A rational reconstruction of the kinetic molecular theory of gases based on history and philosophy of science and its implications for chemistry textbooks

Research in science education has recognized the importance of history and philosophy of science. Given this perspective, the study was designed to develop a framework for examining the way in which chemistry textbooks describe the kinetic theory and related issues. The framework was developed by a rational reconstruction of the kinetic molecular theory of gases based primarily on the interpretations of Maxwell and Boltzmann, by historians and philosophers of science. Another aspect of the framework was based on an analysis of freshman chemistry students' performance on gas problems that required the use of algorithms or conceptual understanding. Subsequently, 22 textbooks were evaluated using a framework consisting of six criteria. Results obtained showed that most textbooks lacked a history and philosophy of science framework and did not deal adequately with the following aspects: (1) Postulates of the kinetic theory were speculative and played the role of simplifying assumptions, considered to be the rule in science rather than being the exceptions; (2) Based on these simplifying assumptions, the theorists built a series of tentative models that progressively incorporated the behavior of real gases; (3) Similar to other research programs in the history of science, Maxwell's was based on inconsistent foundations; (4) Development of the kinetic theory had to compete with chemical thermodynamics, a rival research program; (5) Maxwell and Boltzmann facilitated our understanding of gas behavior beyond the observable hydrodynamical laws, by explaining the internal properties (e.g., molecular collisions).     

Facilitating Conceptual Change in Gases Concepts

The aim of this study is to investigate the effectiveness of conceptual change oriented instruction (CCOI) over traditionally designed chemistry instruction (TDCI) on overcoming 10th grade students’ misconceptions on gases concepts. In addition, the effect of gender difference on students’ understanding of gases concepts was investigated. The subjects of this study consisted of 74 10th grade students from two chemistry classes. One of the classes was assigned as experimental group and the other group was assigned as control group. The experimental group was instructed with CCOI and the control group was instructed by TDCI. Gases Concept Test (GCT) was administered to both groups as pre- and post-tests to measure the students’ conceptual understanding. The results showed that students in the experimental group got higher average scores from Gases Concept Test. Also, a significant difference was found between the performance of females and that of males in terms of understanding gases concepts in favor of males.     

A Lakatosian Conceptual Change Teaching Strategy Based on Student Ability to Build Models with Varying Degrees of Conceptual Understanding of Chemical Equilibrium

The main objective of this study is to construct a Lakatosian teaching strategy that can facilitate conceptual change in students' understanding of chemical equilibrium. The strategy is based on the premise that cognitive conflicts must have been engendered by the students themselves in trying to cope with different problem solving strategies. Results obtained (based on Venezuelan freshman students) show that the performance of the experimental group of students was generally better (especially on the immediate posttests) than that of the control group. It is concluded that a conceptual change teaching strategy must take into consideration the following aspects: a) core beliefs of the students in the topic (cf. 'hard core', Lakatos 1970); b) exploration of the relationship between core beliefs and student alternative conceptions (misconceptions); c) cognitive complexity of the core belief can be broken down into a series of related and probing questions; d) students resist changes in their core beliefs by postulating 'auxiliary hypotheses' in order to resolve their contradictions; e) students' responses based on their alternative conceptions must be considered not as wrong, but rather as models, perhaps in the same sense as used by scientists to break the complexity of a problem; and f) students' misconceptions be considered as alternative conceptions (theories) that compete with the present scientific theories and at times recapitulate theories scientists held in the past.     

Students' preconceptions of the nature of gases

A total of 1098 students, from second graders to university chemistry students, drew representations of highly magnified views of air at 1.0 atmosphere of pressure and at 0.5 atmosphere of pressure. The drawings were classified and the authors inferred from them a relatively limited number of preconceptions of the nature of gases. Several major trends occurred in the frequencies of these inferred preconceptions held at different grade levels. The majority of the drawings that were not in fairly close agreement with atomic theory seemed to reflect one or more of the following misconceptions: (a) air is a continuous (nonparticulate) substance, (b) gas behavior is similar to liquid behavior, and (c) there is relatively little space between gas particles. The number of drawings that gave evidence of particulate views ranged from 8% for Grades 2–4 to 85% for university chemistry students. However, 33% of the university students' drawings showed highly packed particles, and only 37% showed particles in an approximately correct geometrical distribution. The authors suggest a technique for promoting conceptual change among students who possess alternative views of the nature of gases.     

Effects of Combined Hands-on Laboratory and Computer Modeling on Student Learning of Gas Laws: A Quasi-Experimental Study

Based on current theories of chemistry learning, this study intends to test a hypothesis that computer modeling enhanced hands-on chemistry laboratories are more effective than hands-on laboratories or computer modeling laboratories alone in facilitating high school students' understanding of chemistry concepts. Thirty-three high school chemistry students from a private all-girl high school in northeastern United States were divided into two groups to participate in a quasi-experimental study. Each group completed a particular sequence of computer modeling and hands-on laboratories plus pre-test and post-tests of conceptual understanding of gas laws. Each group also completed a survey of conceptions of scientific models. Non-parametric tests, i.e. Friedman's one-way analysis of ranks and Wilcoxon's signed ranks test, showed that the combined computer modeling and hands-on laboratories were more effective than either computer simulations or hands-on laboratory alone in promoting students' conceptual understanding of the gas law on the relationship between temperature and pressure. It was also found that student conception of scientific models as replicas is statistically significantly correlated with students' conceptual understanding of the particulate model of gases. The findings mentioned earlier support the recent call for model-based science teaching and learning in chemistry.     

EVALUATING STUDENTS’ UNDERSTANDING OF KINETIC PARTICLE THEORY CONCEPTS RELATING TO THE STATES OF MATTER, CHANGES OF STATE AND DIFFUSION: A CROSS-NATIONAL STUDY

This paper reports on the understanding of three key conceptual categories relating to the kinetic particle theory: (1) intermolecular spacing in solids, liquids and gases, (2) changes of state and intermolecular forces and (3) diffusion in liquids and gases, amongst 148 high school students from Brunei, Australia, Hong Kong and Singapore using 11 multiple-choice items that required students to provide explanations for their selection of particular responses to the items. Students’ responses to the items revealed limited understanding of the particle theory concepts, with nine alternative conceptions held by more than 10% of various samples of students. Also, 40.5–78.4% of all students indicated consistent understanding relating to the three conceptual categories based on their responses to the 11 items. However, when their explanations were taken into account, very few students displayed consistent understanding of the related concepts.     

Examining the effects of writing on conceptual and procedural knowledge in calculus

It has been claimed that writing to learn mathematics (WTLM) may benefit students' conceptual understanding as well as their procedural ability. To investigate this claim, we collected data from students in two sections of an introductory calculus course. In one of the sections, students used WTLM activities and discussed the activities after completing the writing; in the other section, students used similar activities that did not involve writing but engaged them in thinking about the mathematical ideas and in discussing the activities. The errors from the in-class and final exams of both groups of students were categorized and analyzed for information about the students' conceptual and procedural understanding. We found no significant differences between the WTLM group and the non-writing group, which suggests that the real benefit from writing activities may not be in the actual activity of writing, but rather in the fact that such activities require students to struggle to understand mathematical ideas well enough to communicate their understanding to others. This revised version was published online in July 2006 with corrections to the Cover Date.     

A Framework to Understand Students' Differentiation Between Heat Energy and Temperature and its Educational Implications

The main objective of this article is to investigate whether students' understanding of heat energy and temperature forms part of a 'hard-core' (Lakatos, 1970) of epistemological beliefs and the degree to which it affects their ability to learn thermodynamics in the classroom. Results obtained based on science major freshman students (n = 99) show that even after having responded correctly in one context that approximates the kinetic view of heat energy students fall back on the caloric theory of heat in a different context. It was also found that there is little relationship between the ability to differentiate between heat energy and temperature and performance on a problem of thermodynamics. Students in this study had been exposed to the kinetic theory in the previous semester and yet some of them had no problem in consistently using the caloric theory, while others switched between the two conceptualizations. It is concluded that an epistemological belief in the caloric theory of heat forms part of the hard-core of students' framework and that the conceptual shift to the kinetic theory requires radical restructuring (Chinn & Brewer, 1993). The question we need to ask is not only what are the students' prior epistemological beliefs, but as to what are the conditions under which the hard-core could crumble. A framework that could facilitate conceptual shifts is formulated.     

Graduation=Unemployment?——Probing into College Students'''' Unemployment

大学生失业已经成为牵系亿万家庭的社会问题。大学生失业具有普遍性、相对性和长期性的特点,具有较大的社会危害。其产生原因在于大学毕业生供需失衡以及就业观念和用人观念存在误区。大学生失业情况的有效缓解需要来自国家、高校、大学生自身以及用人单位的共同努力。     

Secondary students’ ideas about scientific concepts underlying climate change

Abstract

We present ideas about concepts underlying climate change, held by students in years 9 and 10. Misconceptions about climate change are common among students, and may be due to misconceptions about underlying concepts. To investigate this, we developed the Climate Change Concept Inventory (CCCI), and trialed it with 229 students; corroborating findings through focus group interviews. Our interview method and data analysis methods are described. Findings included overestimation of human contributions to atmospheric carbon inputs, ultra violet radiation in sunlight, and greenhouse gases in the atmosphere. Students were unaware that CO₂ dissolves in water, and of the role of oceans in the carbon cycle. Greenhouse gases other than CO₂ were rarely known. Earth’s energy balance and black body radiation were not well understood. There were misconceptions about interactions between electromagnetic radiation and atmospheric gases; and limited understanding of carbon chemistry. The CCCI is available from the corresponding author.     

Comparison of learning in two context-based university chemistry classes

ABSTRACT

Context-based learning (CBL) is advocated as beneficial to learners, but more needs to be understood about how different contexts used in courses influence student outcomes. Gilbert defined several models of context that appear to be used in chemistry. In one model that achieves many criteria of student meaning-making, the context is provided by ‘personal mental activity’, meaning that students engage in a role to solve a problem. The model’s predicted outcomes are that students develop and use the specialised language of chemistry, translate what they learn in the immediate context to other contexts, and empathise with the community of practice that is created. The first two of these outcomes were investigated in two large-enrolment university chemistry courses, both organised as this CBL model, in which students were introduced to kinetic molecular theory (KMT). Sample 1 students (N₁?=?105) learned KMT through whole-class kinaesthetic activity as a human model of a gas while focusing on a problem identifying substances in balloons filled with different gases. Sample 2 students (N₂?=?110) manipulated molecular dynamics simulations while focusing on the problem of reducing atmospheric CO₂. Exam answers and pre-/post-test responses, involving a new KMT context, were analysed. Students in Sample 1 demonstrated a stronger understanding of particle trajectories, while Sample 2 students developed more sophisticated mechanistic reasoning and greater fluidity of translation between contexts through increased use of chemists’ specialised language. The relationships of these outcomes to the contexts were examined in consideration of the different curriculum emphases inherent in the contexts.     

Epistemological beliefs of students and teachers about the nature of science: from ‘baconian inductive ascent’ to the ‘irrelevance’ of scientific laws

The main objectives of this study are to: (a) to investigate students' and teachers' beliefs about the nature of science; (b) to explore the relationship among the students' and teachers' beliefs; and (c) to carry out a rational reconstruction of students' and teachers' beliefs based on a Lakatosian perspective of the history and philosophy of science. Eighty-nine freshman students and 7 chemistry teachers at the Instituto Universitario de Tecnología, El Tigre (Venezuela) were asked to respond to a 4-item questionnaire. Students' and teachers' responses were classified as positivist, transitional or Lakatosian. Most of the students and teachers responded with a very similar positivist approach. Epistemological beliefs of students and teachers in this study can be summarized as follows: a scientific theory has not been proved in its totality, whereas a scientific law has not only been proved, but is also universal, and furthermore, a theory tells us about more complex and explicit things. In view of the Lakatosian interpretation that the conflict is not between theories and laws, but rather between an interpretative and an explanatory theory, it is concluded that science teachers reconsider the dichotomous presentation of scientific progress found in most text books, in terms of theories and laws.     

A Study of Students' Focal Awareness when Studying Science Stories Designed for Fostering Understanding of the Nature of Science

Using Marton's theory of the structure of awareness as a theoretical framework, this study investigated the aspects that students discerned and brought into their focal awareness while they studied four science stories in an instruction designed for fostering understanding of the nature of science (NOS). The data showed that when students studied the stories many focused only on one or two aspects, from among a range, presented in the stories. Further, the aspects of the stories in the students' focal awareness were closely linked to the views of NOS that they developed subsequent to the instruction. Students who focused on certain appropriate aspects acquired adequate views of NOS while those who focused on other aspects acquired inadequate views of NOS. The theory therefore offers a viable explanation for why students often construct idiosyncratic meanings from learning experiences that differ from those intended – by attributing it to students attending to certain aspects rather than others. However, the data also show that students' prior conceptions strongly influence their construction of meanings from the learning experiences. The complementarity of the theory of the structure of awareness and the constructivist view of learning are considered. Implications for classroom practices are discussed.     

Problems, perseverance, and mathematical residue

This paper reports on a qualitative study in which three third grade students were presented with a mathematical challenge related to the volume of a cuboid. The task required the construction of containers and the enumeration of the multi-link cubes¹ held by each of the containers. The study videotaped and investigated the students working as a group through potentially seven different problem solving categories, and how they dealt with the student-generated mathematical dilemmas that surfaced during their exploration of the original problem. The tapes were examined for the problem solving actions that the students demonstrated, and an analysis of the students' counting strategies and solutions explored the connection between the children's spatial structuring and their use of numerical operations in enumerating 3-D rectangular arrays of cubes. The notions of perseverance and control are considered as they emerge during autonomous problem solving and the mathematical residue that results from the developing understanding of volume is discussed.This revised version was published online in October 2005 with corrections to the Cover Date.     

Using Qualitative Research Methods to Ascertain Elementary Students' Understandings of Food Safety

ABSTRACT: Researchers and educators call for educational programs that teach youth about food safety. In this study, researchers used qualitative research methods (interviews and concept mapping) to ascertain elementary students' understandings of food spoilage and preservation benchmarks based on national science education standards. Constructivist learning theory and its attendant qualitative methods framed the study. Few students understood the causes of spoilage and most were unable to discuss the role of bacteria or germs in meat. Students with an understanding of microorganisms clearly explained methods of preventing spoilage, while students who did not understand the microorganism concept could not. Constructivist research methods were fruitful in unearthing students' conceptions related to food spoilage. This research has implications for university food science faculty members interested in strengthening their teaching practice by focusing on helping students develop conceptual understanding.     

‘The city snuffs out nature’: young people’s conceptions of and relationship with nature

This paper reports a study of 384 13–14-year olds’ written responses to open-ended questions about their understanding of and relationship with ‘nature’. Using constant comparative method the responses were coded, categorised and themed. Most students held scientific conceptions of nature (excluding humans) and a utilitarian relationship with nature, a predominantly anthroprocentric worldview. A small number held aesthetic conceptualisations and an intrinsic value relationship: an ecocentric worldview. A substantial number of students however were neither anthroprocentric or ecocentric but rather expressed a conception of and relationship with nature which reflected aspects of Bonnett’s ‘human-related’ relationship (Bonnett, M. 2004. Retrieving Nature: Education for a Post-humanist Age. Oxford: Blackwell). The findings from this study challenge a simple binary approach in which students’ environmental worldviews would be analysed as either predominantly anthroprocentric or ecocentric. Bonnett’s ‘human-related’ relationship to nature reflects a more complex view of the world. Analysis revealed interesting differences, however, between students according to their urban/rural location, gender and school type.     

How do high school students perceive global climatic change: What are its manifestations? What are its origins? What corrective action can be taken?

High school students' ideas about the greenhouse effect and global warming have been sought using a closed-form questionnaire. The students, 702 in all, ranged from grades 5 to 10 across a spectrum of schools, and the incidence of a number of ideas, and the strength with which they are held, have been quantified. Using factor analysis, common themes within students' thinking have been identified; from the nature of the questions posed, and the way in which these ideas are grouped, it appears possible to key into the conceptualization of this phenomenon in the minds of the students. The most general conclusion to be drawn from these results is that many students appear to confuse different major environmental problems. In particular, logical and apparently consistent models are held for the confusion between global warming and ozone-layer depletion. In a similar, but less dramatic fashion, there is a linking to radioactive contamination, acid rain, and even global biodiversity reduction. Within the minds of students, the origins of one problem are confounded with the origins of the others, the repercussions of one are confused with the repercussions of the others, and any environmentally friendly action might be said to help any environmental problem.