Emergence,flexibility, and stabilization of language in a physics classroom

Learning physics is a complex phenomenon. In this article, we use concepts from the theory of nonlinear systems to study the development of language in classroom science in an experimental unit on chaos theory in a German 10th‐grade physics classroom. In ongoing activity, the explanations students developed for phenomena emerged through interactive stabilization and material constraints on the interpretive flexibility of material (artifacts) and discursive representations (talk). Interpretive flexibility both enables novel understandings and differences between private and common public use of these representations. © 2003 Wiley Periodicals, Inc. J Res Sci Teach 40: 869–897, 2003     

Mastery,insight, and the teaching of chemistry

The learning of chemistry is described as a process analogous to the process of making chemical discoveries. Historical examples are given to show how chemists have used their insight to break out of a conceptual loop in order to advance the science. Having the insight to make the intuitive leap necessary to break a conceptual loop is as important as having the mastery of the pertinent facts. As in making chemical discoveries, learning elementary chemistry requires developing insight as well as acquiring mastery of the facts. However, current general chemistry teaching tends to teach facts first and insight later. Suggestions for improving this situation so that insight and facts are learned together are given. Finally, the nature of insight is probed more deeply and presented as a two-step process where the first step is an evaluation of the perceptions about science which are held. Once the student, teacher, or researcher has a clear evaluation of the validity of the perceptions that he or she holds, further significant progress toward understanding or scientific discovery is possible.     

What about classroom Communicators?

Conclusion Note that the comparisons presented in this paper serve only as a springboard in pointing out some of the advantages and limitations of the Classroom Communicator. Like the bicycle and the automobile, each serving a useful purpose under certain conditions, different types of teaching aids and teaching machines will find their use. Not many individuals will want to argue whether the bicycle or the automobile is better. One would hope that an out-of-context decision on the Classroom Communicator versus this or that teaching machine is not made. It is thought, however, that some empirical or logical decision might be made with respect to the use of the Classroom Communicator in the near future. This article is adapted from a paper given by the author as part of a symposium on “Automated Instruction and Programed Learning,” Southeastern Psychological Association, Louisville, Kentucky. The opinions expressed are those of Herbert P. Froehlich, who from 1959 to 1962 was a research officer on the staff of the Chief of Naval Air Technical Training, Memphis, Tennessee, and are not necessarily shared by the Department of the Navy.     

In the bunkers of Binghamton

In addition to being editor ofAcademic Questions and chairman of the National Association of Scholars     

Stability of Individual Differences in Multiwave Panel Studies: Comparison of Simplex Models and One-Factor Models

The purpose of this investigation is to evaluate structural equation models (SEMs) for measures of the same construct collected on multiple occasions (one-variable, multiwave panel studies). Simplex models hypothesize that a measure at any one wave is substantially influenced by the measure at the 0immediately preceding wave; correlations between the same construct measured on different occasions are predicted to decline systematically as the number of intervening occasions increases. Alternatively, a one-factor model posits that a person's score at any one time is a function of some underlying "true" score and a random disturbance that is idiosyncratic to the time; no temporal ordering of correlations is assumed. Both the simplex and one-factor models can befit when there is only a single indicator of each construct at each wave (e.g., scale scores), but there are serious limitations to such models. Stronger models are possible when the same set of multiple indicators (e.g., the items that make up the scale) is measured at each wave. In Study 1, based on students' evaluations of teaching effectiveness collected over an 8-year period, one-factor models fit the data well, whereas simplex models did not. In Study 2, based on personality variables collected over a 4-year period during adolescence, one-factor models again provided an excellent fit to the data, whereas the simplex model did marginally poorer. The results challenge an overreliance on simplex models and demonstrate that a one-factor model is a potentially useful alternative that should be considered in multiwave studies.     

Exploring sex differences in science enrolment intentions: An application of the General Model of Academic Choice

In many countries there remain substantial sex differences in enrolments in elective science courses, despite concerted efforts in recent years to alleviate them. This paper explores the reasons for these differences by comparing models of male and female enrolment intentions in elective courses in biology, chemistry and physics. The models are based on responses from approximately 450 students from 5 Australian high schools. First, a theoretical model, the Science Enrolment Model, was derived from Eccles and colleagues’ General Model of Academic Choice. Students’ responses were then used to develop empirical models of enrolment intentions in the three elective courses. Analyses for the models were conducted using the LISREL “mean structures” extension. Sex differences in the dependent variables in the models were then attributed to the relevant sets of independent variables. Substantial sex differences were identified in measures of perceived career value, interest and performance expectations in all three models which explained between 70% and 82% of the sex differences in enrolment intentions.     

Object recognition through eavesdropping: Passive echolocation in bottlenose dolphins

A bottlenose dolphin (Tursiops truncatus) demonstrated the ability to select the matching object in a matching-to-sample task after listening to another dolphin inspect the sample object via echolocation. The listener was prevented from inspecting the sample himself. In Experiment 1, with objects familiar to both dolphins, the listener’s performance was significantly better than chance. In Experiment 2, objects familiar to only one of the dolphins were used. On these trials, the listener’s performance was significantly better than chance only when the inspecting dolphin made a correct choice. Analysis of the listener’s responses when the inspector made an error demonstrated that this contingency was not due to the listener’s matching the inspector’s response, but was apparently due instead to inadequate information in the echo. The results suggest that the listener was able to “eavesdrop” on echoes produced by the inspector’s clicks and derive characteristics of the sample object.