Costas Constantinou

An Investigation of the Potential of Interactive Simulations for Developing System Thinking Skills in Elementary School: A case study with fifth‐graders and sixth‐graders

The purpose of this study was to investigate the impact of a simulation‐based learning environment on elementary school students’ (11–12 years old) development of system thinking skills. The learning environment included interactive simulations using the Stagecast Creator software to simulate the ecosystem of a marsh. Simulations are an important tool in any effort to develop system thinking, because they have the potential to highlight the dynamic nature of systems. Before the implementation of the learning environment (over a period of five 90‐min lessons) two written tests were administered to the students, investigating the development of seven aspects of system thinking. The same tests were administered after the implementation. Specifically, four of the tasks included in each test were associated with skills concerning the structure and the elements of a system and three were associated with the processes and interactions taking place within a system. The findings indicated that elementary school students have the potential to develop system thinking skills. The proposed learning environment provoked considerable improvements in some system thinking skills during a relatively brief learning process. However, the learning environment was not successful in promoting feedback thinking. We interpret these results in view of the difficulties encountered by the students. We also discuss the implications of our findings for the design of learning environments.

Students’ Epistemological Awareness Concerning the Distinction between Science and Technology

We have developed an approach for assessing students’ understanding about the distinction between science and technology. The assessment approach focuses on a specific aspect of this distinction, namely the different goal pursued by each of the two domains. Based on this approach, we collected data from two sources: two written tests administered to 183 elementary, 132 middle school and 78 elementary education students and follow‐up interviews with a sub‐sample of the participants. The findings that have emerged from the data analysis indicate that students of all ages commonly fail to distinguish between the goals pursued by science and technology. They also suggest that students possess a vague notion of the two domains in that they tend to draw on a wide variety of criteria to distinguish between them in a non‐systematic and inconsistent manner. Our data also suggest that age and education level do not seem to have a significant impact on the validity and systematicity of students’ response patterns concerning the distinction between science and technology. The study concludes by reporting the various epistemological difficulties that seem to influence participants’ attempts to differentiate and explore the interconnections between the two fields. Our assessment approach can be used in studies or educational interventions that seek to monitor student understandings about science and technology. The findings can be used to inform possible attempts for designing or modifying activity sequences that address this particular aspect of epistemological awareness.

The Pendulum as Presented in School Science Textbooks of Greece and Cyprus

When we refer to scientific knowledge, we, implicitly or explicitly, refer to its three components, namely its conceptual framework, its methodological principles and its cultural aspects. The pendulum is a topic of science teaching and learning where all three of these aspects can be examined with the aim of gaining a holistic appreciation of the transformation of a natural phenomenon into a phenomenon of the physical sciences and how this can then be recontextualized into a topic of school science learning. The main objective of this study is to examine whether this richness of the pendulum as a topic of teaching is revealed in the school science textbooks in Greece and Cyprus, for both primary and secondary education. We will use an analytical mapping instrument in order to determine, whether the pendulum is introduced at some grade level and, if so, in what context. We will then use an interpretive instrument, which relies on taxonomy of science curricula into traditional, innovative and constructivist programs, in order to attach meaning to the analysis. Finally, we will formulate a series of proposals in relation to the educational value of the simple pendulum at the Greek and Cypriot gymnasium level.

Capacity of the Class of MIMO Channels With Incomplete CDI—Properties of Mutual Information for a Class of Channels

This paper is concerned with multiple-input multiple-output (MIMO) wireless channel capacity, when the probability distribution of the channel matrix p(H) is not completely known to the transmitter and the receiver. The partial knowledge of a true probability distribution of the channel matrix p(H) is modelled by a relative entropy D(middot||middot) such that D(p||pnom) les d, d ges 0, where d is the distance from the so-called nominal channel matrix distribution pnom(H). The capacity of this compound channel is equal to the maximin of the mutual information, where the minimum is with respect to the channel matrix distribution, and the maximum is with respect to the covariance matrix of a transmitted signal. The existence of a minimizing probability distribution is proved, and the explicit formula for the minimizing distribution is derived in terms of the nominal distribution pnom(H) and parameter d. A number of properties of the mutual information, minimized over the set of channel distributions, are derived. Specifically, upper and lower bounds are derived for the minimized mutual information, while its convexity with respect to d is shown. In the case of the Rayleigh fading, an explicit formula for the capacity and the optimal transmit covariance matrix are derived.

Information Capacity of MIMO Channels with Relative Entropy Constraint

This paper addresses the issue of multiple-input multiple-output (MIMO) wireless channel capacity, when the probability distribution of the channel matrix p(H) is not completely known to the transmitter and the receiver. The partial knowledge of a true probability distribution of the channel matrix is modelled by using a relative entropy D(pparq). All possible channel matrix distributions p(H) satisfy D(pparpnom) les d, d ges 0, i.e., they lie within d distance from the so-called nominal channel matrix distribution pnom(H). The information channel capacity is defined as a maximin optimization problem, where the mutual information is a pay-off function. The minimum is with respect to the channel matrix distribution, and the maximum is with respect to the covariance matrix of a transmitted signal. Based on the derived characteristics of the pay-off function, the formula for the channel matrix distribution, which minimizes the mutual information, is derived. In the case of the Rayleigh fading, the formula for the information capacity and the optimal transmit covariance matrix are obtained. In addition, the existence of the saddle point of the maximin optimization problem is established for this particular case

Design, Development and Refinement of a Teaching-Learning Sequence on the Electromagnetic Properties of Materials

We describe a process of designing, developing, and gradually refining a teaching-learning sequence (TLS) on electromagnetic properties of materials (EPM). The design of the teaching-learning sequence draws on principles from the frameworks of inquiry-oriented teaching-learning and learning through technological design. Combining these two frameworks was intended to lead to an instructional context that would likely sustain student interest for the extended time that is necessary to attain conceptual understanding of magnetic interactions and electromagnetic phenomena. Also, it was expected to facilitate the development of students’ epistemological awareness regarding the interconnections and distinction between science and technology. The development process involved a series of six implementation-evaluation-revision cycles (two in upper secondary classes in a school setting, two in a science summer club for highschool students, and two in a science content course for pre-service elementary teachers), with a total of 294 participants. In each implementation, we collected data on students’ learning outcomes through various sources, including open-ended assessment tasks and student-constructed artefacts (e.g., technological products and accompanying posters and written reports). After each implementation, we drew not only on the collected data but also on the feedback provided by the teachers, so as to refine the teaching-learning sequence with the intent to enhance its potential to promote its targeted learning objectives. In this study, we illustrate how the empirical data collected during the implementation of the teaching-learning sequence could serve to guide its refinement. We report on particular instances in which the data on student learning outcomes led us to identify specific limitations of the teaching-learning sequence in terms of its facility to promote certain learning objectives and we elaborate on the revisions we undertook so as to address those limitations.