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1.
The need for renewable and non-fossil fuels is now recognised by nations throughout the world. Consequently, an understanding of alternative energy is needed both in schools and in everyday life-long learning situations. This study developed a two-tier instrument to diagnose students' understanding and alternative conceptions about alternative energy in terms of: sources of alternative energy, greenhouse gas emission, as well as advantages, and disadvantages. Results obtained with Years 10 and 11 students (n?=?491) using the 12-item two-tier instrument (α?=?0.61) showed that students' understanding of alternative energy was low (M?=?7.03; SD?=?3.90). The 23 alternative conceptions about alternative energy sources that could be identified from the instrument are reported. The implications for teaching and learning about alternative energy and suggestions for further development and improvement of the instrument are presented.  相似文献   

2.
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   

3.
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   

4.
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   

5.
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   

6.
The aim of the study was to discover the essential characteristics of engineering teachers' pedagogical content knowledge by studying teachers' conceptions of their students' ideas of moment. To compare the conceptions maintained by teachers with those of their students, the most common difficulties experienced by first-year engineering students in understanding the moments of forces were looked at. The data on students' conceptions were collected by means of a questionnaire. In addition, four experienced teachers were given the same questionnaire as the students and then were asked to write what they expected the students' answers to be. The students' answers and the teachers' conceptions of their students' potential answers were compared. It was found that although the teachers originally appeared to be familiar with their students' conceptions, they were rather astonished by the general pattern of the students' thinking. It is planned that the information gathered about the teachers' pedagogical content knowledge will eventually be used to improve engineering teacher training.  相似文献   

7.
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   

8.
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   

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.
11.
Natural selection as a mechanism of evolution is a central concept in biology; yet, most nonbiology‐majors do not thoroughly understand the theory even after instruction. Many alternative conceptions on this topic have been identified, indicating that the job of the instructor is a difficult one. This article presents a new diagnostic test to assess students' understanding of natural selection. The test items are based on actual scientific studies of natural selection, whereas previous tests have employed hypothetical situations that were often misleading or oversimplified. The Conceptual Inventory of Natural Selection (CINS) is a 20‐item multiple choice test that employs common alternative conceptions as distractors. An original 12‐item version of the test was field‐tested with 170 nonmajors in 6 classes and 43 biology majors in 1 class at 3 community colleges. The test scores of one subset of nonmajors (n = 7) were compared with the students' performances in semistructured interviews. There was a positive correlation between the test scores and the interview scores. The current 20‐item version of the CINS was field‐tested with 206 students in a nonmajors' general biology course. The face validity, internal validity, reliability, and readability of the CINS are discussed. Results indicate that the CINS will be a valuable tool for instructors. © 2002 Wiley Periodicals, Inc. J Res Sci Teach 39: 952–978, 2002  相似文献   

12.
This paper looks at the effect of instruction on pre-service science teachers' conceptions of the scientist. Twenty-six pre-service science teachers involved in a 14-week course were the subjects. The constructivist teaching approach was adopted. The students' preconceptions were the starting point for the teaching. Seven students were selected for in-depth interview to determine the reasons for their positions (change or no change in view at the end of the period). It was found that instruction enhanced better conceptions of the scientist. The pre-test to post-test change scores differed from zero and the difference was significant at the 0·05 level of significance. However, the interview revealed that the changes in conceptions were mediated by the students' life worldviews. We therefore conclude that whereas remediating strategies enhance understanding (comprehension), worldview of the students has a greater effect on meaningful learning (apprehension).  相似文献   

13.
Growing recognition of the central importance of fostering an in‐depth understanding of natural selection has, surprisingly, failed to stimulate work on the development and rigorous evaluation of instruments that measure knowledge of it. We used three different methodological tools, the Conceptual Inventory of Natural Selection (CINS), a modified version of Bishop and Anderson's (Bishop and Anderson [1990] Journal of Research in Science Teaching 27: 415–427) open‐response test that we call the Open Response Instrument (ORI), and an oral interview derived from both instruments, to measure biology majors' understanding of and alternative conceptions about natural selection. We explored how these instruments differentially inform science educators about the knowledge and alternative conceptions their students harbor. Overall, both the CINS and ORI provided excellent replacements for the time‐consuming process of oral interviews and produced comparable measures of key concept diversity and, to a lesser extent, key concept frequency. In contrast, the ORI and CINS produced significantly different measures of both alternative conception diversity and frequency, with the ORI results completely concordant with oral interview results. Our study indicated that revisions of both the CINS and ORI are necessary because of numerous instrument items characterized by low discriminability, high and/or overlapping difficulty, and mismatches with the sample. While our results revealed that both instruments are valid and generally reliable measures of knowledge and alternative conceptions about natural selection, a test combining particular components of both instruments—a modified version of the CINS to test for key concepts, and a modified version of the ORI to assess student alternative conceptions—should be used until a more approprite instrument is developed and rigorously evaluated. © 2008 Wiley Periodicals, Inc. J Res Sci Teach 45: 1131–1160, 2008  相似文献   

14.
This study investigated the conceptual understanding of measures of spread among community college students in an introductory statistics course. The course is centered around deemphasizing computational skills and focused, rather, on development of conceptual understanding. Open-ended questions were developed to explore and assess students' conceptual understanding of measures of spread. A detailed analysis of the students' responses is presented to reveal the range of students' conceptions of the measures of spread. The analysis of a wide variety of responses provides evidence of the students' ability to organize concepts of spread in a way that is meaningful to them individually. Some common student misconceptions revealed by this study should be examined closely and taken into consideration to promote students' development of understanding of spread.  相似文献   

15.
The potential influences of affective perceptions on cognitive engagement in learning, particularly with emotionally charged topics such as evolution, provide justification for acknowledging and assessing learners' attitudes toward content. One approach to determining students' attitudes toward a construct is to explicitly ask them to what degree they accept the related content. This was the approach we took as we developed the Inventory of Student Evolution Acceptance. Our goal was to make a finer-grained instrument that would assess acceptance on three evolution subscales: microevolution, macroevolution, and human evolution. Further, we sought to not conflate understanding with acceptance of the constructs. We began our instrument development with a series of interviews and open-ended questionnaires to determine students' perceptions of evolution acceptance. Based on the responses we developed and field tested a 49-item Likert scale instrument with stems distributed across our three targeted subscales. Using the data from our field test, we reduced the instrument to 24 items evenly distributed across the three subscales, and the revised instrument was again field tested with high school and undergraduate college students. The final instrument has an internal reliability of Cronbach's alpha of 0.96 and the items loaded onto three components that reflect documented evolution acceptance conditions. The instrument development, implications, and applications are discussed.  相似文献   

16.

The goal of this study was to understand how six college biology students complete the tasks of a traditional paper and pencil instrument designed to detect alternative conceptions about photosynthesis. Participants responded to relevant items in a two-tier diagnostic instrument in a think-aloud task. Responses to the traditional content question (first tier) were correct more often than reasons (second tier). However the participants' verbal data indicated that they relied upon test-taking strategies, not retrieval from memory, to choose their reasons. Some distractors caused participants to accept incorrect propositions being considered for the first time (rather than eliciting a misconception from extant knowledge). They also considered relevant exceptions and subtle language cues that justified their choices of incorrect reasons. Participants voiced concerns about the conscientiousness with which students complete such instruments. These findings raise concerns about the validity of using such instruments for diagnosing alternative conceptions.  相似文献   

17.
This study evaluates the use of an open‐ended question to determine students' knowledge structure on the topic of galvanic cells. The open‐ended question was developed and administered to 163 Grade 10 students who had earlier completed a course on electrochemistry. Students' responses were marked as well as coded on the basis of the fields identified from their responses. This was then evaluated statistically to determine the collective knowledge structure of the sample of students. The knowledge structure thus mapped contains both canonical concepts and alternative conceptions (ACs). An important finding emerging from this study is that instructors need to focus student's attention on the dynamic processes involving electrons and ions during the operation of galvanic cells. In order for students to fully understand how a galvanic cell operates, they need to see the whole picture. There are three critical components that lead to students' understanding of how an oxidation–reduction reaction can generate energy and how a circuit is complete: transfer of electrons during oxidation–reduction half‐reactions, flow of electrons within metals, and migration of ions in solution. Also, we found that it is possible for students to use correct chemistry concepts in an incorrect way by establishing linkages among these in an inappropriate manner. We reiterate that apart from evaluating students' ACs, it is also important to evaluate the links between the concepts and conceptions present in students' knowledge structure so that teaching can be made more effective.  相似文献   

18.
In this paper, we report a case study of a 16-year-old Swedish upper secondary student's developing understanding of key concept areas studied in his upper secondary school chemistry course. This study illustrates how the thinking of an individual learner, Jesper, evolves over a school year in response to formal instruction in a particular educational context. Jesper presented a range of ideas, some of which matched intended teaching whilst others were quite inconsistent with canonical chemistry. Of particular interest, research data suggest that his initial alternative conceptions influenced his thinking about subsequent teaching of chemistry subject matter, illustrating how students' alternative conceptions interact with formal instruction. Our findings support the claims of some researchers that alternative conceptions may be stable and tenacious in the context of instruction. Jesper's rich conceptualisation of matter at submicroscopic scales drew upon intuitions about the world that led to teaching being misinterpreted to develop further alternative conceptions. Yet his intuitive thinking also offered clear potential links with canonical scientific concepts that could have been harnessed to channel his developing thinking. These findings support the argument that identifying students' intuitive thinking and how it develops in different instructional contexts can support the development of more effective science pedagogy.  相似文献   

19.
This is a report on the investigation of a microcomputer-based system for the diagnosis and remediation of three Aristotelian alternative conceptions of force and motion held by eighth-grade physical science students. Diagnosis and posttesting were done with computer-displayed, graphics-based, multiple-choice questions. The two remediation simulations were designed to present scientific idealizations and to be perceived by the student as anomalous to the three alternative conceptions. Structured interviews were employed at several points during the study to obtain indications of the conceptions of force and motion of students with different achievement rankings, as well as to determine the students' reactions to the computer pretest questions or the simulations. A student's possession of alternative conceptions was unrelated to whether the student was a strong or weak learner of science. Students who were currently studying dynamics in their classes exhibited a very different pattern of nonscientific answers on the computer diagnostic test than did students who had completed that topic. The completed students who were selected for possession of alternative conceptions were facilitated by the computer simulations in altering their naive conceptions to a significant degree.  相似文献   

20.
The aim of this article was to study the reasons, strategies, and procedures that both students and teachers use to solve some chemical equilibrium questions and problems. Inappropriate conceptions on teaching and a lack of knowledge regarding the limited usefulness of Le Chatelier's principle, with its vague and ambiguous formulation and textbook presentation, may be some of the sources of misconceptions about the prediction of the effect of changing conditions on chemical equilibrium. To diagnose misconceptions and their possible sources, a written test was developed and administered to 170 1st-year university chemistry students. A chemical equilibrium problem, relating to the students' test, was solved by 40 chemistry teachers. First, we ascertained that teacher's conceptions might influence the problem-solving strategies of the learner. Based on this first aspect, our discussion also concerns students' and teachers' misconceptions related to the Le Chatelier's principle. Misconceptions emerged through: (a) misapplication and misunderstanding of Le Chatelier's principle; (b) use of rote-learning recall and algorithmic procedures; (c) incorrect control of the variables involved; (d) limited use of the chemical equilibrium law; (e) a lack of mastery of chemical equilibrium principles and difficulty in transferring such principles to new situations. To avoid chemical equilibrium misconceptions, a specific pattern of conceptual and methodological change may be considered.  相似文献   

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