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1.
This study investigated the quality and extent of understanding of certain well-known theoretical concepts which prospective teachers of chemistry in Yemen possess. In addition to the concepts of the conservation of atoms and mass, and the mole, the concepts of atomic mass and balancing chemical equations were chosen for this study. An instrument was built first, then administered to 173 junior and senior prospective chemistry teachers. The results showed that the prospective teachers' understandings of most of the concepts ranged from a partial understanding with specific misconception to no understanding. Only on balancing chemical equations did the prospective teachers show good understanding. The results showed that most prospective teachers depended on mere memorization of the concepts without meaningful understanding. It also found that the prospective teachers' knowledge about the concepts was fragmented and not correlated. The study attributed the prospective teachers' misconceptions to defective instruction. Finally, the study concluded that more effective teaching methods are needed to ensure a sound understanding of these concepts. © 1997 John Wiley & Sons, Inc. J Res Sci Teach 34: 181–197, 1997.  相似文献   

2.
The research reported in this study was designed to answer three questions: (a) What misconceptions do eighth grade students have concerning the chemistry concepts from their textbooks. (b) How is reasoning ability related to misconceptions concerning chemistry concepts. (c) How effective are textbooks in teaching an understanding of chemistry concepts? Five chemistry concepts were used in the study: chemical change, dissolution, conservation of atoms, periodicity, and phase change. Problems concerning the five concepts were given to 247 eighth-grade students in order to assess the students' degree of understanding of chemistry concepts and to identify specific misconceptions. Two pencil-and-paper Piaget-type tasks were used to assess intellectual level. A comparison of intellectual level and scores on the chemistry concepts showed moderate correlations. However, the small number of formal operational students in the sample makes these results inconclusive. A study of the level of understanding of the five chemistry concepts and the nature of the misconceptions held by students indicate a general failure of textbooks to teach a reasonable understanding of chemistry concepts.  相似文献   

3.
The basic concepts of chemistry are an important element of the basic knowledge of high school chemistry. In order to achieve the teaching objectives of high school chemistry, i.e., to cultivate students' "one viewpoint, two bases and two abilities," teaching basic concepts of chemistry should receive attention from low grades on.  相似文献   

4.
This study explores the relationship between affective and cognitive variables in grade 9 chemistry students (n = 73). In particular, it explores how students' situational interest, their attitudes toward chemistry, and their chemistry‐specific self‐concept influence their understanding of chemistry concepts over the course of a school year. All affective variables were assessed at two time points: at the middle of the first semester of grade 9, and at the end of the second semester of grade 9, and then related to students' postinstructional understanding of chemical concepts. Results reveal that none of the affective variables measured at the earliest time point have a significant direct effect on postinstructional conceptual understanding. Looking at the different affective variables as intermediary constructs, however, reveals a pattern in which self‐concept and situational interest measured at the middle of grade 9 contribute to self‐concept measured at the end of grade 9, which in turn, has a positive, significant effect on students' postinstructional conceptual understanding. These results reveal the importance of a strong and positive self‐concept, the feeling of doing well in the chemistry class, for developing a meaningful understanding of scientific concepts. © 2006 Wiley Periodicals, Inc. J Res Sci Teach 44: 908–937, 2007  相似文献   

5.
The Periodic Table of Elements (PTE) is one of the organizing principles in chemistry. Originally it was a list of elements (as substances). Later, the PTE developed into a list of atoms of the elements. However, isotopes and allotropes are difficult to integrate into the PTE. Therefore, difficulties in understanding these terms can be expected. The investigation set off to study secondary school students' concepts of isotopes and allotropes and how the concepts are linked to the PTE. Three specific research questions were addressed: (a) How do secondary school students describe the relationship between fundamental particles constituting an atom? (b) How do they conceive isotopes? and (c) What are students' concepts of graphite and diamond? Multiple choice items were given to 3074 senior high school students. In addition, six interviews were conducted with senior high school students. The data analysis revealed students' alternative concepts, which distinguished between standard atoms and atoms of isotopes. Standard atoms contain neutrons and protons in equal numbers and are more stable. The atomic masses are expressed as integers. Moreover, students considered graphite and diamond as isotopes. The analysis of the results shows that students actively tried to make sense of what they had experienced. © 2003 Wiley Periodicals, Inc. J Res Sci Teach 40: 257–277, 2003  相似文献   

6.
The purpose of this study was to investigate Grade 12 students' understandings of the nature of chemical bonds and energetics elicited across five familiar chemical reactions following a course of instruction. Based on a chemist's analysis of the conceptual area, a list of relevant concepts involved was identified, and the range of five reactions was chosen. These then served as the framework for drawing up a semistructured interview protocol, which was administered to 48 students. The students' responses revealed a range of conceptions at variance with the chemist's view, some of which have not yet been reported in the literature. The implications of the research are that grasping chemistry concepts and principles from the students' perspective is full of pitfalls. There are numerous ways in which students can misconstruct concepts and principles. Teachers, curriculum developers, and textbook writers must be aware of the various ways in which material presented could be misconstrued and hence be a hindrance to student learning. © 1998 John Wiley & Sons, Inc. J Res Sci Teach 35: 569–581, 1998.  相似文献   

7.
This study examined the pedagogical content knowledge of experienced and novice chemical demonstrators. It specifically delineates the nature of the declarative knowledge associated with science teachers' pedagogical content knowledge. Science teachers who (1) teach abstract concepts in chemistry, (2) have a strong interest in using demonstrations as a science teaching strategy, and (3) have high and low levels of experience conducting chemical demonstrations participated in the study. Clinical interviews were used to probe teachers' pedagogical content knowledge. The findings suggest that the experienced chemical demonstrators possess a greater representational and adaptational repertoire for teaching fundamental concepts in chemistry than novices. They also appeared to be more cognizant of the complexity of chemical demonstrations, how these complexities may interfere with learning, and how simplified variations of chemical demonstrations can promote concept learning. The implications for teacher education programs are discussed.  相似文献   

8.

This paper uses a new set of 14 open-ended problems, designed for 14-17-year-old pupils studying chemistry, to attempt to gain some initial insights into the ways pupils solve open-ended chemistry problems. The emphasis is on how concepts and linkages between concepts influence success in solving such open-ended problems. Pupils worked in groups of three attempting to solve the problems and were encouraged to talk freely, to make notes of their progress, and to note their agreed answers. Evaluation sheets were also completed individually by the pupils after each problem. By studying the interactions between pupils by means of written materials, observation and audiotapes, it was possible to build up a picture of the way the pupils approached the problems and to explore some of the reasons for difficulties they experienced. In the light of the evidence, it is suggested that creating the links between 'islands' of knowledge is an important skill in solving open-ended problems and that this skill is not easily achieved by pupils at these ages. The notion that problem solving is a generic skill which can be taught is questioned.  相似文献   

9.
The problem addressed by this study is that first-year college chemistry students learn little of the conceptual material associated with chemistry experiments they perform. The thesis of this research is that the construction of prelab and postlab concept maps help students understand the concepts involved in the experiments they perform. The study was conducted using 32 non–science majors enrolled in a first-year chemistry course. The experimental group constructed prelab and postlab concept maps, while the control group wrote essays explaining the conceptual chemistry of the four experiments used in this study. Both groups took 25-item achievement tests 1 week after each experiment. Prelab and postlab concept maps were scored and evaluated for significant differences. Five students were interviewed to investigate their perceptions regarding the usefulness of concept maps in chemistry laboratories. No significant differences were found between treatment groups with respect to students' conceptual understanding as determined by the multiple choice achievement tests. Students responded very positively toward the use of concepts maps in the laboratory. They felt strongly that constructing prelab and postlab concept maps helped them understand the conceptual chemistry of the experiments. © 1998 John Wiley & Sons, Inc. J Res Sci Teach 35: 1015–1029, 1998  相似文献   

10.
Modern chemistry concepts have the particulate nature of matter at their core. Chemists explain most phenomena in terms of atomic and molecular models. The lack of understanding of chemistry concepts may be linked to the students' inability to build complete mental models that visualize particulate behavior. With computer animation technology, dynamic and three-dimensional presentations are possible. This study explores the effect of computer animations depicting the particulate nature of matter on college students' mental models of the chemical phenomena. A Particulate Nature of Matter Evaluation Test (PNMET) instrument was used to determine the nature of the students' visualizations and, therefore, their comprehension of the chemical concept studied. Animations were used in two treatment situations: (a) as a supplement in large-group lectures, and (b) as both the lecture supplement and an assigned individual activity in a computer laboratory. These two experimental treatments were compared to a control group. Both treatment groups received significantly higher conceptual understanding scores on the PNMET than did the control group. This increased understanding may be due to the superiority of the formation of more expertlike, dynamic mental models of particle behavior in these chemical processes.  相似文献   

11.
ABSTRACT

Context-based learning (CBL), promoting students' scientific text comprehension, and fostering metacognitive skills, plays an important role in science education. Our study involves CBL through comprehension and analysis of adapted scientific articles. We developed a module which integrates metacognitive prompts for guiding students to monitor their understanding and improve their scientific text comprehension. We investigated the effect of these metacognitive prompts on scientific text comprehension as part of CBL in chemistry. About 670 high school chemistry students were randomly divided into three groups exposed to high- and low-intensity CBL. One of the high-intensity groups was also exposed to metacognitive prompts. Research tools included pre- and post-questionnaires aimed at measuring students' conceptual chemistry understanding and metacognitive knowledge in the context of reading strategies, before and after exposure to the CBL. Chemistry understanding was reflected by students' ability to identify the main subject of the adapted article and by explaining concepts both textually and visually. We found that high-intensity CBL combined with metacognitive prompts improved students' chemistry understanding of the adapted scientific articles and the ability to regulate their learning. Our study establishes that reading context-based adapted scientific articles advances students' conceptual chemistry understanding. These gains are strongly amplified by domain-specific metacognitive prompts.  相似文献   

12.
This study compares 183 high school chemistry students' applied and theoretical knowledge of selected concepts based on the particulate theory. The concepts are dissolution, diffusion, effusion, and states of matter. A two-form instrument called the Physical Changes Concepts Test (PCCT) was developed for this study. The application form measures students' knowlege using everyday language. The theoretical form measures students' knowledge using scientific language. Students' formal reasoning ability was measured using the Test Of Logical Thinking (TOLT). The overall results of the two forms of the PCCT indicate that more than 40% of the students displayed alternative conceptions (ACs) of the concepts covered in the PCCT. The study found that students' formal reasoning ability and their preexisting knowledge are associated with their conceptions and use of the particulate theory. The analysis of the nature of students' ACs and their use of the particulate theory revealed a significant difference between students' applied and theoretical knowledge.  相似文献   

13.
In Britain, an emerging slogan in the Labour government's educational policy is 'standards, not structures'. With it may come a discursive shift in the management of the school. Just as educational structures have been marketized, so now there are some signs that school management is itself becoming marketized, thereby revealing an emergent 'common marketing' within the field of education. Although the signs are few within education, within the broader realm of management theory, the indications are stronger. In exploring this, the argument draws upon two concepts from the academic literature on marketing: relationship marketing; and internal marketing. What is common to both modes of marketing is the instrumentalization of the expressive, or the rationalization of the emotions for performative purposes. In relation to these concepts, brief reference is made to recent policy initiatives in the training of headteachers in Britain. In theorizing this, the relevance of Mestrovic's theory of 'postemotional society' is considered.  相似文献   

14.
This paper begins by highlighting the concerns of a number of commentators about what they perceived as an unprecedented incursion of market-oriented instrumental values in higher education in the last quarter of the twentieth century. Bernstein's analysis of these issues is shown to draw upon Durkheimian concepts of the sacred and the profane. Similarities and differences between Durkheim's and Bernstein's definitions of these concepts are examined, and Bernstein's use of them in relation to the formation of pedagogic identities is a major focus of the paper. The second part of the paper examines two particular aspects of Bernstein's exploration of the consequences of growing marketization and managerialization for identity change in education: the displacement of 'singulars' by 'regions', and the introduction of 'generic' pedagogic modes. In both cases, although perhaps to differing degrees, the sacred is displaced and, under certain conditions, the profane 'outer' is in danger of becoming the subjective 'inner'. Bernstein's discussion of generic modes is illustrated by reference to recent changes in teacher training in England and Wales.  相似文献   

15.
In theory, practical work is an established part of university-level chemistry courses. However, mainly due to budget constraints, large class size, time constraints and inadequate teacher preparations, practical activities are frequently left out from chemistry classroom instruction in most developing countries. Small-scale chemistry (SSC) experimentation in which one uses miniature chemical equipment can drastically reduce quantities of chemicals used during experimentation, which can help overcome some of the barriers preventing practical work in the chemistry classroom. This study evaluated the effectiveness of using miniature chemical equipment at the undergraduate level in increasing students’ understanding of chemistry concepts as well as in improving their attitude towards chemistry practical work. Two comparable groups of first-year students who enrolled for a Practical General Chemistry course participated. A quasi-experimental design was employed in which the experimental group (N = 49) used the SSC approach while the control group (N = 52) followed the traditional approach for over 8 weeks. Data were gathered using chemistry tests, attitude and perception questionnaires and interviews. Findings showed that the SSC approach was as effective as the traditional laboratory approach in improving students’ attitude towards practical work, but more effective in enhancing students’ understanding of chemistry concepts. More interestingly, SSC was positively accepted by both students and instructors as an effective strategy for teaching first-year undergraduate chemistry practicals. Some shortcomings of the approach were also identified.  相似文献   

16.

The research reported here derives from the general field of learner-centred teaching and learning, with specific reference to undergraduate chemistry. It documents the use of student-generated questions as diagnostic of their willingness to engage in classroom interactions. It explores four ways of gathering students' written questions and their relative effectiveness. It examines students' capacity to design and present 'quality questions' during phases of their learning and the extent to which these questions are indicative of particular styles of interaction in the classroom, both with tutors and with other students. The results are drawn from data collected through written questions posted into a question box, the 'hits' recorded on a computer software system, and through one-to-one interviews with a sample of 32 students. The results provide an opportunity to discuss the quality of interactions within fairly formalized systems of teaching and learning of chemistry in a university setting and to suggest further research required in this field.  相似文献   

17.
This study focused on the development of a two-tier multiple-choice diagnostic instrument, which was designed and then progressively modified, and implemented to assess students' understanding of solution chemistry concepts. The results of the study are derived from the responses of 756 Grade 11 students (age 16–17) from 14 different high schools who participated in the study. The final version of the instrument included a total of 13 items that addressed the six aspects of solution chemistry, and students' understandings in the test were challenged in multiple contexts with multiple modes and levels of representation. Cronbach alpha reliability coefficients for the content tier and both tiers of the test were found to be 0.697 and 0.748, respectively. Results indicated that a substantial number of students held an inadequate understanding of solution chemistry concepts. In addition, 21 alternative conceptions observed in more than 10% of the students were reported, along with discussion on possible sources of such conceptions.  相似文献   

18.
The instructional influence upon students' conceptions and problem-solving ability of presenting pictures at the molecular level when introducing chemistry concepts and solving chemistry problems was investigated. Before instruction, the Group Assessment of Logical Thinking (GALT) was administered and its score was used as a covariate. For the treatment group, 31 pictorial materials were used during 21 hours of Korean academic high school chemistry classes. For the control group, traditional instruction was used. Six classroom observations (1 hour each in duration) for each group were made. After instruction, the Chemistry Conceptions Test, and the Chemistry Problem-Solving Test (CPST) consisting of 10 pairs of pictorial and algorithmic problems, were administered. Korean students' success on pictorial questions from the CPST was higher than that reported in the literature for college students; however, Korean students did very poorly on algorithmic questions. The GALT score was significantly correlated with students' conceptions and problem-solving ability. Analysis of covariance results indicated that instruction with pictorial materials at the molecular level helped students construct more scientifically correct conceptions than traditional instruction. However, use of the pictorial materials had no facilitating effect on problem-solving ability. © 1997 John Wiley & Sons, Inc. J Res Sci Teach 34: 199–217, 1997.  相似文献   

19.
Both chemistry teachers and nonmajor students appear to agree that freshman chemistry may well be the most problematic traditional science discipline taught in the first year of college—as far as students' misunderstandings, learning difficulties, and misconceptions are concerned. The above is probably due to the many abstract, nonintuitive concepts, which are not directly interrelated. Consequently, in such cases, the powerful, general teaching strategy of “concept mapping” must be replaced by alternative, specific strategies. Selected illustrative examples of students' learning difficulties and misconceptions in freshman general and organic chemistry are presented in the students' terms, followed by the corresponding successfully applied, specific, concept-oriented, eclectic intervention strategies the author uses in order to overcome the difficulties. Based on longitudinal in-class observations, interpretive study, and analysis it is suggested that those students' misconceptions in freshman chemistry which are not interrelated logically and/or derived from one another are not prone to the general “concept mapping” approach and should be dealt with by using the appropriate, specific teaching strategy.  相似文献   

20.
Certain mathematical concepts were not introduced to solve a specific open problem but rather to solve different problems with the same tools in an economic formal way or to unify several approaches: such concepts, as some of those of linear algebra, are presumably difficult to introduce to students as they are potentially interwoven with many types of difficulties as formal ones and far away from the actual knowledge of the students. The purpose of this paper is to propose a methodology for studying the introduction of such concepts in linear algebra during tutorial sessions at the beginning of university, the wording of the concepts being yet presented during lectures. For this purpose, we amend a general methodology of Pariès, Robert and Rogalski inside the general framework of Activity Theory. This methodology lets us take into account several specificities of these concepts and studies the mathematical activity the teacher organises for students and the way he manages the relationship between students’ actual activities and mathematical tasks. We also present an implementation of this methodology based on a French university course to illustrate our approach and discuss its possibilities.  相似文献   

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