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1.
One of the factors affecting students' learning in science is their existing knowledge prior to instruction. The students' prior knowledge provides an indication of the alternative conceptions as well as the scientific conceptions possessed by the students. This study is concerned primarily with students' alternative conceptions and with instructional strategies to effect the learning of scientific conceptions; i.e., to effect conceptual change from alternative to scientific conceptions. The conceptual change model used here suggests conditions under which alternative conceptions can be replaced by or differentiated into scientific conceptions and new conceptions can be integrated with existing conceptions. The instructional strategy and materials were developed for a particular student population, namely, black high school students in South Africa, using their previously identified prior knowledge (conceptions and alternative conceptions) and incorporate the principles for conceptual change. The conceptions involved were mass, volume, and density. An experimental group of students was taught these concepts using the special instructional strategy and materials. A control group was taught the same concepts using a traditional strategy and materials. Pre- and posttests were used to assess the conceptual change that occurred in the experimental and control groups. The results showed a significantly larger improvement in the acquisition of scientific conceptions as a result of the instructional strategy and materials which explicitly dealt with student alternative conceptions.  相似文献   

2.
The process of students' conceptual change was investigated during a computer‐supported physics unit in a Grade 10 science class. Computer simulation programs were developed to confront students' alternative conceptions in mechanics. A conceptual test was administered as a pre‐, post‐, and delayed posttest to determine students' conceptual change. Students worked collaboratively in pairs on the programs carrying out predict–observe–explain tasks according to worksheets. While the pairs worked on the tasks, their conversational interactions were recorded. A range of other data was collected at various junctures during instruction. At each juncture, the data for each of 12 students were analyzed to provide a conceptual snapshot at that juncture. All the conceptual snapshots together provided a delineation of the students' conceptual development. It was found that many students vacillated between alternative and scientific conceptions from one context to another during instruction, i.e., their conceptual change was context dependent and unstable. The few students who achieved context independent and stable conceptual change appeared to be able to perceive the commonalities and accept the generality of scientific conceptions across contexts. These findings led to a pattern of conceptual change which has implications for instructional practices. The article concludes with consequent implications for classsrooms. © 1999 John Wiley & Sons, Inc. J Res Sci Teach 36: 859–882, 1999  相似文献   

3.
This study was based on the framework of the “conflict map” to facilitate student conceptual learning about causes of the seasons. Instruction guided by the conflict map emphasizes not only the use of discrepant events, but also the resolution of conflict between students' alternative conceptions and scientific conceptions, using critical events or explanations and relevant perceptions and conceptions that explicate the scientific conceptions. Two ninth grade science classes in Taiwan participated in this quasi‐experimental study in which one class was assigned to a traditional teaching group and the other class was assigned to a conflict map instruction treatment. Students' ideas were gathered through three interviews: the first was conducted 1 week after the instruction; the second 2 months afterward; and the third at 8 months after the treatment. Through an analysis of students' interview responses, it was revealed that many students, even after instruction, had a common alternative conception that seasons were determined by the earth's distance to the sun. However, the instruction guided by the framework of the conflict map was shown to be a potential way of changing the alternative conception and acquiring scientific understandings, especially in light of long‐term observations. A detailed analysis of students' ideas across the interviews also strongly suggests that researchers as well as practicing teachers need to pay particular attention to those students who can simply recall the scientific fact without deep thinking, as these students may learn science through rote memorization and soon regress to alternative conceptions after science instruction. © 2005 Wiley Periodicals, Inc. J Res Sci Teach 42: 1089–1111, 2005  相似文献   

4.
This study examined 10th‐grade students' use of theory and evidence in evaluating a socio‐scientific issue: the use of underground water, after students had received a Science, Technology and Society‐oriented instruction. Forty‐five male and 45 female students from two intact, single‐sex, classes participated in this study. A flow‐map method was used to assess the participants' conceptual knowledge. The reasoning mode was assessed using a questionnaire with open‐ended questions. Results showed that, although some weak to moderate associations were found between conceptual organization in memory and reasoning modes, the students' ability to incorporate theory and evidence was in general inadequate. It was also found that students' reasoning modes were consistent with their epistemological perspectives. Moreover, male and female students appear to have different reasoning approaches.  相似文献   

5.
The purpose of this study was two-fold: (1) to understand the conceptual frameworks that sixth-grade students use to explain the nature of matter and molecules, and (2) to assess the effectiveness of two alternative curriculum units in promoting students' scientific understanding. The study involved 15 sixth-grade science classes taught by 12 teachers in each of two successive years. Data were collected through paper-and-pencil tests and clinical interviews. The results revealed that students' entering conceptions differed from scientific conceptions in various ways. These differences included molecular conceptions concerning the nature, arrangement, and motion of molecules as well as macroscopic conceptions concerning the nature of matter and its physical changes. The results also showed that the students taught by the revised unit in Year 2 performed significantly better than the students taught by the original commercial curriculum unit in Year 1 for 9 of the 10 conceptual categories. Implications for science teaching and curriculum development are discussed.  相似文献   

6.
This study, conducted in an inner-city middle school, followed the conceptual changes shown in 25 students' writing over a 12-week science unit. Conceptual changes for 6 target students are reported. Student understanding was assessed regarding the nature of matter and physical change by paper-and-pencil pretest and posttest. The 6 target students were interviewed about the goal concepts before and after instruction. Students' writing during lesson activities provided qualitative data about their understandings of the goal concepts across the science unit. The researcher constructed concept maps from students' written statements and compared the maps across time to assess changes in the schema of core concepts, complexity, and organization as a result of instruction. Target students' changes were studied in detail to determine patterns of conceptual change. After patterns were located in target students' maps, the remaining 19 students' maps were analyzed for similar patterns. The ideas that students identified in their writing showed changes in central concepts, complexity, and organization as the lessons progressed. When instructional events were analyzed in relation to students' demonstrated ideas, understanding of the goal conceptions appeared in students' writing more often when students had opportunities to explain their new ideas orally and in writing.  相似文献   

7.
This study evaluated the effects of cooperative learning on students' verbal interaction patterns and achievement in a conceptual change instructional model in secondary science. Current conceptual change instructional models recognize the importance of student–student verbal interactions, but lack specific strategies to encourage these interactions. Cooperative learning may provide the necessary strategies. Two sections of low-ability 10th-grade students were designated the experimental and control groups. Students in both sections received identical content instruction on the particle model of matter using conceptual change teaching strategies. Students worked in teacher-assigned small groups on in-class assignments. The experimental section used cooperative learning strategies involving instruction in collaborative skills and group evaluation of assignments. The control section received no collaborative skills training and students were evaluated individually on group work. Gains on achievement were assessed using pre- and posttreatment administrations of an investigator-designed short-answer essay test. The assessment strategies used in this study represent an attempt to measure conceptual change. Achievement was related to students' ability to correctly use appropriate scientific explanations of events and phenomena and to discard use of naive conceptions. Verbal interaction patterns of students working in groups were recorded on videotape and analyzed using an investigator-designed verbal interaction scheme. The targeted verbalizations used in the interaction scheme were derived from the social learning theories of Piaget and Vygotsky. It was found that students using cooperative learning strategies showed greater achievement gains as defined above and made greater use of specific verbal patterns believed to be related to increased learning. The results of the study demonstrated that cooperative learning strategies enhance conceptual change instruction. More research is needed to identify the specific variables mediating the effects of cooperative learning strategies on conceptual change learning. The methods employed in this study may provide some of the tools for this research.  相似文献   

8.
The effects of both computer animations of microscopic chemical processes occurring in a galvanic cell and conceptual change instruction based on chemical demonstrations on students' conceptions of current flow in electrolyte solutions were investigated. Preliminary results for verbal conceptual questions suggest that conceptual change instruction was effective at dispelling student misconceptions that electrons flow in aqueous solutions of electrochemical cells. Computer animations did not appear to have an effect on students' responses to visual or verbal conceptual questions. An animation/conceptual change interaction for verbal conceptual questions suggests that animations may prove distacting when the questions do not require students to visualize. Data from this study also suggests that lecture attendance and recitation participations helped students answer visual questions.  相似文献   

9.
Scientific literacy implies an adequate understanding of the nature of scientific knowledge. However, little is known about classroom factors that can influence students' conceptions of the nature of science. In the present study, classroom variables that were related to changes in students' conceptions of science were identified. Particular attention was directed toward students' overall conceptions of scientific knowledge and their views of its tentative nature. Twenty-five classroom variables were found to be significantly related to both overall and tentative conceptions, while 12 variables were found to be scale-specific. A comparison between teacher and student conceptions of science did not support the prevalent assumption that a teacher's conception of science is significantly related to changes in students' conceptions of science. “Successful” classes were defined as those exhibiting the greatest student conceptual changes toward the viewpoint held by the teacher, irrespective of the “adequacy” of the teacher's viewpoint. In general, these classes were typified by frequent inquiry-oriented questioning with little emphasis on rote memory. Implicit references to the nature of science were commonly observed. Furthermore, where greatest changes in student conceptions of science were observed, the teachers were pleasant, supportive, and frequently used anecdotes to promote instruction and establish rapport. Emphasis on the depth, breadth, and accuracy of content statistically differentiated between “successful” and “unsuccessful” classes with respect to students' overall conceptions. However, this emphasis on content presentation did not differentiate classes with respect to students' conceptions of the tentative nature of science.  相似文献   

10.
This study investigated the conceptual pathways of 19 Grade 11 introductory chemistry students (age 16–17) as they participated in a multirepresentational instruction on the particulate nature of matter (PNM). This study was grounded in contemporary conceptual change theory, in particular, research on students' conceptual pathways that focuses on the interaction between students' existing conceptions and instruction, which might give rise to observing multiple paths. This mixed method study combined a quantitative research design with qualitative data collection and analysis methods. Data were collected through open‐ended questionnaires, interviews, and document analysis to portray the patterns of students' conceptual pathways of the PNM from pre to postinstruction to 3 months after the instruction. An interpretive analysis of the qualitative data revealed six different conceptual pathways varying between radical progress and no additional progress (stable) after the multirepresentational instruction and between stable (no change) and full decay over a 3‐month period following the instruction. The identified patterns of conceptual pathways provide information about the manner in which conceptual change occurred, as well as suggest potential implications for instructional practices. © 2010 Wiley Periodicals, Inc. J Res Sci Teach 47: 1004–1035, 2010  相似文献   

11.
Inquiry instruction often neglects graphing. It gives students few opportunities to develop the knowledge and skills necessary to take advantage of graphs, and which are called for by current science education standards. Yet, it is not well known how to support graphing skills, particularly within middle school science inquiry contexts. Using qualitative graphs is a promising, but underexplored approach. In contrast to quantitative graphs, which can lead students to focus too narrowly on the mechanics of plotting points, qualitative graphs can encourage students to relate graphical representations to their conceptual meaning. Guided by the Knowledge Integration framework, which recognizes and guides students in integrating their diverse ideas about science, we incorporated qualitative graphing activities into a seventh grade web-based inquiry unit about cell division and cancer treatment. In Study 1, we characterized the kinds of graphs students generated in terms of their integration of graphical and scientific knowledge. We also found that students (n = 30) using the unit made significant learning gains based on their pretest to post-test scores. In Study 2, we compared students' performance in two versions of the same unit: One that had students construct, and second that had them critique qualitative graphs. Results showed that both activities had distinct benefits, and improved students' (n = 117) integrated understanding of graphs and science. Specifically, critiquing graphs helped students improve their scientific explanations within the unit, while constructing graphs led students to link key science ideas within both their in-unit and post-unit explanations. We discuss the relative affordances and constraints of critique and construction activities, and observe students' common misunderstandings of graphs. In all, this study offers a critical exploration of how to design instruction that simultaneously supports students' science and graph understanding within complex inquiry contexts.  相似文献   

12.
This article explores the conceptual change of students in Grades 10 and 12 in three Australian senior high schools when the teachers included computer multimedia to a greater or lesser extent in their teaching of a genetics course. The study, underpinned by a multidimensional conceptual‐change framework, used an interpretive approach and a case‐based design with multiple data collection methods. Over 4–8 weeks, the students learned genetics in classroom lessons that included BioLogica activities, which feature multiple representations. Results of the online tests and interview tasks revealed that most students improved their understanding of genetics as evidenced in the development of genetics reasoning. However, using Thorley's (1990) status analysis categories, a cross‐case analysis of the gene conceptions of 9 of the 26 students interviewed indicated that only 4 students' postinstructional conceptions were intelligible–plausible–fruitful. Students' conceptual change was consistent with classroom teaching and learning. Findings suggested that multiple representations supported conceptual understanding of genetics but not in all students. It was also shown that status can be a viable hallmark enabling researchers to identify students' conceptual change that would otherwise be less accessible. Thorley's method for analyzing conceptual status is discussed. © 2006 Wiley Periodicals, Inc. J Res Sci Teach 44: 205–235, 2007  相似文献   

13.
The purpose of this study was to investigate the effects of the Common Knowledge Construction Model (CKCM) lesson sequence, an intervention based both in conceptual change theory and in Phenomenography, a subset of conceptual change theory. A mixed approach was used to investigate whether this model had a significant effect on 7th grade students' science achievement and conceptual change. The Excretion Unit Achievement Test (EUAT) indicated that students (N = 33) in the experimental group achieved significantly higher scores (p < 0.001) than students in the control group (N = 35) taught by traditional teaching methods. Qualitative analysis of students' pre‐ and post‐teaching conceptions of excretion revealed (1) the addition and deletion of ideas from pre‐ to post‐teaching; (2) the change in the number of students within categories of ideas; (3) the replacement of everyday language with scientific labels; and (4) the difference in the complexity of students' responses from pre‐ to post‐teaching. These findings contribute to the literature on teaching that incorporates students' conceptions and conceptual change. © 2009 Wiley Periodicals, Inc. J Res Sci Teach 47: 25–46, 2010  相似文献   

14.
This longitudinal study investigated the progression in junior high school (JHS) students' conceptions of the structure of matter while studying a new instructional approach dealing with “Materials.” In particular, we studied the progression of students' learning along two dimensions: (a) the conceptual model; and (b) the context of application. Students were asked to draw the structure of several materials and to write their explanations about the structure of these materials in questionnaires administered five times during a 3‐year period. Results indicate students' progression in their microscopic conceptualization of materials. Toward the end of the instruction about 85% of the students used a microscopic model in their representations, and 36% were able to give a molecular model. About 83% of the students retained a microscopic model. Different profiles of JHS students' progression in the conception of the structure of matter were identified. The study suggests that a long‐term development of the particulate model requires: (a) constructing a solid foundation of knowledge about microscopic structure of materials; and (b) a spiral instruction. © 2007 Wiley Periodicals, Inc. J Res Sci Teach 45: 132–152, 2008  相似文献   

15.
An understanding of mechanical waves is a pre‐requisite for the study of many topics in advanced physics, and indeed in many other disciplines. There have been many research studies in mechanical waves, all of which have revealed that students have trouble with the basic concepts. Therefore, in order for teachers to prepare appropriate instruction for their classes, it is useful to diagnose their students' conceptions—if possible before they enter class. It is for this purpose that many diagnostic instruments have been developed, often in the form of multiple‐choice tests. In this study, we have used the open‐ended Wave Diagnostic Test to develop a multiple‐choice conceptual survey in an evolutionary manner. The two‐year development procedure included open‐ended surveys and interviews involving 299 Thai students and 88 Australian students. The final version, called the Mechanical Waves Conceptual Survey, has been administered to 632 Australian students from high school to second‐year university and 270 Thai high school students. Standard statistical analyses show that the survey is reliable and valid. Further validity checks, including consultation with experts, were also carried out. The survey has four subtopics—propagation, superposition, reflection, and standing waves—and the teachers can choose the subtopics relevant for their students. In this paper we also demonstrate the use of a typical survey question to test students' conceptual understanding and identify common alternative conceptions.  相似文献   

16.
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   

17.
ABSTRACT

Graduate students regularly teach undergraduate STEM courses and can positively impact students’ understanding of science. Yet little research examines graduate students’ knowledge about nature of science (NOS) or instructional strategies for teaching graduate students about NOS. This exploratory study sought to understand how a 1-credit Teaching in Higher Education course that utilised an explicit, reflective, and mixed-context approach to NOS instruction impacted STEM graduate students’ NOS conceptions and teaching intentions. Participants included 13 graduate students. Data sources included the Views of Nature of Science (VNOS-Form C) questionnaire administered pre- and post-instruction, semi-structured interviews with a subset of participants, and a NOS-related course project. Prior to instruction participants held many alternative NOS conceptions. Post-instruction, participants’ NOS conceptions improved substantially, particularly in their understandings of theories and laws and the tentative nature of scientific knowledge. All 12 participants planning to teach NOS intended to use explicit instructional approaches. A majority of participants also integrated novel ideas to their intended NOS instruction. These results suggest that a teaching methods course for graduate students with embedded NOS instruction can address alternative NOS conceptions and facilitate intended use of effective NOS instruction. Future research understanding graduate students' NOS understandings and actual NOS instruction is warranted.  相似文献   

18.
The purpose of this study was to explore students' knowledge and learning of the human nervous system (HNS) in an introductory undergraduate Human Anatomy and Physiology course. Classroom observations, demographic data, a preinstructional unit test with drawings, and a postinstructional unit test with drawings were used to identify students' overall knowledge and learning during the unit of study. Quantitative and qualitative analysis indicate that students have an initially poor understanding of the nervous system with many prevailing alternative conceptions. These alternative conceptions include both structural and functional components and often incorporate colloquial use of language. Findings reveal students include the heart as a major component of the HNS, a reflex arc illustrated by the action rather than structure, and types of neurons (unipolar, bipolar, or multipolar) differentiated by charge or number of cell bodies rather than structural arrangement. Classroom instruction coupled with concurrent laboratory participation provided experiences for students to overcome some of their alternative conceptions. The finding of this research suggest that instructors should be aware of the students' prevailing alternative conceptions prior to instruction and that use of drawings as a formative assessment tool is an excellent way to collect such information. Anat Sci Educ 3:227–233, 2010. © 2010 American Association of Anatomists.  相似文献   

19.
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   

20.
Based on a purposive sample of 15 second‐year chemical engineering students, this study investigates students' conceptions of evaporation, condensation and vapour pressure. During individual interviews the students were questioned on three tasks that had been designed around these topics. Qualitative analysis of student responses showed a range of conceptions in each area, including some misconceptions. A key underlying misconception was the belief that evaporation and condensation require a temperature gradient in order to take place. Many students changed their initial (incorrect) answers when presented with further physical evidence as the interview progressed. The study points to the importance not only of practical work, but of associated conceptual discussions that allow students to reflect on and refine their conceptions.  相似文献   

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