Personalizing and Contextualizing Multimedia Case Methods in University-based Teacher Education: An Important Modification for Promoting Technological Design in School Science

Results of various studies suggest that multimedia ‘case methods’ (activities associated with case documentaries) have many benefits in university-based teacher education contexts. They can, for example, help to ‘bridge the gap’ between perspectives and practices held by academic teacher educators and those held by student-teachers – who may adhere to perspectives and practices commonly supported in schools. On the other hand, some studies, along with theoretical arguments, suggest that there are limits to the effectiveness of multimedia case methods – because, for example, they can never fully represent realities of teaching and learning in schools. Furthermore, often missing from multimedia case methods is the student-teacher in the role of teacher. To address these concerns, we modified an existing multimedia case method by associating it with a special practice teaching situation in a school context. Qualitative data analyzed using constant comparative methods suggest that student-teachers engaged in this modified multimedia case method developed relatively deep commitments to encouraging students to conduct technology design projects – a non-traditional practice in school science. Factors that appeared to influence development of this motivation included student-teachers’ pre-instructional perspectives about science and the personalization and contextualization inherent to the modified multimedia case method.

How do secondary students approach different types of division with remainder situations? Some evidence from Spain

Division-With-Remainder (DWR) problems are particularly complex, as suggested in many studies. The purpose of this work was to establish whether students’ difficulties in DWR problems came from an inadequate initial representation or from an inadequate final interpretation of the numerical answers, and whether remainders could be grouped into two blocks depending on the kind of answer, either directly matching the terms of the division or not. Forty-five Spanish secondary students, aged 12–13, were requested to solve two Types of Division Situations (i.e., Equal Groups and Comparison), each one involving four Types of Remainder (i.e., Remainder-Not-Divisible, Remainder-Divisible, Remainder-as-the-Result, and Readjusted-Quotient-by-Partial-Increments). Our data showed that: (a) the selection of the correct solution procedure depended on the Type of Division Situations, being easier in Equal Groups than in Comparison problems; (b) correct interpretations were higher than the percentages reported in other researches; and (c) success in problems whose answers were the quotient or the remainder was higher than in Readjusted-Quotient-by-Partial-Increments problems. The results obtained suggest that students’ difficulties originate in the initial representation of the DWR problems and that it would be more adequate to refer to the difficulty of Readjusted-Quotient-by-Partial-Increments problems in particular, rather than to the difficulty of DWR problems in general.     

A Case Study of Relationships between Organizational Culture and Curricular Change in Engineering Education

We examined two curricular change efforts at a small, midwestern engineering and science college in order to explore how organizational culture influences curricular change processes. We found that the failure of one effort (measured by inability to sustain the curriculum over time) and the success of the other (the curriculum continues to be offered by the institution) were directly linked to how well the change strategies aligned with the culture of the institution.     

Adaptive control of bi-directionally coupled Lorenz systems with uncertainties

The bi-directionally coupled Lorenz systems are linked to the modeling of a coupled double loop thermosyphon system where the mass momentum and heat exchange are both considered. As the key parameters of the system, known as Rayleigh numbers, increase, the system of differential equations predicts typical flow dynamics in a thermosyphon from heat conduction to time-dependent chaos. In many applications including the thermosyphon systems, there are uncertainties associated with mathematical models such as unmodeled dynamics and parameter variations. Also, under the high heat environment for a thermosyphon, there exist external disturbances quantitatively linked to the Rayleigh numbers. All these sources constitute uncertainties to the dynamical system. Our objective is to design adaptive controllers to stabilize the chaotic flow in each thermosyphon loop with unknown system parameters and existence of uncertainties. The controllers consist of a proportional controller with an adaptive gain and a wavelet network that reconstructs the unknown functions representing the uncertainties. Explicit stability bounds and adaptive laws for the control parameters are obtained so that the coupled Lorenz systems are globally stabilized.     

Widely linear estimation for multisensor quaternion systems with mixed uncertainties in the observations

The optimal widely linear state estimation problem for quaternion systems with multiple sensors and mixed uncertainties in the observations is solved in a unified framework. For that, we devise a unified model to describe the mixed uncertainties of sensor delays, packet dropouts and uncertain observations by using three Bernoulli distributed quaternion random processes. The proposed model is valid for linear discrete-time quaternion stochastic systems measured by multiple sensors and it allows us to provide filtering, prediction and smoothing algorithms for estimating the quaternion state through a widely linear processing. Simulation results are employed to show the superior performance of such algorithms in comparison to standard widely linear methods when mixed uncertainties are present in the observations.     

Diplomas for learning, not seat time: the impacts of New York Regents examinations

Economic theory predicts that improvements in signaling of achievement generated by external exit examination systems will (1) result in students learning more and this in turn will (2) enable them to get better paying jobs. Since New York State had the only statewide curriculum-based external exit exam system in the nation in the early 1990s, hypothesis 1 predicts that New York students should out perform socio-economically comparable students from other states. Cross section analysis of mean 8th grade NAEP math scores and SAT-I scores found that New York students were indeed about one grade level equivalent ahead of where one would expect given their socio-economic background. A similar analysis of dropout rate data found no differences between New York and other states. Hypothesis 2 was tested in HSB and NLS-88 data. Female students who reported that their high school required they pass a minimum competency exam in order to graduate were paid significantly more after they graduated from high school. Men did not earn more but did get a higher hourly wage.     

Public library facility closure: An investigation of reasons for closure and effects on geographic market areas

Through a nationwide survey of potential public library closures from 1999–2003 (the most recent federal dataset at the time of the study), the researchers assessed the reasons for public library closure, actions taken to alleviate possible loss of library services and resources, and the potential effects on users from the librarians' perspective. Geographic information systems (GIS) was used to analyze the demographics and socioeconomics of the geographic market areas around permanently closed library facilities and compared with national averages from the 2000 U.S. Census. The study found a variety of factors lead to closure; however, a lack of use, a sudden reduction in funding, and the opening of another library facility were the most common closure reasons. The actions taken by the community or library system to alleviate the loss of library services and resources depended on the circumstances of each closure. The geographic market areas around permanently closed facilities tended to include poorer and less educated patrons, and more renters than homeowners when compared to the national average from the 2000 U.S. Census. The study presents a methodology using GIS to describe libraries' geographic market areas and illustrates the need for further exploration into reasons for public library closures and the effects of facility site location, relocation, and permanent closure on potential users.     

All Fall Down!

This article reports on a practical activity which provides a realistic context for collecting and analysing data.