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1.
C. Medina 《Science & Education》2004,13(7-8):631-640
This paper conveys information about a Physicslaboratory experiment for students with some theoretical knowledge about oscillatory motion. Students construct a simple pendulum that behaves as an ideal one, and analyze model assumption incidence on its period. The following aspects are quantitatively analyzed: vanishing friction, small amplitude, not extensible string, point mass of the body, and vanishing mass of the string. It is concluded that model assumptions are easilyaccomplished in practice, within small experimental errors. Furthermore, this way of carrying out the usual pendulum experiments promotes a better understanding of the scientific modeling process. It allows a deeper comprehension of those physical concepts associated with model assumptions (small amplitude, point mass, etc.), whose physical and epistemological meanings appear clearly related to the model context. Students are introduced to a scientific way of controlling the validity of theoretical development, and they learn to value the power and applicability of scientific modeling. 相似文献
2.
Akihiko Saeki Akiko Ujiie Masami Tsukihashi 《Community College Journal of Research & Practice》2013,37(5-6):417-424
Since April, 1996, Kanazawa Technical College has offered a cross-curricular course for first-year and second-year students using a TI-83 (Graphing Calculator) and a Computer Based Laboratory (CBL). The goal of the course is for students to learn about the connection between mathematics and physics through hands-on activities. Students conduct experiments on the motion of a person walking, the dropping of an object, the cooling rate of water, the motion of a swinging pendulum, and sound waves. This is the first time that the TI-83 calculator and the CBL have been used in Japan to explore physical phenomena in a classroom situation based on the Japanese curriculum for mathematics and physics. The following findings were obtained: Most students (a) replaced their naive assumptions regarding the laws of physics with scientific concepts; (b) independently made connections between the results of experiments and their previous mathematical knowledge; (c) reported that their level of interest in physical phenomena and science had either not decreased or had improved, (d) valued mathematics more, and (e) realized the importance of cooperative work. The use of CBLs and TI-83s changed not only the authors teaching style but also students attitudes. Students had ownership of their experiments, and they engaged in higher-order thinking skills such as making predictions, analyzing data, and modeling data with equations. As a result, students became more interested in learning mathematics and science. 相似文献
3.
Dewi Heijnes Wouter van Joolingen Frank Leenaars 《Journal of Science Education and Technology》2018,27(1):45-56
We investigate the way students’ reasoning about evolution can be supported by drawing-based modeling. We modified the drawing-based modeling tool SimSketch to allow for modeling evolutionary processes. In three iterations of development and testing, students in lower secondary education worked on creating an evolutionary model. After each iteration, the user interface and instructions were adjusted based on students’ remarks and the teacher’s observations. Students’ conversations were analyzed on reasoning complexity as a measurement of efficacy of the modeling tool and the instructions. These findings were also used to compose a set of recommendations for teachers and curriculum designers for using and constructing models in the classroom. Our findings suggest that to stimulate scientific reasoning in students working with a drawing-based modeling, tool instruction about the tool and the domain should be integrated. In creating models, a sufficient level of scaffolding is necessary. Without appropriate scaffolds, students are not able to create the model. With scaffolding that is too high, students may show reasoning that incorrectly assigns external causes to behavior in the model. 相似文献
4.
This paper describes life-span development ofunderstanding about pendulum motion and effectsof school science. The subjects were 2,766 peopleranging from kindergartners up to 88 years seniorcitizens. The conflict and consensus between childrenand their parent's understanding of pendulum motionwere also analyzed. The kindergartner's understanding,mostly non-scientific, made a marked developmental changeto another type of non-scientific understanding by thetime they reach G 4. Parents with scientific understandingdo not presumably nurture scientifically minded children,even though about half of them can apply scientificconceptions that shorter pendulums swing faster, andthe amplitude and speed of pendulum motion do not dependon its weight. There seems to be another type ofdevelopmental change from scientific understanding tonon-scientific understanding around their fifties. Itis suggested that the scientific understanding in thepublic about pendulum motion become predominant due tothe educational intervention through school science. 相似文献
5.
论述了一种抑制载重绳索参数激励横向振动的简便方法. 假设绳索底端的质量受到一个垂直简谐激励并忽略载重绳索高阶振型的影响, 载重绳索的运动方程可以用一个带有立方非线性项的Mathieu方程来描述. 根据Mathieu方程的有关理论, 在载重绳索系统中, 当索端质量垂直振动的频率接近绳索横向振动固有频率2倍时, 一旦索端质量垂直振动的幅度超过某个临界数值时, 绳索将产生参数共振. 为了避免这种现象, 建议在索端质量上加装一个减振器以削减索端质量的垂直振动, 进而抑制绳索的横向振动. 实验验证了该减振方案的有效性. 相似文献
6.
Danilo R. Diedrichs 《PRIMUS》2019,29(7):712-723
Abstract: Harvesting models based on ordinary differential equations are commonly used in the fishery industry and wildlife management to model the evolution of a population depleted by harvest mortality. We present a project consisting of a series of scenarios based on fishery harvesting models to teach the application of theoretical concepts learned in a differential equations course to scenarios encountered in real fisheries. These projects require a thorough understanding of simplifying assumptions inherent in various models, as well as a qualitative analysis of phase portraits, bifurcations, and stability of steady states. Parameters are estimated and equations are sometimes solved both analytically and numerically. Students learn to respond to a professional request from a fishery in the form of a scientific report, which requires organizing and communicating assumptions, models, solution methods, results, and a final recommendation with clarity and professionalism. 相似文献
7.
采用计算机模拟的自我指导实验探究任务,以小学高年级和初中学生为被试,分析其探究中使用的实验设计策略和证据评价策略,并探讨中小学生科学探究策略的发展特点。研究发现:科学探究中学生所使用的实验设计策略按发展水平由高到低分别有完全设计策略、局部连锁策略、局部控制策略、分离变量水平策略和无策略五种;所使用的证据评价策略主要有:两两比较策略、共同发生策略、直觉评价策略和无策略四种。在简单的任务中被试虽然也使用了正确的策略,但这些策略的掌握往往是自发形成的,探索的方法和策略的掌握仍然需要有意识的培养。 相似文献
8.
Michael R. Matthews 《Science & Education》2004,13(7-8):689-715
Galileo’s discovery of the properties of pendulum motion depended on his adoption of the novel methodology of idealisation. Galileo’s laws of pendulum motion could not be accepted until the empiricist methodological constraints placed on science by Aristotle, and by common sense, were overturned. As long as scientific claims were judged by how the world was immediately seen to behave, and as long as mathematics and physics were kept separate, then Galileo’s pendulum claims could not be substantiated; the evidence was against them. Proof of the laws required not just a new science, but a new way of doing science, a new way of handling evidence, a new methodology of science. This was Galileo’s method of idealisatioin. It was the foundation of the Galilean–Newtonian Paradigm which characterised the Scientific Revolution of the 17th century, and the subsequent centuries of modern science. As the pendulum was central to Galileo’s and Newton’s physics, appreciating the role of idealisation in their work is an instructive way to learn about the nature of science. 相似文献
9.
When identifyinginstruments that have had great influence on the history of physics, none comes to mind more quickly than the pendulum. Though first treated scientifically by Galileo in the 16th century, and in some respects nearly `dead' by the middle of the 20th century; the pendulum experienced `rebirth' by becoming an archetype of chaos. With the resulting acclaim for its surprising behavior at large amplitudes, one might expect that there would already be widespread interest in another of its significant nonlinearities. Such is not the case, however, and the complex motions of small amplitude physical pendula are barely known. The present paper shows that a simply-constructed metallic rod pendulum is capable of demonstrating rich physics in a largely unstudied area. 相似文献
10.
用单摆法测量重力加速度是普通物理实验中常用的方法,但在实验中,摆角、摆长和周期数常常对重力加速度的测量误差产生一定的影响.文章主要分析不同摆角、摆长及周期数三个条件对测重力加速度的影响,最终由处理分析结果可知,在普通物理实验室里,取摆角、摆长=47或55cm、周期数次,处理得到的重力加速度与本地的理论计算值很接近. 相似文献
11.
We show that the treatment of pendulum movement, other than the linear approximation,may be an instructive experimentally based introduction to the physics of non-lineareffects. Firstly the natural frequency of a gravitational pendulum is measured as functionof its amplitude. Secondly forced oscillations of a gravitational pendulum are investigatedexperimentally without limiting amplitudes. By this arrangement new phenomena, thebistability and the jump-effect, can be observed. In the case of bistability the drivengravitational pendulum can oscillate in two different stable modes. Either it oscillateswith a small amplitude and approximately in phase with the exciting torque or it oscillateswith a larger amplitude and approximately anti-phase. The jump effect is the spontaneoustransition from one mode of oscillation to the other. Both effects can be demonstrated andexplained. 相似文献
12.
We show that the treatment of pendulum movement, other than the linear approximation,may be an instructive experimentally based introduction to the physics of non-lineareffects. Firstly the natural frequency of a gravitational pendulum is measured as functionof its amplitude. Secondly forced oscillations of a gravitational pendulum are investigatedexperimentally without limiting amplitudes. By this arrangement new phenomena, thebistability and the jump-effect, can be observed. In the case of bistability the drivengravitational pendulum can oscillate in two different stable modes. Either it oscillateswith a small amplitude and approximately in phase with the exciting torque or it oscillateswith a larger amplitude and approximately anti-phase. The jump effect is the spontaneoustransition from one mode of oscillation to the other. Both effects can be demonstrated andexplained. 相似文献
13.
Ibrahim A. Halloun 《Science & Education》2007,16(7-8):653-697
Following two decades of corroboration, modeling theory is presented as a pedagogical theory that promotes mediated experiential
learning of model-laden theory and inquiry in science education. Students develop experiential knowledge about physical realities
through interplay between their own ideas about the physical world and particular patterns in this world. Under teacher mediation,
they represent each pattern with a particular model that they develop through a five-phase learning cycle, following particular
modeling schemata of well-defined dimensions and rules of engagement. Significantly greater student achievement has been increasingly
demonstrated under mediated modeling than under conventional instruction of lecture and demonstration, especially in secondary
school and university physics courses. The improved achievement is reflected in more meaningful understanding of course materials,
better learning styles, higher success rates, lower attrition rates and narrower gaps between students of different backgrounds. 相似文献
14.
Lucia Mason Pietro Boscolo Maria Caterina Tornatora Lucia Ronconi 《Instructional Science》2013,41(1):49-79
This study examines the contribution of learner cognitive and motivational characteristics to achievement in science at three grade levels. Specifically, the relations between domain-specific epistemic beliefs about the development and justification of scientific knowledge, achievement goals, knowledge, self-concept, self-efficacy, and achievement in science were simultaneously examined. Students in fifth (n = 213), eighth (n = 202), and eleventh (n = 281) grades completed questionnaires measuring the various constructs, and a domain knowledge test. Their grades in science were also collected. Results from structural equation modeling reveal that the hypothesized model fitted the observed data at the three grade levels, although not all expected paths were statistically significant. Students’ epistemic beliefs about the development of scientific knowledge had a direct effect on domain knowledge, whereas beliefs about the justification of scientific knowledge had a direct and an indirect effect via achievement goals on knowledge acquisition. Mastery, performance-approach, and performance-avoidance goals had a direct effect on self-efficacy. Knowledge had a direct and an indirect effect via self-concept on achievement. Educational implications are discussed. 相似文献
15.
杨毅 《衡阳师范学院学报》2004,25(6):106-109
给出灰色点关联度、斜率关联度模型的建模原理和机制，并予以证明。同时，用实例对灰色点、斜关联度两模型进行比较，结果表明，灰色斜率关联度模型优于点关联度模型．其关联序更贴近体育客观实际，为体育科研实际应用提供了理论上的参考依据。 相似文献
16.
圆锥摆模型 总被引：1，自引：0，他引：1
何熙起 《内江师范学院学报》2004,19(4):96-98
由圆锥摆模型,引入同频率、同振幅、振动方向互相垂直的简谐振动的合成和简谐振动的旋转矢量表示法,化抽象的理论为形象的内容,这是学生易于接受、符合教学规律的教学方法。 相似文献
17.
A guide for the perplexed: Scientific educational research, methodolatry, and the gold versus platinum standards 总被引：1，自引：0，他引：1
The paper opens by characterizing recent discourse about empirical educational research as the “new Babel”-critics, using different theoretical vocabularies and making different deep assumptions about the nature of social life, are failing to communicate with each other. After locating some of the critical positions on a left-right continuum, the main discussion focusses upon the end of this continuum where there are located the recent attempts to restore rigor to educational research by using the so-called “gold standard” of randomized field trials. It is argued that positions at this end of the continuum misrepresent the nature of science, and some examples are briefly mentioned in order to covey the point that it is fruitful to view scientists as making convincing cases, cases that appeal to a wide variety of evidence. This assessment of scientific cases is called the “platinum standard”. 相似文献
18.
This study investigates the modelling conceptualisation of secondary school students in two situations related to particle dynamics: pendulum’s motion and horizontal motion. We performed in-depth clinical interviews with secondary school students (N?=?10). Participants’ ideas about properties which are not ‘given’ in empirical observations were explored in order to investigate signs of abstractions and idealisations in their reasoning processes. We proposed contributions to modelling in science education based on Mario Bunge’s epistemology and we employed his basic concepts as the axis to analyse our results: (1) abstractions and idealisations, considered as thought processes required to build conceptual counterparts of concrete objects; (2) theoretical models, meaning hypothetico-deductive systems concerning those conceptual objects; and (3) general theoretical frameworks that allow us to derive those theoretical models. We developed our analysis viewing the ideas presented by participants as concepts-in-action and theorems-in-action as regarded by Gérard Vergnaud’s Theory of Conceptual Fields. Results indicated a gradation in the concepts-in-action mobilised in terms of levels of idealisation and showed that participants do not spontaneously recognise the use of a general theory as a possible way to obtain a theoretical model. These results suggest that science education practices must pay better attention to make abstractions and idealisations explicit in scientific concepts formation, as well as to the heuristic role of theories in model construction. 相似文献
19.
何松林 《实验室研究与探索》2011,30(6)
由摆球浸入不同温度纯水中的小角阻尼振动实验,发现角振幅衰减及振动周期不随液体黏度发生改变。采用改进平均法求解平方阻尼作用下单摆小角振动微分方程,得到角位移随时间变化的解析表达式,据此得到的角振幅衰减及振动周期的定量结果与实验数据符合。得出结论:摆球在液体中振动时受到的流体阻力是与液体黏度无关的平方阻力;平方阻尼常量与液体的密度成正比,与摆球半径及密度的乘积成反比;摆球浸入液体时的阻尼振动、角振幅衰减是非指数型的,衰减速度和振动周期都与平方阻尼常量密切相关。 相似文献
20.
The aim of the study was to investigate students’ views of model evaluation through the lens of personal epistemology. We developed an integrated analytical framework by combining a developmental framework, including absolutist, multiplist, and evaluatist, with a multi-dimensional framework, including limits of knowing, certainty of knowing, and criteria of knowing. Furthermore, we examined the potential influence of the question contexts and the students’ grade levels. A total of 188 secondary school students were surveyed. Students answered two sets of model evaluation questions based on two scientific contexts. After reading the information about the two models, the students had to choose from three epistemic assumptions and then provide written justifications explaining their choice of assumptions. Quantitative and qualitative analyses were conducted for the multiple-choice questions and the written responses. In both contexts there were higher percentages of 11th-grade students choosing the evaluatist assumptions than the eighth-grade students. For students choosing multiplist and evaluatist assumptions, the 11th-grade students were more likely than the eighth-grade students to think in terms of pragmatic and evidential criteria as the criteria of knowing. Different contexts of the questions evoked different views of model evaluation particularly regarding the limits of knowing. Four additional categories of epistemic levels also emerged from the data. This study provides a new framework for understanding students’ thinking about model evaluation. Implications and suggestions for future research are provided.
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