Cases of Science Professors’ Use of Nature of Science

Study provides qualitative analysis of data that answers the following research question: how college science faculty teach science and NOS and incorporate aspects of NOS and the history of science into their undergraduate courses? Study concentrates on four cases and more specifically on three introductory science classes and on four instructors who taught those courses. These instructors were chosen as case studies to explore in greater detail what occurs inside introductory science courses in one particular higher institution in the Northeastern United States. Participants’ teaching styles are presented through a combined and detailed presentation of interview data and classroom observations supported with examples from their classroom activities. Constant comparative approach was used in the process of organizing and analyzing data. Findings revealed that participants preferred to use the traditional teacher-centered lecturing as their teaching style and whose main concern was to cover more content, develop the problem solving skills of their students, and who wanted to teach the fundamental principles of their subjects without paying special importance to the NOS aspects. The study also revealed that other variables of teaching science, such as large class size, lack of management and organizational skills, teaching experience, and instructors’ concerns for students’ abilities and motivation are more important for these scientists then teaching for understanding of NOS.     

Content analysis of selected features of K‐8 environmental education research studies in Turkey, 1997–2007

This study aimed to analyze environmental education research (EER) in Turkey conducted in Grades K‐8 and published over the years 1997–2007. Due to the fact that there had been no systematic reviews of EER in Turkey prior to this time period, it was more appropriate to explore the implications of the results of this review for research policies and practices than for educational policies and practices in Grades K‐8. A substantial search of the international and national literature revealed 53 studies that fit the time frame and study characteristics. Three analyses of these studies were undertaken: (a) features of the research method; (b) socio‐demographic characteristics of the subjects; and (c) components of environmental literacy assessed. Three charts were constructed to support these analyses; e.g., one for each analysis. For analysis (a), quantitative surveys were the most common method. For analysis (b), greater attention was paid to the age, grade level, gender and residence of participating students. For analysis (c), greater attention was paid to knowledge of ecology and natural history, and knowledge of environmental problems and issues, less attention was paid to components of affect, and very little attention was paid to socio‐political‐economic knowledge, cognitive skills and environmentally responsible behavior.     

The Reliability and Validity of the Fitjump Photoelectric Cell System for Determining Vertical Jump Height

ABSTRACT

The aim of this investigation was to assess the reliability and validity of the Fitjump system. Fifty-seven participants (age = 22.62 ± 5.24 years, height = 180.69 ± 12.53 cm, body mass = 75.61 ± 9.56 kg) performed three countermovement jump (CMJ) and squat jump (SJ) with a 1-week interval for test and retest reliability. For validity, the participants performed the same jump protocol on the force platform while being simultaneously measured with the Fitjump system. There was excellent test–retest reliability of the Fitjump system for CMJ and SJ with high intraclass correlation coefficient (ICCs) (0.97 and 0.97, respectively), low coefficient variation (CVs) (2.3% and 2.4%, respectively), and low typical error of estimate [(TEE (%)] (4.0% and 4.4%, respectively). For validity, ICCs were extremely high for CMJ and SJ (0.93 and 0.94, respectively), with low TEE (%) (2.9% and 2.0%, respectively). However, Fitjump overestimated jump height for CMJ and SJ (3.54 and 3.37 cm, respectively; p < 0.001) when compared with the force platform. As a conclusion, the Fitjump system demonstrated excellent test–retest reliability and high relationship with a systematic bias for validity. Therefore, the Fitjump system can be used as a portable tool for monitoring vertical jump changes over time, but it should not be used interchangeably with a force platform.     

Exploring challenges of assessing pre-service science teachers’ pedagogical content knowledge (PCK)

The purpose of this paper is to report on the challenges we faced in designing an instrument aimed at measuring pre-service science teachers’ topic-specific pedagogical content knowledge (PCK). After the instrument was conceptualised and developed, it was administered to 30 pre-service chemistry teachers. The findings suggest that the instrument can be used as a teaching tool to enhance pre-service science teachers’ topic-specific PCK along with some limitations. The discussion focuses on the implications of the aforementioned PCK assessment tool for enhancing pre-service science teachers’ topic-specific PCK and the challenges associated with measuring and enhancing pre-service science teachers’ PCK. Finally, our discussion focuses on the ways in which science-teacher educators can engage in transforming the concept of PCK and its use for research and professional development.     

Understanding The Impact of an Apprenticeship-Based Scientific Research Program on High School Students’ Understanding of Scientific Inquiry

The purpose of this study was to understand the impact of an apprenticeship program on high school students’ understanding of the nature of scientific inquiry. Data related to seventeen students’ understanding of science and scientific inquiry were collected through open-ended questionnaires. Findings suggest that although engagement in authentic scientific research helped the participants to develop competency in experimentation methods it had limited impact on participants’ learning of the implicit aspects of scientific inquiry and NOS. Discussion focuses on the importance of making the implicit assumptions of science explicit to the students in such authentic scientific inquiry settings through structured curriculum.     

An experimental investigation of properties of polyethylene reinforced with Al powders

Mechanical and physical properties, such as tensile strength, elongation at break, modulus of elasticity, Shore D hardness, melt flow rate (MFR), and electrical and thermal conductivities of composites with high density polyethylene matrix reinforced with Al powders were investigated experimentally. Measurements of the mechanical and physical properties were performed up to a reinforcing component concentration of 30% volume Al powder and compared with mathematical models from the literature. The obtained results have shown that experimental data were in good agreement with theoretical data. The ultimate tensile strength (UTS) and elongation at break decreased with increasing Al powder content, which was attributed to the introduction of discontinuities in the polymer structure, and modulus of elasticity increased with increasing Al content. The composite preparation conditions allowed the formation of a random distribution of metallic particles in the polymer matrix volume for system high density polyethylene-Al (HDPE-Al). There was a cluster formation of Al particles at higher Al contents in the polymer matrix. Electrical and thermal conductivity values of HDPE-Al composites were higher than pure HDPE values.     

Cyclic codes over some finite quaternion integer rings

In this paper, cyclic codes are studied over some finite quaternion integer rings with respect to the quaternion Mannheim distance.     

ARGUMENTATION AND STUDENTS’ CONCEPTUAL UNDERSTANDING OF PROPERTIES AND BEHAVIORS OF GASES

The purpose of this study was to explore the impact of argumentation-based pedagogy on college students?? conceptual understanding of properties and behaviors of gases. The sample consists of 108 students (52 in the control group and 56 in the intervention group) drawn from 2 general chemistry college courses taught by the same instructor. Data were collected through pre- and post-tests. The results of the study show that the intervention group students performed significantly better than the control group students on the post-test. The intervention group students also showed significant increase in their test scores between pre- and post-test. While at least 80?% of the students in the intervention group abandoned their initial ideas on all of the 17 alternative conceptions that were identified by the authors but one, the percent of student abandoning their initial ideas in the control group was less than 50. The discussion focuses on the implications of these results for addressing students?? alternative conceptions, promoting the argumentation?Cpedagogy in college science courses and the challenges associated with the use of argumentation in college science classrooms.