The Oil Drop Experiment: A Rational Reconstruction of the Millikan–Ehrenhaft Controversy and Its Implications for Chemistry Textbooks

Research in science education has recognized the importance of history and philosophy of science. Given this perspective, it is important to analyze how general chemistry textbooks interpret Millikan's oil drop experiment. This study has the following objectives: (a) elaboration of a history and philosophy of science framework based on a rational reconstruction of experimental observations that led to the Millikan–Ehrenhaft controversy; (b) formulation of six criteria based on the framework, which could be useful in the evaluation of chemistry textbooks; and (c) evaluation of 31 chemistry textbooks based on the criteria. Results obtained showed that most textbooks lacked a history and philosophy of science framework and did not deal adequately with the following aspects. (a) The Millikan–Ehrenhaft controversy can open a new window for students, demonstrating how two well‐trained scientists can interpret the same set of data in two different ways. (b) Millikan's perseverance with his guiding assumption shows how scientists can overcome difficulties with anomalous data. (c) Millikan's methodology illustrates what modern philosophers of science consider important issues of falsification, confirmation, and suspension of disbelief. (d) The experiment is difficult to perform even today, owing to the incidence of a series of variables. (e) Millikan's major contribution consists of discovering the experiment to provide confirmation for the elementary electrical charge. © 2000 John Wiley & Sons, Inc. J Res Sci Teach, 37: 480–508, 2000.     

How in Spite of the Rhetoric,History of Chemistry has Been Ignored in Presenting Atomic Structure in Textbooks

Recent research in science education has recognized the importance of history and philosophy of science. This study has the following objectives:(a) To show how the importance of history of chemistry has been recognized in theclassroom, starting from the 1920s to the present; (b) How criteria based on history andphilosophy of science can be used to evaluate presentation of atomic structure in generalchemistry textbooks; (c) Comparison of the new (1970–1992) and old textbooks (1929–1967)with respect to the presentation of atomic structure. Results obtained show thatmost of the new and old textbooks not only ignore the history and philosophy of sciencebut also present experimental findings as a `rhetoric of conclusions'. It isconcluded that such presentations are not conducive towards a better understanding of scientificprogress. It is suggested that history and philosophy of science can be introduced in theclassroom not necessarily through formal courses in the history of chemistry or commentsand anecdotes, but rather by incorporating the `heuristic principles' that guided thescientists to elaborate their theories.     

The Oil Drop Experiment: An Illustration of Scientific Research Methodology and its Implications for Physics Textbooks

The objectives of this study are:(1) evaluation of the methodology used in recent search for particles with fractional electrical charge (quarks) and its implications for understanding the scientific research methodology of Millikan; (2) evaluation of 43 general physics textbooks and 11 laboratory manuals, with respect to the oil drop experiment, based on seven history and philosophy of science criteria. Results obtained show that all the textbooks and manuals ignored the Millikan–Ehrenhaft controversy and in general lacked a history and philosophy of science perspective. In spite of the anomalous data, Millikan adhered to the guiding assumptions of his research program. Ehrenhaft's work strictly followed the logic of experimental observations. Although, Ehrenhaft's work approximated the traditional scientific method, the scientific community supported Millikan. General physics textbooks and laboratory manuals present the oil drop experiment as an example of the scientific method in which experimental data implicitly serves as an arbiter in the defense of Millikan. It is suggested that textbooks and manuals by including the Millikan–Ehrenhaft controversy and the methodology used in the search for quarks could enrich students' understanding of scientific research methodology, viz., experimental data do not always dictate the choice of a theory.     

A Reconstruction of Structure of the Atom and Its Implications for General Physics Textbooks: A History and Philosophy of Science Perspective

Recent research in science education has recognized the importance of history and philosophy of science. The objective of this study is to evaluate the presentation of the Thomson, Rutherford, and Bohr models of the atom in general physics textbooks based on criteria derived from history and philosophy of science. Forty-one general physics textbooks (all published in the United States) were evaluated on two criteria based on Thomson's work, three on Rutherford's work, and three on Bohr's work. Results obtained show that general physics textbooks do not systematically include a history and philosophy of science perspective. Most textbooks present an inductivist perspective in which experimental details are considered to be paramount. On the contrary, a historical reconstruction of the experimental details inevitably includes: the context in which an experiment is conducted, the theoretical framework that guides the scientist, and alternative interpretations of data that lead to conflicts and controversies. Examples are provided to show how historical reconstructions of atomic models can provide students an opportunity to appreciate how scientists work and science progresses. It is plausible to suggest that textbook presentations based on a history and philosophy of science perspective can perhaps arouse students' interest in the subject and hence lead to greater conceptual understanding.     

Progressive transitions in chemistry teachers’ understanding of nature of science based on historical controversies

The objective of this study is to facilitate progressive transitions in chemistry teachers understanding of nature of science in the context of historical controversies. Selected controversies referred to episodes that form part of the chemistry curriculum both at secondary and university freshman level. The study is based on 17 in-service teachers who had registered for an 11-week course on ‘Investigation in the teaching of chemistry’ as part of their Master’s degree program. The course is based on 17 readings drawing on a history and philosophy of science perspective with special reference to controversial episodes in the chemistry curriculum. Course activities included written reports, class room discussions based on participants’ presentations, and written exams. Based on the results obtained it is suggested that this study facilitated the following progressive transitions in teachers’ understanding of nature of science: (a) Problematic nature of the scientific method, objectivity and the empirical basis of science; (b) Myths associated with respect to the nature of science and teaching chemistry; (c) Science does not develop by appealing to objectivity in an absolute sense, as creativity and presuppositions also play a crucial role; (d) The role of speculation and controversy in the construction of knowledge based on episodes from the chemistry curriculum; (e) How did Bohr confirm his postulates? This goes beyond the treatment in most textbooks; (f) Differentiation between the idealized scientific law and the observations. It is concluded that given the opportunity to reflect, discuss and participate in a series of course activities based on various controversial episodes, teachers’ understanding of nature of science can be enhanced.     

The Oil Drop Experiment: Do Physical Chemistry Textbooks Refer to its Controversial Nature?

Most general chemistry textbooks consider the oil drop experiment as a classic experiment, characterized by its simplicity and precise results. A review of the history and philosophy of science literature shows that the experiment is difficult to perform (even today!) and generated a considerable amount of controversy. Acceptance of the quantization of the elementary electrical charge was preceded by a bitter dispute between R.A. Millikan and F. Ehrenhaft, that lasted for many years (1910–1925). The objective of this study was to investigate whether physical chemistry textbooks refer to the controversial nature of the experiment. Based on six criteria developed previously, 28 physical chemistry textbooks were evaluated. Analysis of the texts using six identified criteria demonstrated that the textbooks neither referred to the controversial nature of the experiment nor recognized the difficulty of the experimental procedure. Only a few texts even attempted to include any discussion of the history or philosophy of the experiment. The instructor of a physical chemistry course could include aspects of the Millikan–Ehrenhaft controversy to motivate classroom discussion and help facilitate an understanding of the role that controversy has in scientific progress.     

A reconstruction of development of the periodic table based on history and philosophy of science and its implications for general chemistry textbooks

The objectives of this study are: (a) elaboration of a history and philosophy of science (HPS) framework based on a reconstruction of the development of the periodic table; (b) formulation of seven criteria based on the framework; and (c) evaluation of 57 freshman college‐level general chemistry textbooks with respect to the presentation of the periodic table. The historical reconstruction of the periodic table showed that the periodicity of the elements could be construed as an inductive generalization or as a function of the atomic theory. There is considerable controversy with respect to the nature of Mendeleev's contribution, and various alternatives are discussed: ordered domain; empirical law; and a theory with limited explanatory power. Accommodation of the elements according to their physicochemical properties is considered to be the major contribution of the periodic table by all textbooks, followed by contrapredictions of previously unknown elements (30 textbooks), and novel predictions (corrections of atomic mass) of known elements (10 textbooks). The relative importance of accommodation and prediction within an HPS framework is generally ignored. Few textbooks have attempted to explore the possible cause of periodicity in the table and very few textbooks have explored the nature of Mendeleev's contribution. The development of the periodic table as a sequence of heuristic principles in the form of a convincing argument has been ignored. The textbook approach of emphasizing that the development of the periodic table was an inductive generalization, and that Mendeleev had no model or theory, does not facilitate the spirit of critical inquiry that led the scientists to grapple with alternative interpretations, conflicts, and controversies. It is concluded that the development of the periodic table went through a continual critical appraisal (conflict and controversy), in which scientists presented various tentative theoretical ideas to understand the observed phenomena. © 2004 Wiley Periodicals, Inc. J Res Sci Teach 42: 84–111, 2005     

Gases as Idealized Lattices: A Rational Reconstruction of Students' Understanding of the Behavior of Gases

The main objective of this study is to establish a relationship between students' understanding of gases and its parallels in the history of science (rational reconstruction). Fifty-nine freshman students were asked to respond to a gas problem that did not require any calculations but rather conceptual understanding (due to molecular collisions, gases occupy all the available space). Before responding to the problem students were exposed to an elementary version of the kinetic theory of gases. Results obtained showed that a large proportion of the students gave explanations that approximate quite closely to an idealized form of the Lattice Theory of Gases. This theory considered molecules in gases to be arranged in the form of regular lattices, rather as if gases were highly expanded solids, and was held by most chemists until about 1860. It is concluded that some of the students' alternative conceptions about gas behavior (attractive forces between gas molecules increase as the temperature decreases) are resistant to change and recapitulate theories scientists held in the past.     

Using Story to Help Student Understanding of Gas Behavior

Students tend to have a poor understanding of the concept of gas pressure. Usually, gas pressure is taught in terms of the various formulaic gas laws. The development of the concept of gas pressure according to the early Greeks did not include the concept of a vacuum. It was not for another 2000 years that Torricelli proposed that a vacuum can exist and that he was able to produce a vacuum above a column of mercury. However, the existence of a vacuum continued to be a contentious issue for at least another 100 years. During this time the behavior of gases was studied by Boyle, Amontons, Gay-Lussac, Daniel Bernouli, Charles, and Dalton. In the 19^th century gas behavior was revisited and studied from the molecular level through the work of Graham, Maxwell, Boltzmann, and van der Waal. The stories of conflicting theories and the development of the concept of gas pressure gives students an increased appreciation for the nature of science and helps them with conceptual understanding of the concept of gas pressure.     

A rational reconstruction of the origin of the covalent bond and its implications for general chemistry textbooks

The main objectives of this study are: (i) development of a perspective based on history and philosophy of science considerations (rational reconstruction) in order to understand the postulation of the covalent bond by Lewis; (ii) formulation of four criteria based on the perspective; and (iii) evaluation of 27 textbooks based on the four criteria. Results obtained show that most textbooks lacked a history and philosophy of science perspective and did not deal adequately with the following aspects: (i) Lewis's postulation of the covalent bond in 1916 posed considerable conceptual difficulties; (ii) Lewis used the cubical atom (a hypothetical entity) in order to understand the sharing of electrons in the covalent bond (octet rule); (iii) sharing of electrons had to compete with the transfer of electrons (ionic bond) considered to be the dominant paradigm until about 1920; (iv) postulation of the covalent bond (octet rule) was not an inductive generalization based on stability of the noble gases and the high dissociation energy of the covalent bonds; and (v) Pauli exclusion principle provides a theoretical explanation of the sharing of electrons, just as the cubical atom did previously. It is concluded that the development of the covalent bond does not follow the inductivist process, viz. experimental observations lead to scientific laws which later facilitate the elaboration of explanatory theories.     

Quantitative Analysis of Representations of Nature of Science in Nordic Upper Secondary School Textbooks Using Framework of Analysis Based on Philosophy of Chemistry

The aim of this study was to assess how the different aspects of nature of science (NOS) were represented in Finnish and Swedish upper secondary school chemistry textbooks. The dimensions of NOS were analyzed from five popular chemistry textbook series. The study provides a quantitative method for analysis of representations of NOS in chemistry textbooks informed by domain-specific research on the philosophy of chemistry and chemical education. The selection of sections analyzed was based on the four themes of scientific literacy: knowledge of science, investigate nature of science, science as a way of thinking, and interaction of science, technology and society. For the second round of analysis the theme of science as a way of thinking was chosen for a closer inspection. The units of analysis in this theme were analyzed using seven domain specific dimensions of NOS: tentative, empirical, model-based, inferential, technological products, instrumentation, and social and societal dimensions. Based on the inter-rater agreement, the procedure and frameworks of analysis presented in this study was a reliable way of assessing the emphasis given to the domain specific aspects of NOS. All textbooks have little emphasis on the theme science as a way of thinking on a whole. In line with the differences of curricula, Swedish textbooks emphasize the tentative dimension of NOS more than Finnish textbooks. To provide teachers with a sufficiently wide variety of examples to discuss the different dimensions of NOS changes to the national core curricula are needed. Although changing the emphasis of the curricula would be the most obvious way to affect the emphasis of the textbooks, other efforts such as pre- and in-service courses for developing teachers understanding of NOS and pedagogic approaches for NOS instruction to their classroom practice might also be needed.     

Constructivism and empiricism: An incomplete divorce

The paper outlines the significant influence of constructivism in contemporary science and mathematics education, and emphasises the central role that epistemology plays in constructivist theory and practice. It is claimed that despite the anti-empiricism of much constructivist writing, in most forms its epistemology is nevertheless firmly empiricist. In particular it is subject-centered and experience-based. It is argued that its relativist, if not skeptical conclusions, only follow given these empiricist assumptions. Further it is suggested that such assumptions belong to Aristotelian science, and were effectively overthrown with the modern science of Galileo and Newton. Thus constructivism cannot provide understanding of post-Aristotelian science. Specializations: history, philosophy and science teaching.     

Science Instruction with a Humanistic Twist: Teachers' Perception and Practice in Using the History of Science in Their Classrooms

Scholars have argued that the history of science should be included in the science curriculum because it provides meaningful perspective about scientific concepts, processes, and context. This article begins with a review of efforts to humanize science education by including the history of science, and a review of the rationale for including the history of science in the science education curriculum. The authors then synthesize a conceptual framework for examining the role of the history of science in science education. The framework is organized around realms in the history of science: a) conceptual understanding, b) procedural understanding, and c) contextual understanding, and includes approximately 3 sub-elements within each realm. The framework has been used previously to study the inclusion of the history of science in high school physics textbooks (Wang 1998). In this study, it is used to examine the perceptions and practices of elementary and secondary school teachers in using the history of science in their classrooms. Thirty-eight teachers completed a questionnaire which used Likert scale items to assess their perception of the value of the history of science, and practice in using it in their classroom. A sub-set of teachers were then interviewed to understand the interconnection of these views in more detail. Teachers believe that the inclusion of the history of science should not be used for elementary school students. Teachers who believe in and practice the inclusion of the history of science identify many benefits for their students. However, they believe that it is difficult to include the procedural realm of understanding. The authors conclude that humanizing science isn't a matter of making it fun so much as making it a human and meaningful endeavor.     

Conceptual profile of chemistry: a framework for enriching thinking and action in chemistry education

Understanding the nature of chemical thinking and action, as well as their application and impact on our world should be central goals of chemistry education at all educational levels. However, traditional school chemistry is still mostly focused on having students learn the body of declarative knowledge built over the years in the discipline. Achieving changes in curriculum and teaching practices in this context remains a challenging task. Studies in the history and philosophy of the discipline suggest that chemistry has unique characteristics that need to be recognised and considered in chemistry education. Many of these studies point to a pluralism in the discipline, and in the understanding of and about chemistry, that should be characterised and incorporated into our educational models. In this essay, we have attempted to build such a characterisation using conceptual profiles theory to propose a framework that can be used to enrich and support the thinking and action of chemistry teachers at all educational levels.     

Teaching Modern Chemistry through ‘Recurrent Historical Teaching Models’

Today there are little more of 3 million chemist all over the world producing about 800,000 papers a year. They produce new substances – from some hundreds in 1800 to about 20 million now – the vast majority artificial. This rate is growing quite fast. Once the majority of chemistry teachers all over the world used textbooks as the main (sometimes the only) source of information, we became, without wanting to... history teachers! If ‘scientific literacy’ is the aim of science lessons in school, it is much more than the literacy now developed in science classrooms. It must include an understanding of the nature and process by which scientific activities are carried out. Recognition of the exponentially chemistry knowledge growth and the incompleteness of the current chemistry textbooks are thus intimately related to recognition of the need for recurrent historical teaching models.     

Instructional Misconceptions in Acid-Base Equilibria: An Analysis from a History and Philosophy of Science Perspective

The implications of history and philosophy of chemistry are explored in the context of chemical models. Models and modeling provide the context through which epistemological aspects of chemistry can be promoted. In this work, the development of ideas and models about acids and bases (with emphasis on the Arrhenius, the Brønsted–Lowry, and the Lewis models) are presented. In addition, misconceptions (alternative and instructional ones) on acid-base (ionic) equilibria are examined from the history and philosophy of science perspective. The relation between the development of the models and students misconceptions are investigated. Finally, the hypothesis that history and philosophy could help educators anticipate students misconceptions is examined.     

Teaching the Nature of Science from a Philosophical Perspective

This paper draws attention to basic philosophical perspectives which are of theoretical and methodological interest for science education, general education and curriculum research. It focuses on potential contributions philosophy class can offer if philosophy education opens up for science and for a collaboration of teachers in the context of post-compulsory education. A central educational goal is to connect basic philosophical skills with any curricular intellectual practice. This implies the possibility of crossing disciplinary boundaries. Hence, the present paper questions the disciplinary rigidity of education and aims at bridging the artificial gap between teaching philosophy and teaching science in order to enrich the individual school subjects involved. Towards this end, this article sketches out a conceptual framework for the issue of interdisciplinarity with regard to philosophy and science in upper secondary school. This framework takes into account aspects of the nature of science (NOS), history and philosophy of science (HPS) and the critical thinking approach which have significant implications for teaching. It aims to facilitate a basic understanding of the significant positive impact philosophy could have on improving scientific literacy as well as decision-making in general. I set forth methods of cross-curricular teaching which can promote innovation in education as interdisciplinarity already does in research since there is growing appreciation of collaboration and partnership between philosophy and science.

     

Philosophy of Chemistry: An Emerging Field with Implications for Chemistry Education

Traditional applications of history and philosophy of science in chemistry education have concentrated on the teaching and learning of history of chemistry. In this paper, the recent emergence of philosophy of chemistry as a distinct field is reported. The implications of this new domain for chemistry education are explored in the context of chemical models. Trends in the treatment of models in chemistry education highlights the need for reconceptualizing the teaching and learning of chemistry to embrace chemical epistemology, a potential contribution by philosophy of chemistry.