首页 | 本学科首页   官方微博 | 高级检索  
相似文献
 共查询到20条相似文献，搜索用时 640 毫秒
1.
A sample of 100 students from junior high school physical science, high school chemistry, and introductory college chemistry were examined for understanding of five chemistry concepts. The concepts addressed were chemical change, dissolution of a solid in water, conservation of atoms, periodicity, and phase change. The amount of experience with the concepts (grade level) and reasoning ability (developmental level) were examined as possible sources of variation in student understanding. Differences in understanding with respect to grade level were found to be significant for the concepts of chemical change, dissolution of a solid, conservation of atoms, and periodicity. However, few of the students in the college chemistry sample exhibited sound understanding of chemical change, periodicity, or phase change. The use of particulate terms (atoms, ions, molecules) increased across the grade levels. Reasoning ability proved to be a significant factor for student understanding of conservation of atoms and periodicity. An examination of the number and types of misconceptions across the grade levels revealed several interesting patterns and suggested sources for the students' alternative conceptions.  相似文献   

2.
Submicrorepresentations (SMR) could be an important element, not only for explaining the experimental observations to students, but also in the process of evaluating students’ knowledge and identifying their chemical misconceptions. This study investigated the level of students’ understanding of the solution concentration and the process of dissolving ionic and molecular crystals at particulate level, and identifies possible misconceptions about this process. Altogether 408 secondary school students (average age 16.3) participated in the study. The test of chemical knowledge was applied and the analysis of four selected problems related to drawing SMRs in solution chemistry is presented. Selected students were also interviewed in order to gain more detailed data about their way of solving problems comprised in the knowledge test. The average achievement on solution chemistry items was only 43%. It can be concluded from the results that students have different misconceptions about arrangements of solute particles in the solution and presentation of its concentration at particulate level. Students show quite low achievement scores on the problem regarding drawing the SMR of ionic substance aqueous solution (7.6% correct answers) and even lower ones on the problem regarding drawing the SMR of diluted and saturated aqueous solutions of molecular crystal (no completely correct answers). It can be also concluded that many different misconceptions concerning the particulate level of basic solution chemistry concepts can be identified. In the conclusion some implications for teaching to reach a higher level of understanding of solution chemistry are proposed.  相似文献   

3.
This study replicates, with additions, research done by Garnett and Treagust. Garnett and Treagust's interview questions for galvanic and electrolytic cells were used with modifications; concentration cell questions were asked in a similar manner. These questions were administered to 16 introductory college chemistry students after electrochemistry instruction. Student misconceptions most commonly encountered included notions that electrons flow through the salt bridge and electrolyte solutions to complete the circuit, plus and minus signs assigned to the electrodes represent net electronic charges, and water is unreactive in the electrolysis of aqueous solutions. New misconceptions identified included notions that half-cell potentials are absolute and can be used to predict the spontaneity of individual half-cells, and electrochemical cell potentials are independent of ion concentrations. Most students demonstrating misconceptions were still able to calculate cell potentials correctly, which is consistent with research suggesting that students capable of solving quantitative examination problems often lack an understanding of the underlying concepts. Probable origins of these student misconceptions were attributed to students being unaware of the relative nature of electrochemical potentials and chemistry textbooks making misleading and incorrect statements. A minor technical flaw in the Garnett and Treagust study is also addressed. J Res Sci Teach 34: 377–398, 1997.  相似文献   

4.
Lebanese educators claim that middle and secondary school students exhibit poor understanding of genetics due to misconceptions and difficulties that hinder progression in conceptual understanding of major genetics concepts and phenomena across different grade levels. They attributed these problems to Lebanon’s ill-structured genetics curriculum which needs a thorough revision in light of curricular reform models that take into account student misconceptions, cognitive abilities, and past experiences. Despite these claims, no empirical tests were done. Consequently, this study aimed to investigate G7-12 Lebanese students’ misconceptions and difficulties in genetics in an attempt to design a curriculum that would enhance student understanding of genetics. Using quantitative and qualitative data collection methods, we obtained an in-depth understanding of the nature of the misconceptions and difficulties encountered by students in grades 7–12, determined the level of students’ genetics literacy, and explored the progression of their level of conceptual understanding of major genetics concepts across grade levels. A questionnaire was administered to 729 students (G7-12) in 6 schools and was followed by semi-structured interviews with 62 students to validate the questionnaire results, gain further understanding of students’ misconceptions, and assess their level of genetics literacy. Findings showed that patterns of inheritance, the deterministic nature of genes, and the nature of genetic information were found to be among the most difficult concepts learned. Students also showed inadequate understanding of many basic genetics concepts which persist across grade levels. Furthermore, results indicated that students across all grade levels exhibited a low level of genetics literacy. Implications for practice and research are discussed.  相似文献   

5.
This study conducted at a suburban community college tested a method of conceptual change in which treatment students worked in small cooperative groups on tasks aimed at eliciting their misconceptions so that they could then be discussed in contrast to the scientific conceptions that had been taught in direct instruction. Categorizations of student understanding of the target concepts of the laws of conservation of matter and energy and aspects of the particulate nature of gases, liquids, and solids were ascertained by pre- and posttesting. Audiotapes of student verbal interaction in the small groups provided quantitative and qualitative data concerning student engagement in behaviors suggestive of the conditions posited to be part of the conceptual change process (Posner, Strike, Hewson & Gertzog, 1982). Chi-square analysis of posttests indicated that students in treatment groups had significantly lower (p < 0.05) proportion of misconceptions than control students on four of the five target concepts. Students who exhibited no change in concept state had a higher frequency of verbal behaviors suggestive of “impeding” conceptual change when compared to students who did change. Three factors emerged from qualitative analysis of group interaction that appeared to influence learning: (a) many students had flawed understanding of concepts that supported the target concepts; (b) student views towards learning science affected their engagement in assigned tasks, (c) “good” and “poor” group leaders had a strong influence on group success.  相似文献   

6.
  相似文献   

7.
An understanding of the concepts of atom and molecule is fundamental to the learning of chemistry. Any misconceptions and alternative conceptions that students harbor about these concepts will impede further learning. This article identifies misconceptions related to the fundamental characteristics of atoms and molecules which Grade-12 students hold. Data were obtained by administration of semistructured interviews to a stratified, random sample of 30 students of differing abilities and backgrounds in science. Fifty-two misconceptions were observed and are reported. These are grouped into 11 categories. Six relate to the structure, composition, size, shape, weight, bonding, and energy of molecules; five relate to the structure, shape, size, weight, and animistic perceptions of atoms. Some of the misconceptions identified parallel the historical development of scientific concepts.  相似文献   

8.
  相似文献   

9.
The study of magnets is a common physical science topic for elementary students. This study examined elementary science methods textbooks to determine how magnet concepts were presented. Each methods textbook's section relating to magnets was read. Particular attention was paid to the organization, sequence of concepts, potential misconceptions, and types of investigations included. A previously validated magnet concept list was used. A detailed analysis of 11 elementary science methods textbooks found great variation in the magnet concepts presented, general omission of ceramic magnets, frequent misconceptions about poles, and limited investigations that address both attraction and repulsion.  相似文献   

10.
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   

11.
The purpose of this study was to identify misconceptions concerning chemical equilibrium concepts and to investigate the effectiveness of instruction based on the constructivist approach over traditional instruction on 10th grade students' understanding of chemical equilibrium concepts. The subjects of this study consisted of 71 10th grade students from two chemistry classes of the same teacher. Each teaching strategy was randomly assigned to one class. The data were obtained from 32 students in the experimental group taught with instruction informed by the constructivist approach and 39 students in the control group taught with traditional instruction. The data were analysed using analysis of covariance. The results indicated that the students who used the constructivist principles-oriented instruction earned significantly higher scores than those taught by traditional instruction in terms of achievement related to chemical equilibrium concepts. In addition, students' previous learning and science process skills each made a significant contribution to the achievement related to chemical equilibrium concepts. In light of the findings obtained from the results, an additional misconception of chemical equilibrium concepts was determined in addition to the misconceptions in related literature. This misconception is that when one of the reactants is added to the equilibrium system, the concentration of the substance that was added will decrease below its value at the initial equilibrium.  相似文献   

12.
Educational researchers and teachers are well aware that misconceptions—erroneous ideas that differ from the scientifically accepted ones—are very common amongst students. Daily experiences, creative and perceptive thinking and science textbooks give rise to students' misconceptions which lead them to draw erroneous conclusions that become strongly attached to their views and somehow affect subsequent learning. The main scope of this study was to understand what students consider a mineral to be and why. Therefore, the goals were (1) to identify eleventh-grade students' misconceptions about the mineral concept; (2) to understand which variables (gender, parents' education level and attitude towards science) influenced students' conceptions; and (3) to create teaching tools for the prevention of misconceptions. In order to achieve these goals, a diagnostic instrument (DI), constituted of a two-tier diagnostic test and a Science Attitude Questionnaire, was developed to be used with a sample of 89 twelfth-grade students from five schools located in central Portugal. As far as we know, this is the first DI developed for the analysis of misconceptions about the mineral concept. Data analysis allows us to conclude that students had serious difficulties in understanding the mineral concept, having easily formed misconceptions. The variables gender and parents' education level influence certain students' conceptions. This study provides a valuable basis for reflection on teaching and learning strategies, especially on this particular theme.  相似文献   

13.
The aim of this study is to investigate the effectiveness of conceptual change oriented instruction (CCOI) over traditionally designed chemistry instruction (TDCI) on overcoming 10th grade students’ misconceptions on gases concepts. In addition, the effect of gender difference on students’ understanding of gases concepts was investigated. The subjects of this study consisted of 74 10th grade students from two chemistry classes. One of the classes was assigned as experimental group and the other group was assigned as control group. The experimental group was instructed with CCOI and the control group was instructed by TDCI. Gases Concept Test (GCT) was administered to both groups as pre- and post-tests to measure the students’ conceptual understanding. The results showed that students in the experimental group got higher average scores from Gases Concept Test. Also, a significant difference was found between the performance of females and that of males in terms of understanding gases concepts in favor of males.  相似文献   

14.
Abstract

We present ideas about concepts underlying climate change, held by students in years 9 and 10. Misconceptions about climate change are common among students, and may be due to misconceptions about underlying concepts. To investigate this, we developed the Climate Change Concept Inventory (CCCI), and trialed it with 229 students; corroborating findings through focus group interviews. Our interview method and data analysis methods are described. Findings included overestimation of human contributions to atmospheric carbon inputs, ultra violet radiation in sunlight, and greenhouse gases in the atmosphere. Students were unaware that CO2 dissolves in water, and of the role of oceans in the carbon cycle. Greenhouse gases other than CO2 were rarely known. Earth’s energy balance and black body radiation were not well understood. There were misconceptions about interactions between electromagnetic radiation and atmospheric gases; and limited understanding of carbon chemistry. The CCCI is available from the corresponding author.  相似文献   

15.
This research investigated students' understanding of electrochemistry following a 7–9-week course of instruction. A list of conceptual and propositional knowledge statements was formulated, and this provided the framework for semistructured interviews that were conducted with 32 students in their final year of high school chemistry, following instruction in electrochemistry. Three misconceptions identified in this study and five which have been reported earlier are incorporated into an alternative framework about electric current. The framework is grounded on the notion that a current always involves drifting electrons, even in solution. Another area where students' misconceptions were prevalent was in relation to the sign of the anode and cathode. Students who thought the anode was negatively charged believed cations would move toward it, and those who thought it was positively charged were unable to explain why electrons move away from it. Electrolytic cells also proved troublesome for students. Many students did not associate the positions of the anode and cathode with the polarity of the applied electromotive force (e.m.f.). Other students attempted to reverse features of electrochemical cells and apply the reversals to electrolytic cells. The implications of the research relate to students' interpretation of the language that is used to describe scientific phenomena and the tendency for students to overgeneralize, due to comments made by teachers or statements in textbooks.  相似文献   

16.
Understanding genetic drift is crucial for a comprehensive understanding of biology, yet it is difficult to learn because it combines the conceptual challenges of both evolution and randomness. To help assess strategies for teaching genetic drift, we have developed and evaluated the Genetic Drift Inventory (GeDI), a concept inventory that measures upper-division students’ understanding of this concept. We used an iterative approach that included extensive interviews and field tests involving 1723 students across five different undergraduate campuses. The GeDI consists of 22 agree–disagree statements that assess four key concepts and six misconceptions. Student scores ranged from 4/22 to 22/22. Statements ranged in mean difficulty from 0.29 to 0.80 and in discrimination from 0.09 to 0.46. The internal consistency, as measured with Cronbach''s alpha, ranged from 0.58 to 0.88 across five iterations. Test–retest analysis resulted in a coefficient of stability of 0.82. The true–false format means that the GeDI can test how well students grasp key concepts central to understanding genetic drift, while simultaneously testing for the presence of misconceptions that indicate an incomplete understanding of genetic drift. The insights gained from this testing will, over time, allow us to improve instruction about this key component of evolution.  相似文献   

17.
《Instructional Science》2012,40(5):745-754
Medical students often have initial understanding concerning medical domains, such as the central cardiovascular system (CCVS), when they enter the study programme. These notions may to some extent be in conflict with scientific understanding, which can be seen as a challenge for medical teaching. Hence, the purpose of this study was to analyse what kind of initial mental models students have about the CCVS and how these models change after a course. Further, we were interested in how medical students evaluate the role of problem-based learning (PBL)-enriched conventional instruction in their learning of the CCVS. Pre- and posttests consisting of a drawing task were conducted with 60 Finnish medical students. Additionally, problem-based learning and course evaluation questionnaires were administered. Results show that one-third of the students had misconceptions such as single-loop concepts in understanding the CCVS before the course. Although the instruction seems to support conceptual change, 10 % of the students did not reach a scientific model. In their evaluations of the learning environment, the students appreciated working in small groups in addition to lectures. Sixty-five percent of the students considered PBL an effective learning method, whereas the rest of the students found it ineffective. In sum, although most of the first-year medical students reached an adequate representation of the central cardiovascular system, too many seem to have resistant misconceptions. Hence, in developing learning environments that support students’ conceptual change in the medical domain, students’ prior knowledge and perceptions of learning environments need to be taken into account.  相似文献   

18.
The first of 3 objectives in this study was to address the major problem with Null Hypothesis Significance Testing (NHST) and 2 common misconceptions related to NHST that cause confusion for students and researchers. The misconceptions are (a) a smaller p indicates a stronger relationship and (b) statistical significance indicates practical importance. The second objective was to determine how this problem and the misconceptions were treated in 12 recent textbooks used in education research methods and statistics classes. The third objective was to examine how the textbooks' presentations relate to current best practices and how much help they provide for students. The results show that almost all of the textbooks fail to acknowledge that there is controversy surrounding NHST. Most of the textbooks dealt, at least minimally, with the alleged misconceptions of interest, but they provided relatively little help for students.  相似文献   

19.
  相似文献   

20.
Scientific research exploring ocean acidification has grown significantly in past decades. However, little science education research has investigated the extent to which undergraduate science students understand this topic. Of all undergraduate students, one might predict science students to be best able to understand ocean acidification. What conceptions and misconceptions of ocean acidification do these students hold? How does their awareness and knowledge compare across disciplines? Undergraduate biology, chemistry/biochemistry, and environmental studies students, and science faculty for comparison, were assessed on their awareness and understanding. Results revealed low awareness and understanding of ocean acidification among students compared with faculty. Compared with biology or chemistry/biochemistry students, more environmental studies students demonstrated awareness of ocean acidification and identified the key role of carbon dioxide. Novel misconceptions were also identified. These findings raise the question of whether undergraduate science students are prepared to navigate socioenvironmental issues such as ocean acidification.  相似文献   

设为首页 | 免责声明 | 关于勤云 | 加入收藏

Copyright©北京勤云科技发展有限公司  京ICP备09084417号