Evaluation ihrer Klassenerfahrungen angewandt haben. Ferner vergleicht sie diese Dimensionen mit den von amerikanischen Sekundarschülern benutzten. Beide Schülergruppen beendeten ihre Untersuchungen über Unterrichtsverhalten im Januar 1978. Eine Analyse der Hauptkomponenten, mit Varimax Rotation, ergab eine 12-Faktorenlösung für die iranischen Daten gegenüber 14 Faktoren für die amerikanischen. Ein Vergleich dieser Faktoren deutet darauf hin, daß die Dimensionen, aufgrund derer die iranischen und amerikanischen Schüler ihre Lehrer bewerten, stark voneinander abweichen, während sich die für die Beurteilung der Kurse und Inhalte gebrauchten gleichen.

---

Résumé Cette étude porte sur les cotes du comportement de l'enseignant et des caractéristiques de la classe utilisées par les élèves iraniens de l'enseignement secondaire. (N=880) dans leur évaluation de leur expérience scolaire. Elle compare ensuite ces cotes à celles utilisées par les élèves américains du secondaire. Les deux groupes d'élèves ont terminé leur enquête sur le comportement de la classe (CBS ECC) en janvier 1978. L'analyse des principales composantes avec rotation varimax a donné une solution à 12 facteurs pour les données iraniennes et à 14 facteurs pour les données américaines. La comparaison des facteurs suggère que les cotes selon lesquelles les élèves iraniens et américains évaluent leurs enseignants sont notablement différentes, bien que celles qu'ils utilisent pour évaluer les caractéristiques du cours et de son contenu soient similaires.