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1.
This paper reports the results of a survey of 3006 Year 10–12 students on their understandings of metallic bonding. The instrument was developed based on Chi's ontological categories of scientific concepts and students' understanding of metallic bonding as reported in the literature. The instrument has two parts. Part one probed into students' understanding of metallic bonding as (a) a submicro structure of metals, (b) a process in which individual metal atoms lose their outermost shell electrons to form a ‘sea of electrons’ and octet metal cations or (c) an all-directional electrostatic force between delocalized electrons and metal cations, that is, an interaction. Part two assessed students' explanation of malleability of metals, for example (a) as a submicro structural rearrangement of metal atoms/cations or (b) based on all-directional electrostatic force. The instrument was validated by the Rasch Model. Psychometric assessment showed that the instrument possessed reasonably good properties of measurement. Results revealed that it was reliable and valid for measuring students' understanding of metallic bonding. Analysis revealed that the structure, process and interaction understandings were unidimensional and in an increasing order of difficulty. Implications for the teaching of metallic bonding, particular through the use of diagrams, critiques and model-based learning, are discussed. 相似文献
2.
This study investigated students' interpretation of diagrams representing the human circulatory system. We conducted an interview study with three students aged 14–15 (Year 10) who were studying biology in a Hong Kong school. During the interviews, students were asked to interpret diagrams and relationships between diagrams that represented aspects of the circulatory system. All diagrams used in the interviews had been used by their teacher when teaching the topic. Students' interpretations were expressed by their verbal response and their drawing. Dual coding theory was used to interpret students' responses. There was evidence that one student relied on verbal recall as a strategy in interpreting diagrams. It was found that students might have relied unduly on similarities in spatial features, rather than on deeper meanings represented by conventions, of diagrams when they associated diagrams that represented different aspects of the circulatory system. A pattern of students' understanding of structure–behaviour–function relationship of the biological system was observed. This study suggests the importance of a consistent diagrammatic and verbal representation in communicating scientific ideas. Implications for teaching practice that facilitates learning with diagrams and address students' undue focus on spatial features of diagrams are discussed. 相似文献
3.
Helping students to use and interpret representations in science is critically important if they are to become scientifically literate and able to engage in the discourses related to understanding scientific issues. The purpose of this case-study is to report on how one Year 5 teacher in a small, city school in Brisbane, Australia used different visual, embodied, and language representations to capture students’ engagement in the inquiry tasks. While the case study showed that the students demonstrated clear understandings of the relationships between the different scientific phenomena they were investigating, there is no evidence that these ways of thinking and talking generalised to other inquiry-science topics.However, the case study does provide insights into how this teacher used different visual, embodied, and language strategies to help the students in his class develop complex understandings of the inquiry-science unit they were studying. 相似文献
4.
Emine Adadan Karen E. Irving Kathy C. Trundle 《International Journal of Science Education》2013,35(13):1743-1775
This quasi‐experimental study examined 42 high school introductory chemistry students’ conceptual understandings of the particulate nature of matter (PNM) before and immediately after instruction. Two groups of students, who were taught by the same teacher, received one of two possible instructional interventions: Reform‐Based Teaching (RBT) or Reform‐Based Teaching with Multiple Representations (RBTw/MR). The RBTw/MR instruction differed from the RBT instruction in terms of the frequency of using multiple representations (visual, textual, oral) in relationship to the macroscopic phenomenon and the likely actions occurring at the submicroscopic level. Qualitative research methods, including open‐ended questionnaires and interviews, were used to investigate and describe participants’ conceptual understandings of the PNM over time. The findings indicated that before instruction all participants held a range of alternative conceptions about the aspects of the PNM. Post‐instruction findings indicate that the RBTw/MR instruction was more efficacious in promoting a scientific understanding of the PNM than was the instruction without multiple representations. 相似文献
5.
Understanding bonding is fundamental to success in chemistry. A number of alternative conceptions related to chemical bonding have been reported in the literature. Research suggests that many alternative conceptions held by chemistry students result from previous teaching; if teachers are explicit in the use of representations and explain their content-specific forms and functions, this might be avoided. The development of an understanding of and ability to use multiple representations is crucial to students’ understanding of chemical bonding. This paper draws on data from a larger study involving two Year 11 chemistry classes (n = 27, n = 22). It explores the contribution of explicit instruction about multiple representations to students’ understanding and representation of chemical bonding. The instructional strategies were documented using audio-recordings and the teacher-researcher’s reflection journal. Pre-test–post-test comparisons showed an improvement in conceptual understanding and representational competence. Analysis of the students’ texts provided further evidence of the students’ ability to use multiple representations to explain macroscopic phenomena on the molecular level. The findings suggest that explicit instruction about representational form and function contributes to the enhancement of representational competence and conceptual understanding of bonding in chemistry. However, the scaffolding strategies employed by the teacher play an important role in the learning process. This research has implications for professional development enhancing teachers’ approaches to these aspects of instruction around chemical bonding. 相似文献
6.
Bruce Waldrip Vaughan Prain 《International Journal of Science and Mathematics Education》2012,10(5):1191-1213
There is growing research interest in the challenges and opportunities learners face in representing scientific understandings, processes and reasoning. These challenges include integrating verbal, visual and mathematical modes in science discourse to make strong conceptual links between representations and classroom experiences. Our paper reports on a project that aimed to identify practical and theoretical issues entailed in a representation-intensive approach to guiding students’ conceptual learning in science. We focus here on a teacher developing students’ understanding of the formation of ions and molecules. We argue that the representations produced by students in this process met the criteria for representational competence proposed by diSessa (Cognition and Instruction, 22, 293–331, 2004) and Kozma & Russell (2005). The students understood that an effective representation needed to show relevant information, focus on pertinent points, be self-sufficient in its claims about the topic and provide coherent links between different parts of the representation. The final activity showed that their representations reached Kozma & Russell’s (2005) highest level of competence, where the students were able to use specific features of their representations to critique their suitability for explaining bonding and were able to show how their representation linked to the periodic table as a representation. We conclude by considering the implications of these findings. 相似文献
7.
This study examined teachers’ and students’ initial conceptions of computer-based models—Flash and NetLogo models—and documented how teachers and students reconciled notions of multiple representations featuring macroscopic, submicroscopic and symbolic representations prior to actual intervention in eight high school chemistry classrooms. Individual in-depth interviews were conducted with 32 students and 6 teachers. Findings revealed an interplay of complex factors that functioned as opportunities and obstacles in the implementation of technologies in science classrooms. Students revealed preferences for the Flash models as opposed to the open-ended NetLogo models. Altogether, due to lack of content and modeling background knowledge, students experienced difficulties articulating coherent and blended understandings of multiple representations. Concurrently, while the aesthetic and interactive features of the models were of great value, they did not sustain students’ initial curiosity and opportunities to improve understandings about chemistry phenomena. Most teachers recognized direct alignment of the Flash model with their existing curriculum; however, the benefits were relegated to existing procedural and passive classroom practices. The findings have implications for pedagogical approaches that address the implementation of computer-based models, function of models, models as multiple representations and the role of background knowledge and cognitive load, and the role of teacher vision and classroom practices. 相似文献
8.
The case‐based computerized laboratory (CCL) is a chemistry learning environment that integrates computerized experiments with emphasis on scientific inquiry and comprehension of case studies. The research objective was to investigate chemical understanding and graphing skills of high school honors students via bidirectional visual and textual representations in the CCL learning environment. The research population of our 3‐year study consisted of 857 chemistry 12th grade honors students from a variety of high schools in Israel. Pre‐ and postcase‐based questionnaires were used to assess students' graphing and chemical understanding–retention skills. We found that students in the CCL learning environment significantly improved their graphing skills and chemical understanding–retention in the post‐ with respect to the prequestionnaires. Comparing the experimental students to their non‐CCL control peers has shown that CCL students had an advantage in graphing skills. The CCL contribution was most noticeable for experimental students of relatively low academic level who benefit the most from the combination of visual and textual representations. Our findings emphasize the educational value of combining the case‐based method with computerized laboratories for enhancing students' chemistry understanding and graphing skills, and for developing their ability to bidirectionally transfer between textual and visual representations. © 2008 Wiley Periodicals, Inc. J Res Sci Teach 45: 219–250, 2008. 相似文献
9.
Anna Bergqvist Michal Drechsler Shu-Nu Chang Rundgren 《International Journal of Science Education》2016,38(2):298-318
Researchers have shown a growing interest in science teachers’ professional knowledge in recent decades. The article focuses on how chemistry teachers impart chemical bonding, one of the most important topics covered in upper secondary school chemistry courses. Chemical bonding is primarily taught using models, which are key for understanding science. However, many studies have determined that the use of models in science education can contribute to students’ difficulties understanding the topic, and that students generally find chemical bonding a challenging topic. The aim of this study is to investigate teachers’ knowledge of teaching chemical bonding. The study focuses on three essential components of pedagogical content knowledge (PCK): (1) the students’ understanding, (2) representations, and (3) instructional strategies. We analyzed lesson plans about chemical bonding generated by 10 chemistry teachers with whom we also conducted semi-structured interviews about their teaching. Our results revealed that the teachers were generally unaware of how the representations of models they used affected student comprehension. The teachers had trouble specifying students’ difficulties in understanding. Moreover, most of the instructional strategies described were generic and insufficient for promoting student understanding. Additionally, the teachers’ rationale for choosing a specific representation or activity was seldom directed at addressing students’ understanding. Our results indicate that both PCK components require improvement, and suggest that the two components should be connected. Implications for the professional development of pre-service and in-service teachers are discussed. 相似文献
10.
Vaughan Prain Russell Tytler Suzanne Peterson 《International Journal of Science Education》2013,35(6):787-808
There has been extensive research on children’s understanding of evaporation, but representational issues entailed in this understanding have not been investigated in depth. This study explored three students’ engagement with science concepts relating to evaporation through various representational modes, such as diagrams, verbal accounts, gestures, and captioned drawings. This engagement entailed students (a) clarifying their thinking through exploring representational resources; (b) developing understanding of what these representations signify; and (c) learning how to construct representational aspects of scientific explanation. The study involved a sequence of classroom lessons on evaporation and structured interviews with nine children, and found that a focus on representational challenges provided fresh insights into the conceptual task involved in learning science. The findings suggest that teacher‐mediated negotiation of representational issues as students construct different modal accounts can support enriched learning by enabling both (a) richer conceptual understanding by students; and (b) enhanced teacher insights into students’ thinking. 相似文献
11.
There is growing research interest in both the challenges and opportunities learners face in trying to represent scientific
understanding, processes and reasoning. These challenges are increasingly well understood by researchers, including integrating
verbal, visual and mathematical modes in science discourse, and making strong conceptual links between classroom experiences
and diverse 3D and 2D representations. However, a matching enhanced pedagogy of representation-rich learning opportunities,
including their theoretical justification, is much less clearly established. Our paper reports on part of a three-year project
to identify practical and theoretical issues entailed in developing a pedagogical framework to guide teacher understanding
and practices to maximize representational opportunities for learners to develop conceptual understandings in science. 相似文献
12.
The present study focused on investigating the effectiveness of instruction via newly developed teaching materials based on
cooperative learning when compared to a traditional approach, on ninth grade students’ understanding of metallic bonding.
Fifty-seven ninth grade science students from two science classes in the same high school participated in this study. The
same teacher taught metallic bonding with cooperative learning to an experimental group (N = 28) and with a traditional teacher centred approach to a control group (N = 29). Students’ conceptual understanding of metallic bonding was measured using the Metallic Bonding Concept Test. The results
from the Student’s t test indicated that the mean score of the students in the experimental group was significantly higher in the experimental
group (78.60, SD = 8.62), than in the control group (54.33, SD = 9.11) after treatment. In the light of the results from the
concept test and individual interviews, the misconceptions related to metallic bonding were found less in the experimental
group than traditional. Five of these misconceptions were firstly identified in this study. The individual interviews which
were done with students from experimental group immediately after the instruction showed that students had positive perceptions
about their cooperative work experiences. 相似文献
13.
14.
Paul J. Bischoff Leanne Avery Constance Feldt Golden Paul French 《Journal of Science Teacher Education》2010,21(4):411-429
The purpose of this study was to investigate the development of preservice science teachers’ knowledge structures in the domain
of oxidation and reduction chemistry. Knowledge structures were elicited through video-recorded semi-structured interviews
before and after the unit of instruction, and analyzed using a visual flow map representation. Paralleling these interviews,
the preservice teachers were tasked with diagnosing middle school students’ scientific understandings. Data analyzed quantitatively
and qualitatively showed large variation in knowledge structure complexity across the preservice teachers, strong correlations
between measures of knowledge structure and diversity (as defined by the Shannon Wiener diversity index), and the development
of more balanced knowledge structure representations. For most preservice teachers, their diagnostic scores of the middle
school students showed a small increase. 相似文献
15.
Developing pre-service science teachers’ epistemic insight remains a challenge, despite decades of research in related bodies of work such as the nature of science (NOS) in science education. While there may be numerous aspects to this problem, one critical element is that the NOS is a meta-concept that demands higher-order cognitive skills. One possible strategy to facilitate pre-service teachers’ understanding of epistemic aspects of science is visualisation. Visual representations of objects and processes can be tools for developing and monitoring understanding. Although the NOS and visualisation literatures have been studied extensively, the intersection of these bodies of literatures has been minimal. Incorporating visual tools on the NOS in teacher education is likely to facilitate teachers’ learning, eventually impacting their students’ learning of the NOS. The objective of this paper is to illustrate how the visual tools of scientific knowledge and practices aspects of the NOS can be integrated in science teacher education in order to develop pre-service teachers’ epistemic insight. The paper presents an empirical study that incorporated visual tools about the NOS in primary science teacher education. Data on 14 pre-service teachers’ are presented along with in-depth case studies of 3 pre-service teachers illustrating the influence of the teacher education intervention. The qualitative analysis of visual representations before and after the intervention as well as verbal data suggests that there was improvement in pre-service teachers’ perceptions of the NOS. Implications for future research on visualisation of the NOS are discussed. 相似文献
16.
Many students have difficulty learning symbolic and molecular representations of chemistry. This study investigated how students developed an understanding of chemical representations with the aid of a computer‐based visualizing tool, eChem, that allowed them to build molecular models and view multiple representations simultaneously. Multiple sources of data were collected with the participation of 71 eleventh graders at a small public high school over a 6‐week period. The results of pre‐ and posttests showed that students' understanding of chemical representations improved substantially (p < .001, effect size = 2.68‐. The analysis of video recordings revealed that several features in eChem helped students construct models and translate representations. Students who were highly engaged in discussions while using eChem made referential linkages between visual and conceptual aspects of representations. This in turn may have deepened their understanding of chemical representations and concepts. The findings also suggest that computerized models can serve as a vehicle for students to generate mental images. Finally, students demonstrated their preferences of certain types of representations and did not use all types of three‐dimensional models interchangeably. © 2001 John Wiley & Sons, Inc. J Res Sci Teach 38: 821–842, 2001 相似文献
17.
Volunteer non-major chemistry students taking an introductory university chemistry course (n = 17) were interviewed about their understanding of a variety of chemical diagrams. All the students’ interviewed appreciated
that diagrams of laboratory equipment were useful to show how to set up laboratory equipment. However students’ ability to
explain specific diagrams at either the macroscopic or sub-microscopic level varied greatly. The results highlighted the poor
level of understanding that some students had even after completing both exercises and experiments using the diagrams. The
connection between the diagrams of the macroscopic level (equipment, chemicals), the sub-microscopic level (molecular) and
the symbolic level (equations) was not always considered explicitly by students. The results indicate a need for chemical
diagrams to be used carefully and more explicitly to ensure learner understanding. Correspondingly, students need to interpret
visual chemical diagrams using meta-visualization skills linking the various levels of representation, and appreciating the
role of the diagrams in explanations need to be developed. 相似文献
18.
Students at the junior high school (JHS) level often cannot use their knowledge of physics for explaining and predicting phenomena. We claim that this difficulty stems from the fact that explanations are multi‐step reasoning tasks, and students often lack the qualitative problem‐solving strategies needed to guide them. This article describes a new instructional approach for teaching mechanics at the JHS level that explicitly teaches such a strategy. The strategy involves easy to use visual representations and leads from characterizing the system in terms of interactions to the design of free‐body force diagrams. These diagrams are used for explaining and predicting phenomena based on Newton's laws. The findings show that 9th grade students who studied by the approach advanced significantly from pretests to post‐tests on items of the Force Concept Inventory—FCI and on other items examining specific basic and complex understanding performances. These items focused on the major learning goals of the program. In the post‐tests the JHS students performed on the FCI items better than advanced high‐school and college students. In addition, interviews conducted before, during, and after instruction indicated that the students had an improved ability to explain and predict phenomena using physics ideas and that they showed retention after 6 months. © 2010 Wiley Periodicals, Inc. J Res Sci Teach 47: 1094–1115, 2010 相似文献
19.
Gülüzar Eymur Ömer Geban 《International Journal of Science and Mathematics Education》2017,15(5):853-871
The main purpose of this study was to investigate the effects of cooperative learning based on conceptual change approach instruction on ninth-grade students’ understanding in chemical bonding concepts compared to traditional instruction. Seventy-two ninth-grade students from two intact chemistry classes taught by the same teacher in a public high school participated in the study. The classes were randomly assigned as the experimental and control group. The control group (N?=?35) was taught by traditional instruction while the experimental group (N?=?37) was taught cooperative learning based on conceptual change approach instruction. Chemical Bonding Concept Test (CBCT) was used as pre- and post-test to define students’ understanding of chemical bonding concepts. After treatment, students’ interviews were conducted to observe more information about their responses. Moreover, students from experimental groups were interviewed to obtain information about students’ perceptions on cooperative work experiences. The results from ANCOVA showed that cooperative learning based on conceptual change approach instruction led to better acquisition of scientific conceptions related to chemical bonding concepts than traditional instruction. Interview results demonstrated that the students in the experimental group had better understanding and fewer misconceptions in chemical bonding concepts than those in the control group. Moreover, interviews about treatment indicated that this treatment helped students’ learning and increased their learning motivation and their social skills. 相似文献
20.
Jazilah Othman David F. Treagust A. L. Chandrasegaran 《International Journal of Science Education》2013,35(11):1531-1550
A thorough understanding of chemical bonding requires familiarity with the particulate nature of matter. In this study, a two‐tier multiple‐choice diagnostic instrument consisting of ten items (five items involving each of the two concepts) was developed to assess students’ understanding of the particulate nature of matter and chemical bonding so as to identify possible associations between students’ understandings of the two concepts. The instrument was administered to 260 Grades 9 and 10 students (15–16 years old) from a secondary school in Singapore. Analysis of students’ responses revealed several alternative conceptions about the two concepts. In addition, analysis of six pairs of items suggested that students’ limited understanding of the particulate nature of matter influenced their understanding of chemical bonding. The findings provide useful information for challenging students’ alternative conceptions about the particulate nature of matter during classroom instruction in order to enable them to achieve better understanding of chemical bonding. 相似文献