The Nature of Scientific Explanation: Examining the perceptions of the nature,quality, and “goodness” of explanation among college students,science teachers,and scientists

Issues regarding scientific explanation have been of interest to philosophers from Pre-Socratic times. The notion of scientific explanation is of interest not only to philosophers, but also to science educators as is clearly evident in the emphasis given to K-12 students' construction of explanations in current national science education reform efforts. Nonetheless, there is a dearth of research on conceptualizing explanation in science education. Using a philosophically guided framework—the Nature of Scientific Explanation (NOSE) framework—the study aims to elucidate and compare college freshmen science students', secondary science teachers', and practicing scientists' scientific explanations and their views of scientific explanations. In particular, this study aims to: (1) analyze students', teachers', and scientists' scientific explanations; (2) explore the nuances about how freshman students, science teachers, and practicing scientists construct explanations; and (3) elucidate the criteria that participants use in analyzing scientific explanations. In two separate interviews, participants first constructed explanations of everyday scientific phenomena and then provided feedback on the explanations constructed by other participants. Major findings showed that, when analyzed using NOSE framework, participant scientists did significantly “better” than teachers and students. Our analysis revealed that scientists, teachers, and students share a lot of similarities in how they construct their explanations in science. However, they differ in some key dimensions. The present study highlighted the need articulated by many researchers in science education to understand additional aspects specific to scientific explanation. The present findings provide an initial analytical framework for examining students' and science teachers' scientific explanations.     

Representations of nature of science in high school chemistry textbooks over the past four decades

This study assessed the representations of nature of science (NOS) in high school chemistry textbooks and the extent to which these representations have changed during the past four decades. Analyses focused on the empirical, tentative, inferential, creative, theory‐driven, and social NOS, in addition to the myth of “The Scientific Method,” the nature of scientific theories and laws, and the social and cultural embeddedness of science. A total of 14 textbooks, including five “series” spanning one to four decades, were analyzed. The textbooks commanded significant market shares in the United States and were widely used in some of the most populace states. Relevant textbook sections were scored on each of the target NOS aspects on a scale ranging from −3 to +3, which reflected the accuracy, completeness, and manner (explicit versus implicit) in which these aspects were addressed. The textbooks fared poorly in their representations of NOS. Additionally, with a few exceptions, textbook scores either did not change or decreased over the past four decades. These trends are incommensurate with the discourse in national and international science education reform documents, which has witnessed an increasing emphasis on the centrality of NOS to scientific literacy and pre‐college science education during the same time period. Assessment and evaluation strategies, and policies need to be targeted if substantial and desired changes in the ways NOS is addressed in science textbooks are to be effected. © 2008 Wiley Periodicals, Inc. J Res Sci Teach 45: 835–855, 2008     

Interpretations of graphs by university biology students and practicing scientists: Toward a social practice view of scientific representation practices

Using graphs is a key social practice of professional science. As part of a research program that investigates the development of graphing practices from elementary school to professional science activities, this study was designed to investigate similarities and differences in graph‐related interpretations between scientists and college students engaged in collective graph interpretation. Forty‐five students in a second‐year university ecology course and four scientists participated in the study. Guided by domain‐ specific concerns, scientists' graph‐related activities were characterized by a large number of experience‐based, domain‐specific interpretive resources and practices. Students' group based activities were characterized by the lack of linguistic distinctions (between scientific terms) which led to ambiguities in group negotiations; there was also a lack of knowledge about specific organism populations which helped field ecologists construct meaning. Many students learned to provide correct answers to specific graphing questions but did not come to make linguistic distinctions or increase their knowledge of specific populations. In the absence of concerns other than to do well in the course, students did not appear to develop any general interpretive skills for graphs, but learned instead to apply the professor's interpretation. This is problematic because, as we have demonstrated, there are widely differing viable interpretations of the graph. Suggestions for changes in learning environments for graphing that should alleviate this problem are made. © 1999 John Wiley & Sons, Inc. J Res Sci Teach 36: 1020–1043, 1999     

From scientific practice to high school science classrooms: Transfer of scientific technologies and realizations of authentic inquiry

The Biology Workbench (BW) is a web‐based tool enabling scientists to search a wide array of protein and nucleic acid sequence databases with integrated access to a variety of analysis and modeling tools. The present study examined the development of this scientific tool and its consequent adoption into the context of high school science teaching in the form of the Biology Student Workbench (BSW). Participants included scientists, programmers, science educators, and science teachers who played key roles along the pathway of the design and development of BW, and/or the adaptation and implementation of BSW in high school science classrooms. Participants also included four teachers who, with their students, continue to use BSW. Data sources included interviews, classroom observations, and relevant artifacts. Contrary to what often is advocated as a major benefit accruing from the integration of authentic scientific tools into precollege science teaching, classroom enactments of BSW lacked elements of inquiry and were teacher‐centered with prescribed convergent activities. Students mostly were preoccupied with following instructions and a focus on science content. The desired and actual realizations of BSW fell on two extremes that reflected the disparity between scientists' and educators' views on science, inquiry science teaching, and the related roles of technological tools. Research on large‐scale adoptions of technological tools into precollege science classrooms needs to expand beyond its current focus on teacher knowledge, skills, beliefs, and practices to examine the role of the scientists, researchers, and teacher educators who often are involved in such adoptions. © 2010 Wiley Periodicals, Inc. J Res Sci Teach 48: 37–70, 2011     

Socio‐scientific controversies and students' conceptions about scientists

This article discusses the results of a mainly qualitative study into possible impacts of recent controversial socio‐scientific issues on a group of Portuguese secondary school students regarding their conceptions about scientists. The 86 participants: (1) answered a questionnaire with open‐ended questions; and (2) wrote a science fiction story involving a group of scientists working on a particular situation of her/his choice. Next, semi‐structured interviews were carried out to clarify and discuss the ideas embodied in the stories and mentioned in the questionnaire. All data underwent a process of content analysis. The socio‐scientific controversies recently discussed, and the way science and scientists are depicted in the media, seem to have produced some impact on students' conceptions about scientists. Based on the results obtained, some remarks and educational implications are discussed.     

Making sense of genetics: Students' knowledge use during problem solving in a high school genetics class

Interest in including ideas about the nature of science in instruction and research has led to the realization that, in addition to developing courses which offer students experience with science practice, it is important to understand the ways in which students learn and use science knowledge within such courses. The study reported here is based on a particular view of the nature of scientific practice: Science is collaborative; scientists use knowledge in the construction of new knowledge; and scientists' understanding of problems and problem-solving strategies change during knowledge construction. Given this perspective, the study examines the ways in which students in an innovative high school genetics class collaborate to construct knowledge as they develop genetics models. In this classroom, students use three kinds of knowledge: knowledge of genetics, permitting them to recognize anomalous aspects of new data and providing a template from which to develop new models; knowledge of the process of model revision, helping them make decisions about how to develop new models; and knowledge of their own problem-solving strategies, allowing them to “keep track” of what they have done, as well as make connections between the development of new models and their knowledge of genetics. © 1996 John Wiley & Sons, Inc.     

Adaptations and Continuities in the Use and Design of Visual Representations in US Middle School Science Textbooks

Visual representations are ubiquitous in modern‐day science textbooks and have in recent years become an object of criticism and scrutiny. This article examines the extent to which changes in representations in textbooks published in the USA over the past six decades have invited those critiques. Drawing from a correlational analysis of a corpus of 34 US middle school physical science textbooks, continuities are established with respect to the purposes that most textbook images serve and the numbers of schematic representations that are used. Changes are observed in the overall total number of representations in textbooks and in the proportion of representations that are photographic. Interpretive cases of individual representations over time are presented to further illustrate the continuities and changes that have taken place. Specifically, high‐fidelity images, such as photographs, are shown permeating or replacing schematic and explanatory images in the interest of promoting familiarization to students. This shifting emphasis toward familiarization is discussed as a specific cause for concern about quality and utility of representations in modern‐day US science textbooks.     

Understanding the Greenhouse Effect by Embodiment – Analysing and Using Students' and Scientists' Conceptual Resources

Over the last 20 years, science education studies have reported that there are very different understandings among students of science regarding the key aspects of climate change. We used the cognitive linguistic framework of experientialism to shed new light on this valuable pool of studies to identify the conceptual resources of understanding climate change. In our study, we interviewed 35 secondary school students on their understanding of the greenhouse effect and analysed the conceptions of climate scientists as drawn from textbooks and research reports. We analysed all data by metaphor analysis and qualitative content analysis to gain insight into students' and scientists' resources for understanding. In our analysis, we found that students and scientists refer to the same schemata to understand the greenhouse effect. We categorised their conceptions into three different principles the conceptions are based on: warming by more input, warming by less output, and warming by a new equilibrium. By interrelating students' and scientists' conceptions, we identified the students' learning demand: First, our students were afforded with experiences regarding the interactions of electromagnetic radiation and CO₂. Second, our students reflected about the experience-based schemata they use as source domains for metaphorical understanding of the greenhouse effect. By uncovering the—mostly unconscious—deployed schemata, we gave students access to their source domains. We implemented these teaching guidelines in interventions and evaluated them in teaching experiments to develop evidence-based and theory-guided learning activities on the greenhouse effect.     

A comparative study of three methods for the popularization of a physical phenomenon

A study of Norwegian science textbooks for grade 8 indicates an individualistic image of science where individual scientists are discovering truth, through experiment. Scientific rationality is grounded in procedures of inquiry alone and not in debate and argumentation within scientific communities. The communal aspects of science tend to become visible in historical examples where science did not function properly due to prejudices or ignorance. Furthermore, science proper and school science are not differentiated between, and 'scientific knowledge about nature' and 'nature' are one and the same. The discourse identified is well suited to provide students with broad and general knowledge about natural and everyday phenomena. However, it is less suitable for teaching about the scientific enterprise in contemporary society. This is worrying for students' scientific literacy as future adults, as this dimension is essential for understanding the nature of science and for democratic citizenship in socio-scientific issues.     

Portraying science in the classroom: The manifestation of scientists' beliefs in classroom practice

If the goals of science education reform are to be realized, science instruction must change across the academic spectrum, including at the collegiate level. This study examines the beliefs and teaching practices of three scientists as they designed and implemented an integrated science course for nonmajors that was designed to emphasize the nature of science. Our results indicated that, like public school teachers, scientists' beliefs about the nature of science are manifested in their enactment of curriculum—although this manifestation is clearly not a straightforward or simplistic one. Personal beliefs about the nature of science can differ from those of the course, thus resulting in an enactment that differs from original conceptions. Even when personal beliefs match those of the course, sophisticated understandings of the nature of science are not enough to ensure the straightforward translation of beliefs into practice. Mitigating factors included limited pedagogical content knowledge, difficulty in achieving integration of the scientific disciplines, and lack of opportunity and scaffolding to forge true consensus between the participating scientists. © 2003 Wiley Periodicals, Inc. J Res Sci Teach 40: 669–691, 2003     

Turning Crisis into Opportunity: Enhancing student‐teachers’ understanding of nature of science and scientific inquiry through a case study of the scientific research in severe acute respiratory syndrome

Interviews with key scientists involved in research on severe acute respiratory syndrome (SARS), together with analysis of media reports and documentaries produced during and after the SARS epidemic, revealed many interesting aspects of nature of science (NOS) and authentic scientific inquiry. This novel insight into practice in the rapidly growing field of molecular biology was used in the development of instructional materials for use in the pre‐service and in‐service teacher education programme at The University of Hong Kong. The elements of NOS and scientific inquiry identified in the scientific research on SARS were explicitly emphasized in our instructional materials. The contemporary real‐life context of SARS was found to be effective in promoting student‐teachers’ understanding of NOS and scientific inquiry, particularly in terms of: the realization of inseparable links between science and the social, cultural, and political environment; deeper understanding of how science and technology impact on each other; and a richer appreciation of the processes of authentic scientific inquiry and the humanistic character of scientists. The effectiveness is attributed to immediacy, relevance, and familiarity, making the abstract tangible, personal experience of science history, and the powerful affective impact of the interviews with scientists.     

Elementary students' views of explanation,argumentation, and evidence,and their abilities to construct arguments over the school year

Science includes more than just concepts and facts, but also encompasses scientific ways of thinking and reasoning. Students' cultural and linguistic backgrounds influence the knowledge they bring to the classroom, which impacts their degree of comfort with scientific practices. Consequently, the goal of this study was to investigate 5th grade students' views of explanation, argument, and evidence across three contexts—what scientists do, what happens in science classrooms, and what happens in everyday life. The study also focused on how students' abilities to engage in one practice, argumentation, changed over the school year. Multiple data sources were analyzed: pre‐ and post‐student interviews, videotapes of classroom instruction, and student writing. The results from the beginning of the school year suggest that students' views of explanation, argument, and evidence, varied across the three contexts with students most likely to respond “I don't know” when talking about their science classroom. Students had resources to draw from both in their everyday knowledge and knowledge of scientists, but were unclear how to use those resources in their science classroom. Students' understandings of explanation, argument, and evidence for scientists and for science class changed over the course of the school year, while their everyday meanings remained more constant. This suggests that instruction can support students in developing stronger understanding of these scientific practices, while still maintaining distinct understandings for their everyday lives. Finally, the students wrote stronger scientific arguments by the end of the school year in terms of the structure of an argument, though the accuracy, appropriateness, and sufficiency of the arguments varied depending on the specific learning or assessment task. This indicates that elementary students are able to write scientific arguments, yet they need support to apply this practice to new and more complex contexts and content areas. © 2011 Wiley Periodicals, Inc. J Res Sci Teach 48: 793–823, 2011     

Chemical understanding and graphing skills in an honors case‐based computerized chemistry laboratory environment: The value of bidirectional visual and textual representations

The case‐based computerized laboratory (CCL) is a chemistry learning environment that integrates computerized experiments with emphasis on scientific inquiry and comprehension of case studies. The research objective was to investigate chemical understanding and graphing skills of high school honors students via bidirectional visual and textual representations in the CCL learning environment. The research population of our 3‐year study consisted of 857 chemistry 12th grade honors students from a variety of high schools in Israel. Pre‐ and postcase‐based questionnaires were used to assess students' graphing and chemical understanding–retention skills. We found that students in the CCL learning environment significantly improved their graphing skills and chemical understanding–retention in the post‐ with respect to the prequestionnaires. Comparing the experimental students to their non‐CCL control peers has shown that CCL students had an advantage in graphing skills. The CCL contribution was most noticeable for experimental students of relatively low academic level who benefit the most from the combination of visual and textual representations. Our findings emphasize the educational value of combining the case‐based method with computerized laboratories for enhancing students' chemistry understanding and graphing skills, and for developing their ability to bidirectionally transfer between textual and visual representations. © 2008 Wiley Periodicals, Inc. J Res Sci Teach 45: 219–250, 2008.     

Scientists' views of science,models of writing,and science writing practices

Written and oral communications and the processes of writing and reading are highly valued within the scientific community; scientists who communicate well are successful in gaining recognition and support from members of their own communities, the research funding agencies, and the wider society. Yet how do scientists achieve this proficiency? Are expert scientists equally expert writers in and of science? Do scientists' perceptions of the nature of science influence their writing strategies and processes, and their beliefs about the role of writing in knowledge construction? This study used a questionnaire and semistructured interviews to document these perceptions, strategies, processes, and beliefs in a nonrandom sample of Canadian university scientists and engineers. The results indicate that the scientists subscribed to a contemporary evaluativist view of science, used common writing strategies, held similar beliefs about scientific writing and nonscientific writing, and agreed that writing generates insights and clarifies ambiguity in science. The engineers held a different view of technology than the common views of science or technology as simply applied science. These findings were slightly different than those found for American scientists from a large land‐grant university. © 2004 Wiley Periodicals, Inc. J Res Sci Teach 41: 338–369, 2004     

Relations among three aspects of first‐year college students' epistemologies of science

At the start of their first semester, 35 college freshmen were given an interview probing (a) their differentiation of scientists' ideas from evidence, and hypotheses from theories; (b) their understanding of the inherent uncertainty of scientific knowledge; and (c) their reasoning about scientific controversies. The most common responses were in terms of an epistemology in which scientists' ideas and evidence are differentiated, and theories are understood as tested hypotheses (Level 2 in our system based on Carey, Evans, Honda, Jay, & Unger, 1989), although students varied in how consistently they differentiated theories and evidence across all questions. Responses in which theories are understood as broader explanatory frameworks guiding hypothesis testing (Level 3) were virtually nonexistent, but some students gave responses that showed awareness of processes of interpreting and reinterpreting patterns of results (Level 2.5). Responses across the three parts of the interview were significantly related. Consistently differentiating scientists' ideas from evidence was strongly related to appreciating the inherent uncertainty of scientific knowledge and with having a deeper understanding of the reasons for scientific controversies and how to resolve them. © 2006 Wiley Periodicals, Inc. J Res Sci Teach 43: 747–785, 2006     

Gender ratios in high school science departments: The effect of percent female faculty on multiple dimensions of students' science identities

To examine how school characteristics are tied to science and engineering views and aspirations of students who are underrepresented in science and engineering fields, this mixed‐methods study explores relationships between aspects of students' science identities, and the representation of women among high school science teachers. Quantitative analyses tested the hypothesis that percent female faculty would have a positive effect on girls' science interests, and perceptions in particular, given the potentially greater availability of women role models. Findings indicate that percent female science faculty does not have an effect on a range of science measures for both male and female students, including the ways in which they understand scientific practice, their science self‐concept, and their interest in science‐related college majors. As qualitative data demonstrate, this could reflect practical constraints at schools where female faculty are concentrated and narrow perceptions of science teachers and “real” science. © 2007 Wiley Periodicals, Inc. J Res Sci Teach 44: 980–1009, 2007     

Camila,the earth,and the sun: Constructing an idea as shared intellectual property

Recent research has challenged traditional assumptions that scientific practice and knowledge are essentially individual accomplishments, highlighting instead the social nature of scientific practices, and the co‐construction of scientific knowledge. Similarly, new research paradigms for studying learning go beyond focusing on what is “in the head” of individual students, to study collective practices, distributed cognition, and emergent understandings of groups. These developments require new tools for assessing what it means to learn to “think like a scientist.” Toward this goal, the present case study analyzes the discourse of a 6th‐grade class discussing one student's explanation for seasonal variations in daylight hours. The analysis identifies discourse moves that map to disciplinary practices of the social construction of science knowledge, including (1) beginning an explanation by reviewing the community's shared assumptions; (2) referencing peers' work as warrants for an argument; and (3) building from isolated ideas, attributed to individuals, toward a coherent situation model, attributed to the community. The study then identifies discourse moves through which the proposed explanation was taken up and developed by the group, including (4) using multiple shared representations; (5) leveraging peers' language to clarify ideas; and (6) negotiating language and representations for new, shared explanations. Implications of this case for rethinking instruction, assessment, and classroom research are explored. © 2009 Wiley Periodicals, Inc. J Res Sci Teach 47:619–642, 2010     

从高校写作教材存在的问题反思其编写理念

就已出版的高校写作教材存在的诸多失误,分析其中的共同问题,提出教材编写的理念是：必须坚持马克思主义的观点和方法,要有以培养学生创新的写作能力为核心的意识和阐释适合于大学写作教材的科学理论的层次观念,找准写作学独有的研究对象,探索能够既揭示写作规律又符合教学规律的具有可操作性的写作理论体系。