Teaching physics to prospective elementary teachers: Bridging gaps or widening chasms

The education of prospective Elementary and Early Childhood (E&EC) teachers to teach science has been an on-going challenge for science teacher educators. Accordingly, a course in physical science was planned and implemented especially for prospective E&EC teachers. The purpose of this study was to understand the nature of the enacted curriculum and about the forces which constrained its evolution. Miller, the teacher of the course, had no prior experience in teaching prospective E&EC teachers and many of his experiences as a university level teacher were based on his teaching of physics majors. These experiences shaped his approach to teaching the course as did his years as a basketball coach. Miller was an expert in physics and constructed his role as teaching students significant scientific truths. Miller saw the purpose of the course as being to educate the students in science, not to prepare them to teach science. He was unwilling to address the goals of students that were oriented strongly toward becoming better teachers. The beliefs of the teacher constrained the enacted curriculum to an extent that gaps between the needs of students and the enacted curriculum were wider at the end of the course than they were at the beginning. Armstrong College In my opinion I think I failed completely, but I am quite happy with what I am trying to do. I just don't think I executed it well. So I was pretty unhappy with the whole experience in terms of the results, but I was not unhappy with the experience in terms of whether it was worth doing. I think it is important in science to develop free-thinking and being able to come to conclusions. Science is being able to reflect on the human condition, and being able to think about things you don't know about. (Miller)     

Externalities, technological complementarities and sustained economic growth

Externalities as conventionally defined miss many of the spillovers that are both causes and consequences of the technological changes that underlie economic growth. We introduce a much wider concept called technological complementarities. New general purpose technologies (GPTs) rejuvenate the growth process by creating technological complementarities, which are adequately measured neither by total factor productivity (TFP) nor by externalities. There would be major gains from technological change even if the returns on capital invested in innovation never exceeded the returns on investing in existing technologies so that there were neither externalities nor positive changes in TFP.     

Temporal integration in Pavlovian appetitive conditioning in rats

We used an appetitive sensory preconditioning procedure to investigate temporal integration in rats in two experiments. In Phase 1, rats were presented with simultaneous compound trials on which a 10-sec conditioned stimulus (CS) X was embedded within a 60-sec CS A. In Group Early, CS X occurred during the early portion of CS A, whereas in Group Late, CS X occurred during the latter portion of CS A. In Phase 2, CS X was paired simultaneously with sucrose. On a subsequent test with CS A, the rate of magazine entries peaked during the early portions of the stimulus in Group Early and during the latter portions of the stimulus in Group Late (Experiments 1 and 2). Similar response peaks were not observed on tests with a control stimulus that had been presented in compound with a stimulus that did not signal reward (Experiment 2).     

Supplemental instruction in introductory biology I: enhancing the performance and retention of underrepresented minority students

Supplemental instruction classes have been shown in many studies to enhance performance in the supported courses and even to improve graduation rates. Generally, there has been little evidence of a differential impact on students from different ethnic/racial backgrounds. At San Francisco State University, however, supplemental instruction in the Introductory Biology I class is associated with even more dramatic gains among students from underrepresented minority populations than the gains found among their peers. These gains do not seem to be the product of better students availing themselves of supplemental instruction or other outside factors. The Introductory Biology I class consists of a team-taught lecture component, taught in a large lecture classroom, and a laboratory component where students participate in smaller lab sections. Students are expected to master an understanding of basic concepts, content, and vocabulary in biology as well as gain laboratory investigation skills and experience applying scientific methodology. In this context, supplemental instruction classes are cooperative learning environments where students participate in learning activities that complement the course material, focusing on student misconceptions and difficulties, construction of a scaffolded knowledge base, applications involving problem solving, and articulation of constructs with peers.     

Cultured pearls—commercialised biomineralisation

At the turn of the last century there was an ever increasing world demand for pearls while at the same time their known fishing grounds were becoming exhausted. Some way of artificially increasing their production was obviously desirable, and the problem attracted considerable effort. It was an attempt to exploit a scientifically poorly understood phenomenon, and it is interesting, in retrospect, to relate these attempts to recent concepts of biomineralisation. Pearls are, of course, the layers of aragonitic calcium carbonate secreted by molluscs.