1,720,996 research outputs found
Chemical representational competences : a qualitative study on Hong Kong secondary student learning of covalent bonding, structures and properties
No full textChemical representational competencies (CRC) are fundamental competencies in chemistry. Extensive studies have discussed the significance of representational competencies in science, particularly in chemistry, and proposed various strategies or tools to enhance different aspects of CRC. However, students’ abilities and the difficulties that they may encounter in dealing with various chemical representations in learning chemistry are yet to be fully explored.
Firstly, this thesis introduces three models of representational competencies, namely, metavisualisation, metarepresentational competence and representational competence. Based on the curriculum requirement and textbook analyses of the structures and properties of covalent substances in the Hong Kong senior secondary chemistry curriculum, five representational competencies are identified and selected from the three models of representational competencies to develop the CRC model. These dimensions are (a) recognising chemical representations, (b) translating chemical representations, (c) identifying the differences between chemical representations and the concepts that they represent, (d) applying chemical representations in solving problems and (e) learning new chemical representations. Then, based on the literature, levels for each dimension of CRC are developed and used to analyse students’ competencies and their difficulties. To investigate students’ CRC in depth, this small-scale qualitative study was conducted. Two CRC written instruments were designed and administrated to a class of students who took senior secondary chemistry in Hong Kong in February 2016. Six students were selected for an interview. They were asked to elaborate on their responses to the instruments. All of the verbal and written responses, drawings and gestures were recorded, transcribed and analysed according to each dimension of CRC and the levels within each dimension.
This study has two major findings. Firstly, five dimensions of CRC are indispensable to students’ learning of the structures and properties of covalent substances. They are independent competencies but are related in many ways. For example, the translation of chemical representations is inseparable from students’ understanding of the submicroscopic structures of covalent substances. Moreover, the translation of chemical representations is informed by recognising the provided representation and enhances students’ recognition of the provided representation. Secondly, the difficulties that students may encounter with their CRC are identified. For example, students’ ideas about colours as a representation of temperatures that they acquired from physics are observed to have a negative influence on their learning of electron density diagrams.
This study has both theoretical and practical implications and significance. Theoretically, this research discusses the five dimensions of CRC needed in the context of the topic of the structures and properties of covalent substances and provides a comprehensive understanding of different levels of students’ CRC. These findings enrich the theory of representational competencies in science and shed light on further research on representational competencies in other science subjects. This study reveals to teachers, textbook authors and curriculum developers that they should pay attention to the difficulties that students may encounter with their CRC. Finally, we should acknowledge that these five dimensions of CRC are discussed in the context of this topic only. Thus, further studies of CRC in other topics are needed.published_or_final_versionEducationDoctoralDoctor of Philosoph
Going Beyond Counting First Authors in Author Co-citation Analysis
Get PDFThe present study examines one of the fundamental aspects of author co-citation analysis (ACA) - the way co-citation
counts are defined. Co-citation counting provides the data on which all subsequent statistical analyses and mappings
are based, and we compare ACA results based on two different types of co-citation counting - the traditional type that
only counts the first one among a cited work's authors on the one hand and a non-traditional type that takes into
account the first 5 authors of a cited work on the other hand. Results indicate that the picture produced through this non-traditional author co-citation counting contains more coherent author groups and is therefore considerably clearer. However, this picture represents fewer specialties in the research field being studied than that produced through the traditional first-author co-citation counting when the same number of top-ranked authors is selected and analyzed. Reasons for these effects are discussed
Learning difficulties in practical work of physics
No full textPractical work is an integral aspect of science lessons and it makes science distinctive from other subjects taught in school. In many countries around the world, practical work occupies a central position in secondary school science teaching. Although many teachers firmly believe that practical work can help students gain scientific knowledge, there is inconclusive findings in research literature to support this belief. The present study investigates the possible underlying learning difficulties faced by students in the various kinds of practical work that is commonly conducted in the teaching of physics.
Grade 9 students studying junior physics and grade 10–12 students studying senior physics in a secondary school in Hong Kong in 2013-2017 were invited to participate in this study. Samples classes of physics lessons including practical work were video recorded. Following the lessons, some students were selected for semi-structured interviews. This study examined the effectiveness of practical work in learning physics through an examination of the class videos, the post-class interviews and other data sources, including homework, tests, examinations and class observations. The learning difficulties faced by the students were identified and categorised. In total, this study identified six types of learning difficulties. This study also identified the underlying causes of each of these categories of learning difficulties.
Based on the difficulties identified in the sample classes of the first cohort, the study presents teaching and learning strategies aimed at addressing the barriers. In total, this study suggests 17 improvement strategies for the various kinds of learning difficulties. These strategies were implemented in the second cohort and their effectiveness in improving the students’ knowledge learning were evaluated. Some practical tips for these improvement strategies have also been suggested based on an evaluation.
The results of this study provide critical guidance for teachers when planning to include practical work in their lessons, so as to avoid any potential learning difficulties and improve the students’ acquisition of physics knowledge.published_or_final_versionEducationDoctoralDoctor of Philosoph
Examining socioscientific issues in the media by applying nature of science knowledge and media literacy concepts
No full textCritical evaluation of socioscientific issues (SSI) in the media has been recognised as an important goal of scientific literacy due to its crucial role in supporting individuals’ socioscientific decision-making and life-long learning. Although the media provides abundant information on SSI, its reporting has a purpose, which affects individuals’ judgment of SSI. Individuals should understand media literacy (ML) concepts. They should also have knowledge of the nature of science (NOS), because it affects individuals’ selection, evaluation and interpretation of scientific information in SSI, and the ways they respond to SSI. Yet previous studies have reported that students lack NOS knowledge and ML concepts to examine SSI in the media. Some studies have investigated how individuals’ understanding of NOS and ML concepts informs their examinations of science media reports. However, they have tended to discuss the effects of NOS and ML concepts separately. Little is known about how students apply both NOS and ML concepts to examinations of SSI news articles.
This study was situated in a general education university course developed to promote students’ application of NOS and ML concepts to examinations of SSI media reports. It aimed to explore how an integrated NOS and ML curriculum could lead individuals to change their examinations of SSI in the media. Changes in the students’ comprehension, analyses and evaluations of SSI news articles and the factors contributing to such changes were examined. Eleven undergraduates (Year 1 to Year 4) from diverse academic backgrounds (science majors, non-science majors, and journalism majors and minors) participated in the study. They were asked to examine four SSI news articles and complete SSI news evaluation questionnaires before and after NOS and ML instruction. Follow-up interviews were arranged to probe the underlying reasons for the changes in their responses after the instruction.
The students showed significant improvement in their comprehension, analyses and evaluations of SSI news articles after NOS and ML instruction. A model was developed to show six types of integration of NOS and ML concepts with different degrees contributed to the students’ critical examinations of SSI news articles. Nineteen obstacles hindering the students’ examinations of SSI in the media, 11 factors contributing to their improved performances in examinations of SSI news articles and 21 learning stimuli effective in promoting their critical examinations of SSI media reports were revealed.
This study unveils the limitations of the existing curriculum. Moreover, it shows that applying NOS knowledge or ML concepts alone is inadequate to comprehensively examine SSI news reports. To critically evaluate SSI in the media, individuals must have an in-depth understanding of both NOS and ML concepts, so they can jointly apply the concepts and combine them with other knowledge and skills to examine SSI news reports holistically. An integrated instructional approach connecting NOS and ML concepts is an effective pedagogy to promote critical examinations of SSI news reports. The suggestions in this thesis offer concrete guidelines for future curricular development focused on promoting critical examinations of SSI in the media.published_or_final_versionEducationDoctoralDoctor of Philosoph
Nurturing argumentation skills on socioscientific issues : identifying effective subject-related components from students' perceptions
No full textStudents’ argumentation skills have been the emphasis of many studies in science education during the last decade. As scientific literacy has advocated an informed decision-making about socioscientific issues (SSI), students are expected to apply sophisticated argumentation skills in the negotiation and resolution of these issues. Yet several studies reported that students’ argumentation skills on SSI were generally weak. Although some existing research has investigated how to nurture students’ argumentation skills on SSI, little is known about students’ perceptions of effective learning elements within the school curriculum.
The present study therefore adopted a student perspective to examine underlying factors in the development of students’ argumentation on SSI in the Hong Kong senior secondary education system. Hong Kong has undergone an educational reform in which certain subjects (e.g., Liberal Studies and Science) have new learning emphasis incorporated that is related to argumentation skills on SSI. Hence, learning in these subjects, termed as subject-related components in the present study, and respective learning experiences were of concern for understanding how various subjects helped to nurture students’ argumentation skills on SSI based on students’ perceptions.
One hundred and twenty students from a local secondary school participated in the study. Their argumentation skills in Secondary 4 and 6 were compared with reference to two data sources: performances in the SSI questionnaire and the recommendation of subject teachers teaching them argumentation skills and/or SSI. Students exhibiting an improvement in argumentation skills were invited for a group discussion about topics identical to those on the SSI questionnaire. Their argumentation skills in the group discussion were further analyzed and compared. The top nine students with the most sophisticated argumentation skills on SSI were invited for an individual interview to probe the subject-related components and respective learning experiences that facilitated their improvement in the skills.
Five subject-related components were identified: (i) framework of argumentation, (ii) apprehension of news reports, (iii) taking multiple perspectives, (iv) evidence understanding and (v) skepticism. These components – perceived by the students as interrelated – were brought about by various learning experiences such as issue-based writing tasks and scientific investigation. In addition, three major characteristics of acquiring the components were interpreted. First, synergy between subjects took place, in which different subjects were responsible for specific components and a nexus of subject learning was conducive to the development of argumentation skills. Second, various features of the learning experience, including being mark-oriented, open-ended and inquiry-based, helped facilitate the acquisition of the components. Third, relevant knowledge, skills as well as attitudes were cultivated to comprehensively support students’ argumentation skills on SSI.
Implications for nurturing students’ argumentation skills on SSI within the school curriculum were discerned, in particular the need for (i) the development of relevant knowledge, skills as well as attitudes through teaching the five subject-related components, and (ii) more research on student learning of argumentation skills on SSI from their own perspectives. The findings provide a better understanding of students’ authentic learning experience in the classroom and can help develop a more holistic model of student learning of argumentation skills on SSI.published_or_final_versionEducationDoctoralDoctor of Philosoph
Variations on the Author
Get PDF“Variations on the Author” discusses two of Eduardo Coutinho’s recent films (Um Dia na Vida, from 2010, and Últimas Conversas, posthumously released in 2015) and their contribution to the general question of documentary authorship. The director’s filmography is characterized by a consistent yet self-effacing form of authorial self-inscription: Coutinho often features as an interviewer that rather than express opinions propels discourses; an interviewer that is good at listening. This mode of self-inscription characterizes him as an author who is not expressive but who is nonetheless markedly present on the screen. In Um Dia na Vida, however, Coutinho is completely absent form the image, while Últimas Conversas, on the contrary, includes a confessional prologue that moves the director from the margins to the center of his films. This article examines the ways in which these works stand out in the filmography of a director who offers new insights into the notion of cinematic authorship
Appropriate Similarity Measures for Author Cocitation Analysis
Get PDFWe provide a number of new insights into the methodological discussion about author cocitation analysis. We first argue that the use of the Pearson correlation for measuring the similarity between authors’ cocitation profiles is not very satisfactory. We then discuss what kind of similarity measures may be used as an alternative to the Pearson correlation. We consider three similarity measures in particular. One is the well-known cosine. The other two similarity measures have not been used before in the bibliometric literature. Finally, we show by means of an example that our findings have a high practical relevance.information science;Pearson correlation;cosine;similarity measure;author cocitation analysis
Dispelling the Myths Behind First-author Citation Counts
Get PDFWe conducted a full-scale evaluative citation analysis study of scholars in the XML research field to explore just how different from each other author rankings resulting from different citation counting methods actually are, and to demonstrate the capability of emerging data and tools on the Web in supporting more realistic citation counting methods. Our results contest some common arguments for the continued
use of first-author citation counts in the evaluation of scholars, such as high correlations between author rankings by first-author citation counts and other citation
counting methods, and high costs of using more realistic citation counting methods that are not well-supported by the ISI databases. It is argued that increasingly available digital full text research papers make it possible for citation analysis studies to go beyond what the ISI databases have directly supported and to employ more
sophisticated methods
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