Model specification searches in structural equation modeling using tabu search

This article introduces an alternative structural equation modeling (SEM) specification search approach that is based on the Tabu search procedure. Using data with known structure, the performance of the Tabu search is illustrated. The results demonstrate the capabilities of the Tabu search procedure for conducting specification searches in SEM.     

Determinants of Journalists' Professional Autonomy: Individual and National Level Factors Matter More Than Organizational Ones

This article seeks to map systematically predictors of journalists' perceived professional autonomy. On the basis of survey responses of 1,800 journalists from 18 countries, the study tests the extent to which journalists with different backgrounds and jobs, who work for different media and organizations, under different kinds of ownerships and pressures, in democratic and nondemocratic regimes, can perform their roles as society's main providers of information. We demonstrate that predictors of professional autonomy are twofold: comprising journalists' perceived influences on news work, and objective limits of autonomy that exist beyond journalists' perceptions. The latter reside on 3 levels: the individual journalist level, the organizational level, and the societal level. Journalists' subjective perceptions of political, organizational, procedural, professional, and reference group influences proved to be strongest predictors of professional autonomy. Of the hypothesized objective determinants of journalists' autonomy, ownership, editorial rank, and professional experience had the highest predictive value.     

Pendulums,Pedagogy, and Matter: Lessons from the Editing of Newton's Principia

Teaching Newtonian physics involves the replacementof students' ideas about physical situations with precise conceptsappropriate for mathematical applications. This paper focuses on theconcepts of `matter' and `mass'. We suggest that students, likesome pre-Newtonian scientists we examine, use these terms in a waythat conflicts with their Newtonian meaning. Specifically, `matter'and `mass' indicate to them the sorts of things that are tangible,bulky, and take up space. In Newtonian mechanics, however, the termsare defined by Newton's Second Law: `mass' is simply a measure ofthe acceleration generated by an impressed force. We examine therelationship between these conceptions as it was discussed by Newtonand his editor, Roger Cotes, when analyzing a series of pendulumexperiments. We suggest that these experiments, as well as moresophisticated computer simulations, can be used in the classroom tosufficiently differentiate the colloquial and precise meaning of theseterms.     

How is the body’s systemic nature manifested amongst high school biology students?

This study follows two groups of students (67 in all) through the 3 years of their high school biology education and examines the development of their systems thinking - specifically their models of the human body as a system. Both groups were composed of biology majors, but the students in one group also participated in a PBLbased extension program called “Medical Systems”. Data was gathered by means of concept maps, which the students completed at four strategic stages of the learning process: beginning of 10th grade, end of 10th grade, end of 11th grade and end of 12th grade. At the end of the 3 year learning process, the students’ showed more complex system models. They included a wider range of concepts in their maps, spanning hierarchy levels ranging from the molecular and cellular to the system level. We also found an increase in references to dynamic interactions, but this did not encourage the students to use cellular level processes when explaining phenomena that occur at the systems level. The impact of the PBL teaching method was strongly evident in the complexity of the Medical Systems program students’ concept maps, which heavily emphasized “hierarchy” and “diseases” as system characteristics.     

Hierarchical task analysis ‐ An approach for diagnosing students’ conceptual difficulties

Pupils’ conceptual difficulties in scientific problem‐solving are examined on the basis of their performance on complex tasks and on the simple tasks of which the complex tasks are composed. A theoretical analysis reveals that identical errors on a complex task are not necessarily due to the same errors on the associated component tasks. This is illustrated by reference to actual research findings. The educational implications of this finding are discussed.     

THE COMPLEXITIES OF TEACHING HISTORICAL CONFLICTUAL NARRATIVES IN INTEGRATED PALESTINIAN-JEWISH SCHOOLS IN ISRAEL

This paper addresses the complexities encountered by teachers and students when dealing with conflictual historical narratives in the context of integrated bilingual schools in Israel. The narratives presented are based on rich ethnographic data gathered from a long-standing research effort in the schools. They offer insights into how those involved in the educational initiative draw selectively from formal and informal sources in order to support their identification and sense of belonging within their particular political, national and religious communities. The vignettes rendered present a complex picture that is not necessarily encouraging in terms of the potential of education to help overcome situations of intractable conflict.     

Helping Students Develop Statistical Reasoning: Implementing a Statistical Reasoning Learning Environment

This article describes a model for an interactive, introductory secondary‐ or tertiary‐level statistics course that is designed to develop students' statistical reasoning. This model is called a ‘Statistical Reasoning Learning Environment’ and is built on the constructivist theory of learning.     

University policies under varying market conditions: The training of electrical engineers

This paper analyzes the problem faced by a university in optimizing the quality and quantity of engineers in the face of fluctuating enrollment. This problem is embedded within an equilibrium model that considers the dynamic rational occupation choice of high school graduates and the effect of the students and the university decision on the current and future demand and supply of engineers. The explicit considerations lead to an estimable model that is capable of providing economic forecasts of the demand and supply of electrical engineers under various economic conditions. The model is estimated using aggregate data from Israel. The estimated parameters are consistent with the economic theory and fit the sample well. In particular, the model is capable of estimating the observed cyclical movements in the number of graduating electrical engineers in Israel. Finally, we provide several predictions on the equilibrium number of electrical engineers towards the end of the century.