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Bangladesh has experienced the largest mass poisoning of a population in history owing to contamination of groundwater with naturally occurring inorganic arsenic. Prolonged drinking of such water risks development of diseases and therefore has implications for children's cognitive and psychological development. This study examines the effect of arsenic contamination of tubewells, the primary source of drinking water at home, on the learning outcome of school-going children in rural Bangladesh using recent nationally representative data on secondary school children. We unambiguously find a negative and statistically significant correlation between mathematics scores and arsenic-contaminated drinking tubewells at home, net of the child's socio-economic status, parental background and school specific unobserved correlates of learning. Similar correlations are found for an alternative measure of student achievement and subjective well-being (i.e. self-reported measure of life satisfaction), of the student. We conclude by discussing the policy implication of our findings in the context of the current debate over the adverse effect of arsenic poisoning on children. 相似文献
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Mansoor Niaz 《Instructional Science》2008,36(3):233-249
The objective of this study is to facilitate in-service chemistry teachers’ understanding of nature of science and what ‘ideas-about-science’
can be included in the classroom. The study is based on 17 in-service teachers who had registered for a 11-week course on
‘Epistemology of Science Teaching’ as part of their Master’s degree program. The course is based on 17 readings drawing on
nature of science and its critical evaluation. Course activities included written reports, classroom discussions based on
participants’ presentations and written exams. Based on the results obtained this study has the following educational implications:
(a) Experimental data need to be interpreted carefully due to underdetermination of theories by data; (b) Kuhn’s normal science
manifests itself in the science curriculum through the scientific method and wields considerable influence; (c) Trilemma posed
by Collins (Stud Sci Educ 35:169–173, 2000), viz., creation of new knowledge ⇔ Kuhn’s normal science ⇔ teaching nature of
science, provided a big challenge and was thought provoking; (d) Of the different aspects of nature of science suggested by
experts, these teachers endorsed the following as most important: Creativity, Historical development of scientific knowledge,
Diversity of scientific thinking and Scientific method and critical testing; (e) With respect to the contradiction between
the positions of Lederman et al. (J Res Sci Teach 39:497–521, 2002) and Osborne et al. (J Res Sci Teach 40:692–720, 2003),
few supported the position of latter, viz., inclusion of scientific method in the classroom and a majority supported the former,
viz., scientific method as a myth; and (f) Participants were critical of the present stage of research with respect to the
scientific method and suggested the introduction of history, philosophy and epistemology of science to counteract its influence. 相似文献
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The main objective of this study is a reconstruction of students' and teachers' understanding of structure of the atom based on the following framework: a) history of science can be conceived as that of competing rival research programs; b) some of the greatest scientific research programs progressed on inconsistent foundations; c) in actual scientific practice, counter-examples would be considered as mere anomalies; d) work of Thomson, Rutherford and Bohr led to the postulation of atomic models based on competing frameworks of understanding. This study is based on 171 freshman students enrolled in General Chemistry I and 7 chemistry teachers at the Instituto Universitario de Tecnología, El Tigre, Venezuela. All the students and teachers were asked to respond to a 11 item questionnaire and explain their responses. The questionnaire was administered about a month after the students/teachers had finished the topic of atomic structure. Students' and teachers' responses were classified in the following categories: Positivist/inductivist, Transitional and Lakatosian. Results obtained show that students and teachers: a) have a very similar positivist understanding of the progress of science; b) are inconsistent in their responses by switching from a positivist response on one item to a Lakatosian on an another; c) also showed some consistent response patterns by resisting changes in some of their core beliefs by invoking "auxiliary hypotheses"; and d) consider that observable hard experimental facts give science its objective status, whereas the interpretations being subjective perhaps go beyond the fold of science. 相似文献
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Mansoor Niaz 《Instructional Science》2000,28(5):535-536
Volume Contents
Contents of Volume 28 2000 相似文献6.
Mansoor Niaz 《科学教学研究杂志》1989,26(9):785-793
A large proportion of science major college students are unable to translate even simple sentences into algebraic equations. Given the following sentence: There are six times as many students (S) as professors (P) at this university, most students write the following equation: 6S = P, referred to as the reversal error. In order to overcome the reversal error students need to operate in a hypothetico-deductive manner, i.e., performing a hypothetical operation that makes the group of professors six times larger than it really is (S = 6P). The objective of this study is to investigate the relation between student ability to translate sentences into equations, equations into sentences, and student performance in the following variables: formal operational reasoning, proportional reasoning, and introductory freshmen-level chemistry course. The results obtained show that as the student ability to translate sentences into equations and equations into sentences increases, their mean scores in Chemistry I, formal operational, and proportional reasoning increases. This study has found support for the hypothesis that students who lack formal operational reasoning skills (hypothetico-deductive reasoning) may experience more problems in the translation of algebraic equations. 相似文献
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A Conceptual Change Teaching Strategy to Facilitate High School Students' Understanding of Electrochemistry 总被引：1，自引：0，他引：1
Recent research in chemistry education has shown an increasing interest in the facilitation of conceptual change in student understanding of chemical concepts. Most of the studies have tried to show the difference in student performance on algorithmic and conceptual problems. The objective of this study is to go beyond and design a teaching strategy based on two teaching experiments that could facilitate students' conceptual understanding of electrochemistry. The study is based on two sections (control, n = 29; experimental, n = 28) of 10th grade high school students at a public school in Venezuela. Experimental group participated in two teaching experiments designed to generate situations/experiences in which students are forced to grapple with alternative responses leading to cognitive conflicts/contradictions. Results obtained show that learning electrochemistry involves both algorithmic and conceptual problems. On Posttest 1, 93% of the experimental group students responded correctly, in contrast to 39% of the control group. On Posttest 2, 39% of the experimental group responded correctly, in contrast to 0% of the Control group. The difference in performance on both posttests is statistically significant (p < 0.001). It is concluded that the teaching experiments facilitated students' understanding (progressive transitions) of electrochemistry. 相似文献
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It has been shown previously that manipulation of the M demand (amount of information needed for processing) of chemistry problems affects student performance, which suggests that manipulation of logical structure of chemistry problems could also lead to significant changes in performance. The objective of this study is to investigate the following: Given the opportunity for training, what is the effect of increasing (manipulation) the complexity of logical structure of chemistry problems on student performance, and to what extent can cognitive variables explain changes in performance. Results obtained show that (a) even a small increase in the logical structure of a problem can change the role of cognitive variables (mental capacity and formal reasoning) to the extent that increase in logical complexity outweighs the advantage students may have gained through training on a similar problem; (b) the use of algorithms and training on particular types of chemistry problems could lead to a situation in which formal reasoning is the only cognitive variable that explains variance in performance significantly; and (c) after having solved very similar problems on two different occasions with improving performance, the improvement is not retained if the logical structure of a third problem increases considerably. It is concluded that when dealing with significant changes in logical complexity of chemistry problems, developmental level of students is the most consistent predictor of success. A model for the qualitative analysis of logical complexity of chemistry problems is presented. 相似文献
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The main objective of this study is to construct a Lakatosian teaching strategy that can facilitate conceptual change in students' understanding of chemical equilibrium. The strategy is based on the premise that cognitive conflicts must have been engendered by the students themselves in trying to cope with different problem solving strategies. Results obtained (based on Venezuelan freshman students) show that the performance of the experimental group of students was generally better (especially on the immediate posttests) than that of the control group. It is concluded that a conceptual change teaching strategy must take into consideration the following aspects: a) core beliefs of the students in the topic (cf. 'hard core', Lakatos 1970); b) exploration of the relationship between core beliefs and student alternative conceptions (misconceptions); c) cognitive complexity of the core belief can be broken down into a series of related and probing questions; d) students resist changes in their core beliefs by postulating 'auxiliary hypotheses' in order to resolve their contradictions; e) students' responses based on their alternative conceptions must be considered not as wrong, but rather as models, perhaps in the same sense as used by scientists to break the complexity of a problem; and f) students' misconceptions be considered as alternative conceptions (theories) that compete with the present scientific theories and at times recapitulate theories scientists held in the past. 相似文献
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Mansoor Niaz 《科学教学研究杂志》2000,37(5):480-508
Research in science education has recognized the importance of history and philosophy of science. Given this perspective, it is important to analyze how general chemistry textbooks interpret Millikan's oil drop experiment. This study has the following objectives: (a) elaboration of a history and philosophy of science framework based on a rational reconstruction of experimental observations that led to the Millikan–Ehrenhaft controversy; (b) formulation of six criteria based on the framework, which could be useful in the evaluation of chemistry textbooks; and (c) evaluation of 31 chemistry textbooks based on the criteria. Results obtained showed that most textbooks lacked a history and philosophy of science framework and did not deal adequately with the following aspects. (a) The Millikan–Ehrenhaft controversy can open a new window for students, demonstrating how two well‐trained scientists can interpret the same set of data in two different ways. (b) Millikan's perseverance with his guiding assumption shows how scientists can overcome difficulties with anomalous data. (c) Millikan's methodology illustrates what modern philosophers of science consider important issues of falsification, confirmation, and suspension of disbelief. (d) The experiment is difficult to perform even today, owing to the incidence of a series of variables. (e) Millikan's major contribution consists of discovering the experiment to provide confirmation for the elementary electrical charge. © 2000 John Wiley & Sons, Inc. J Res Sci Teach, 37: 480–508, 2000. 相似文献