• Journal of the Korean Chemical Society
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• v.56 no.6
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• pp.739-750
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• 2012

The purpose of this study is to analyze the cognitive demands level of the description about 'pure substance and mixture compound', 'ionic compound', 'molecule' on the 'science2' textbooks by the 2007 revised curriculum. The three types of Curriculum Analysis Taxonomy have been used to analyze the cognitive demands level of those contents on the 6 kinds of 'science2' textbooks. The first, the cognitive demand level about 'pure substance and mixture compound' on many textbooks is a late concrete operational stage because of class inclusion and hierarchical classification. And the descriptions as 'pure substance is conserved even when mixed with other pure substance' is a early formal operational stage. The second, the cognitive demand level about 'ionic compound' and 'molecule' is a early formal operational stage, because of "Formal modeling is the indirect interpretation of reality by deductive comparison from a postulated system with its own rules" and "Atoms have a structure". The third, the terms as 'ionic bonding', 'ionic compound', 'chemical formula', 'covalent bonding', 'covalent compound', and 'molecular formula' have been used on many 'science2' textbooks. Those terms would be used later on 'chemistry I' and 'chemistry II' in senior high school but not even 'science3' and 'science'.

• Journal of The Korean Association For Science Education
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• v.26 no.7
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• pp.805-812
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• 2006

In this study the description patterns of chemistry textbooks on the boiling point elevation phenomenon and the understanding patterns of high school students, pre-service teachers and chemistry teachers were investigated. High school chemistry II textbooks developed in the 6th and 7th national curricula were analyzed and the conception patterns of subjects on this phenomenon were categorized using a questionnaire developed for this study. The description patterns of science textbooks were classified into three: 'decreasing of surface solvent molecules', 'attraction force between solvent and solute molecules' and 'decreasing of surface solvent molecules and attraction force between solvent and solute molecules'. In the result of the conception analysis, the ratio of 'attraction force between solvent and solute molecules' was high among students, pre-service teachers, and chemistry teachers. There was a propensity that they would like to explain the boiling point elevation in terms of enthalpy rather than entropy, and in order to analyze this propensity, follow-up interviews were carried out.

• Journal of Science Education
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• v.40 no.3
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• pp.254-266
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• 2016

In this study, MBL experiments in the Korean secondary science textbooks and chemistry textbooks under the 2007 and the 2009 curriculum revision were analyzed in terms of curriculum revision era, grade, context of experiment in the textbook, field of science, topic, sensor, and publisher. As a result, 25 MBL experiments were found in the science textbooks under the 2007 revision, and 29 experiments under the 2009 revision (19 for middle school textbook and 10 for high school textbook). MBL experiments in middle school textbooks were not increased after curriculum revision while those in high school textbooks appeared for the first time. Most of them were in the textbooks for grade 7 and presented as an essential experiment rather than optional one. Motion sensor and temperature sensor were used most frequently, and oxygen sensor and carbon dioxide sensor were followed. In aspect of publishers, a frequency of MBL experiment was decreased in most textbook and some publishers didn't include MBL experiment at all. Based on these results, educational implications were discussed.

• Journal of the Korean Chemical Society
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• v.48 no.6
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• pp.645-653
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• 2004

The purpose of this study was to compare and analyze the cognitive levels of 11th grade students and those required in high school chemistry I textbooks standardized by the 7th national education curriculum. For this study, the cognitive development stages of 456 11th grade students were surveyed using short-version GALT (group assessment of logical thinking). Furthermore, 15 basic concepts were extracted from the contents on water and air, 2 units in chemistry I order to analyze the cognitive levels necessary for understanding high school textbooks, using CAT (curriculum analysis taxonomy). The results showed that 52.5% of the surveyed 11th grade students reached the formal operational level, 28.3% transitional levels, and 19.5% concrete operational levels. 68.9% of the academic high school students and 6.6% of the technical high school students reached the formal operational levels, and the ratio of formation was very different in each logics. As a result of the analyzing the cognitive levels needed for understanding chemistry I textbook contents, in spite of a change in national education curriculum, there were no great change in cognitive levels required by scientific concept except some inquiry activities. The cognitive levels in high school chemistry I textbooks by the 7th national education curriculum appeared higher than the cognitive levels of 11th grade student, but cognitive levels of inquiry activities were similar to the cognitive levels of the students. Chemistry teachers thought of chemistry I textbooks by the 7th national education curriculum as desirable because scientific concepts were reduced and a lot of real life materials were adapted. However, they pointed out a problem of difference in contents levels compared with chemistry I textbooks because scientific concepts were greatly reduced in chemistry I textbooks. The cognitive levels required in chemistry I textbooks still appeared higher than those of the students. Consequently, various teaching and learning methods and materials will have to be developed to be suitable for the students' cognitive levels.

• The Journal of the Korea Contents Association
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• v.10 no.5
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• pp.427-435
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• 2010

We extracted core terms by constructing scientific item networks from textbooks, analyzing their structures, and investigating the connected information and their relationships. For this research, we chose three high-school textbooks from different publishers for each three subjects, i.e, Science, Biology I and Biology II, to construct networks by linking scientific items in each sentence, where used items were regarded as nodes. Scientific item networks from all textbooks showed scare-free character. When core networks were established by applying k-core algorithm which is one of generally used methods for removing lesser weighted nodes and links from complex network, they showed the modular structure. Science textbooks formed four main modules of physics, chemistry, biology and earth science, while Biology I and Biology II textbooks revealed core networks composed of more detailed specific items in each field. These findings demonstrate the structural characteristics of networks in textbooks, and suggest core scientific items helpful for students' understanding of concept in Science and Biology.

• Journal of The Korean Association For Science Education
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• v.27 no.4
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• pp.318-327
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• 2007

The purpose of this study is to examine the effects of small-scale chemistry(SSC) laboratory activities implemented in high school chemistry II classes on the students' inquiry process skills and science-related attitudes. For this study, 112 students in the 12th grade were chosen and divided into an experimental and a control group. Seven SSC lab programs that can replace the traditional experiments in chemistry II textbooks were selected and administered to the experimental group while the traditional textbook experiments were administered to the control group. The results showed that there was a significant difference in the enhancement of inquiry process skills between the two groups while no significant difference was found in science-related attitudes. Further analysis showed that the difference in the inquiry process skills came from the basic inquiry process skills. The experimental group students thought that the SSC experiments have many advantages compared to the traditional experiments, e.g., individual work, learning lab and theory in parallel, short experiment time, safety, environmental aspects, etc. These results suggest that the SSC lab programs are valuable in high school chemistry classes and developing and distributing various SSC lab programs is needed to replace the traditional experiments in the current textbooks.

• Journal of The Korean Association For Science Education
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• v.25 no.2
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• pp.88-97
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• 2005

The purpose of this study was to investigate explanations of science textbooks and science teachers' conceptions related to freezing point depression phenomenon. Seven kinds of middle school science textbooks and five kinds of high school chemistryII textbooks were analyzed for the purpose. The teachers' conceptions were searched by a questionnaire developed in this study. The subjects were 146 science teachers. The explanation types of science textbooks were divided into two; 'Description of the phenomenon' and 'Vapor pressure lowering'. The explanations in most of middle school science textbooks and high school chemistryII textbooks belong to 'Description of the phenomenon' and there was no explanation of the reason. The graphs related to depression of freezing point were diverse, too. Most of the science teachers also did not have scientific conception. The percentage of the teachers who thought that the cause of freezing point depression was blocking of solute in solution was high. But the teacher could not find meaningful relation the 'Blocking of solute' explanation represented for elevation of boiling point with depression of freezing point. It is insisted that entropy concept is need to explain depression of freezing point phenomenon in this study.

• Journal of the Korean Chemical Society
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• v.47 no.1
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• pp.79-86
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• 2003

Misconceptions of students for a Voltaic cell were studied and their contents described in the high school chemistry II textbooks were analyzed. This study shows that students have many misconceptions and a few of chemistry textbooks contain some false description in a Voltaic cell. In the most textbooks, the reasons why the measured cell voltage of a Voltaic cell is near 1.1 V at the initial stage and then it decreases with time are not explained clearly. The emf of a Voltaic cell at a standard state is 0.76 V but in some textbooks it is described as 1.1 V of a Daniel cell. Even after learning the Voltaic cell or performing the experiment of textbooks, most students still have some misconceptions. These may be due to at least two following facts: the first is that the measured cell voltage of a Voltaic cell at the initial stage is very similar to that of a Daniel cell. The second is that the most experiment of a Voltaic cell is not performed under the condition of a standard state. Therefore, we have suggested a model of the modified experimental setup of a Voltaic cell that could reduce misconceptions of students.

• Journal of the Korean Chemical Society
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• v.58 no.1
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• pp.126-129
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• 2014

Concerning the difficulty of learning science and reduced interest in science, the authors of this study searched for potential threshold concepts which are portals or gateways in the field of science (particularly chemistry). The nature of these concepts and how to overcome their troublesomeness were further questioned. For this study, 239 high school students completed chemistry II provided information about what difficult concepts and potential threshold concepts in high school chemistry are and how they affect learning chemistry. In particular, the mastery experience of the threshold concepts was explored in detail. Two, "mole and atomic structure" were selected as threshold concepts in chemistry. Not only as important but also as threshold, this study emphasized the importance of the two concepts in terms of features characterizing them as threshold concepts. In particular, the features objectify subjective experiences of students and provide information describing the scientific meaning and distinctive nature of threshold concepts in science. Along with the data from teachers, this study shows the integrative feature as key criteria for students to make meaningful understanding of the two threshold concepts.

• Journal of The Korean Association For Science Education
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• v.24 no.3
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• pp.544-555
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• 2004

This study examined the conception types of high school students, chemistry teachers, and pre-service teachers about the salt bridge in Daniel cell by a questionnaire and follow-up interviews. High school chemistry II textbooks were analyzed for finding the cause of the understanding difficulties of the teachers and students. Pre-service teachers' thoughts examined for the problems of pre-service teacher programs. From the analysis, it was found that teachers only thought that the role of salt bridge is for ion movement of two solutions involving electrodes. But they didn't have the conception that salt bridge has a roll of connection a circuit. This result was similar to students' and pre-service teachers' results. It was possible that insufficient and different explanations of the textbooks were attributed the teachers' and students' conceptual difficulties.