Analysis of strengths and weaknesses in current research in science education

Research in science education has promise when it is relevant, is adequately conceptualized, and has sound methodology.     

A not so Pacific voyage: the 'floating laboratory' of Nicolas Baudin

Nicolas Baudin's voyage to Australia in 1800 was particularly fractious. Many officers and scientists deserted. When stories of mission mismanagement leaked back to France, Baudin's reputation--and the public reputation of the expedition as a whole--was left in tatters. All was not Baudin's fault, however. Scientific rivalries--disputes over credit and quarrels over mission priorities--undermined his mission from the start, and explain why his attempt to use a 'public' journal to foster teamwork backfired. Unable to control his floating laboratory's paperwork, Baudin became an 'invisible commander'. After the expedition returned, naturalist Fran?ois Péron assumed credit for its work.     

Leading higher education professionals: local,connected, and artful

In this paper, we explore the work life of a scholar new to academia in her methods of leading informally. We discuss five vignettes that offer moments of learning and reflection, including reducing performance anxiety, privileging financial accountability, the rise of the virtual world, the impact of silence, and the potential for confrontation to strengthen working relationships. We offer suggestions as to how contemporary leaders may adapt to the freedom that artful action offers.     

Enhancement and reduction of associative retroactive cue interference by training in multiple contexts

Retroactive cue interference refers to situations in which a target cue X is paired with an outcome in phase 1 and a nontarget cue Z is paired with the same outcome in phase 2, with less subsequent responding to X being seen as a result of the phase 2 training. Two conditioned suppression experiments with rats were conducted to determine whether retroactive cue interference is similarly modulated by a manipulation that influences retroactive outcome interference (e.g., extinction). Both experiments used an ABC renewal-like design in which phase 1 training, phase 2 training, and testing each occurred in different contexts. Experiment 1 found that training the target association in multiple contexts without altering the number of training trials during phase 1 decreased retroactive cue interference (i.e., increased responding consistent with the target association). Experiment 2 found that training the interfering association in multiple contexts without altering the number of interference trials during phase 2 increased retroactive cue interference (i.e., decreased responding consistent with the target association). The possibility of similar mechanisms underlying cue interference and outcome interference is discussed.     

Home start: Third-grade follow-up assessment of a family-centered preschool enrichment program

This study compared third-grade achievement test scores of participants in vertical Home Start (VHS), a preschool individualized program for children from 2 to 5 years of age; with comparable scores of their older and nonprogram siblings. Nonparametric rank ordering assessment revealed significant trends for black VHS children to attain higher rankings on 11 of the 15 subtest measures; no significant ranking differences were obtained with white children. Results indicate that, especially for black children, home-based preschool enrichment may more effectively promote growth in math and basic skills areas related to Cattell's crystallized intelligence, with more limited enrichment effects in such language-linked subject areas as vocabulary and reading.     

The characteristics of iron in high frequency magnetic fields

Not many years ago it was quite generally believed that iron was unable to follow rapid magnetic changes. Experiments which showed an apparent decrease in the permeability of the iron with an increase in the frequency of the magnetic cycle furnished a basis for a theory that iron was magnetically sluggish. Further and more accurate experiments proved, however, that the effects which had previously been ascribed to a peculiarity of the material were in reality caused by eddy currents in the sample. Theoretical calculations were made which demostrated that eddy currents in an iron test piece increased as the square of the frequency and that for even the lower frequencies it was necessary to use quite thin laminations in magnetic circuits in order to eliminate deleterious effects. Furthermore, it was found that due to eddy currents and the magnetic properties of iron, the magnetization in high frequency fields was confined to a thin surface layer of the piece. This “Magnetic Skin Effect” reduced the cross section of the iron which was magnetically active even though the laminations were extremely thin. Careful experimental measurements compared with theoretical calculations proved that the real permeability of iron remained unchanged at frequencies up to about 10⁶ and that previous results had been is serious error due to neglect of the factors mentioned. This fact having been established, efforts were made to see what practical use could be made of iron in high frequency work and to that end some extensive experimental investigations of the saturation curves and core losses were made upon specimens laminated as thinly as was commercially practicable. The resulting data have furnished a basis for design.It is a demostrated fact that the permeability of all metals is unity for the magnetic cycles imposed upon them by heat and light waves. In the region between frequencies of about 10⁶, where the true permeability of iron is practically the same as at zero frequency, and frequencies of about 10¹⁰ where the true permeability of iron approaches unity, the experimental values of μ decrease smoothly with the frequency. What happens to μ in the range of frequencies between the lingest heat waves and the shortest Hertzian waves which have yet been made is a question which has many interesting features but which has not yet yielded to the experimenter.