Exploring alternative approaches to methodology in educational research

The objective of this study is to provide in-service teachers an opportunity to become familiar with the controversial nature of progress in science (growth of knowledge) and its implications for research methodology in education. The study is based on 41 participants who had registered for a nine-week course on Methodology of Investigation in Education, as part of their Master’s degree program. The course is based on 20 readings drawing upon a history and philosophy of science perspective (positivism, constructivism, Popper, Kuhn, Lakatos) and its implications for educational research. Course activities included written reports, class room discussions based on participants’ presentations, and written exams. Based on the results obtained it was concluded that: (a) participants were able to understand the basic ideas of constructivist philosophy and its pedagogical implications; (b) the role of behavioural objectives in actual educational practice was questioned; (c) integration of qualitative and quantitative research methods was considered to be an alternative to the current debate about the replacement of one method by the other; (d) participants considered the dilemma of evaluating students based on what they have learned or what they should have learned, within the social constructivist framework and generally favoured the former; and (e) most of the participants were reluctant to accept constructivism as a form of positivism, a controversial thesis that is gaining support in the research literature. Given the importance of alternative approaches to growth and meaning of knowledge, it is important that teachers be aware of conflicting situations in the classroom that refer to: objectivity, scientific method, qualitative-quantitative methods, relationship between method and problem, evaluation, and a critical appreciation of constructivism.     

Balancing chemical equations: The role of developmental level and mental capacity

Why are some students able to learn to use the trial and error method to balance chemical equations while others are not? To test the hypothesis that formal reasoning is required to balance even simple one-step equations, while formal reasoning and a sufficiently large mental capacity are required to balance more complex many-step equations, a sample of science students was tested to determine level of intellectual development, mental capacity, and degree of field dependence/field independence. Students were then given classroom instruction in using trial and error to balance equations. As predicted, a posttest revealed significant correlations between developmental level and equation balancing ability for both simple and complex equations. Also, as predicted, mental capacity correlated significantly with complex equations but not with simple equations. Field dependence/field independence played no significant role in performance. Educational implications are drawn.     

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.     

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.     

Working Memory,Mental Capacity and Science Education: towards an understanding of the ‘working memory overload hypothesis’

Abstract

Researchers in science education recognise the importance of information processing capacity as a constraint on the abilities and achievements of science students. This constraint has been referred to as ‘mental capacity’ or ‘working memory capacity’, with the latter leading to the so‐called ‘working memory overload hypothesis’. However, rarely have researchers in this area been explicit as to the nature or theory of the mental capacity or the working memory system to which these terms refer.

In this paper we outline two possible models which have proved useful in studies of information processing in other domains. The first model (of mental capacity) developed by Pascual‐Leone and his colleagues has been applied in science education with varying degrees of success. The second model (of working memory) developed by Baddeley and his colleagues has been very successful in accounting for a wide range of cognitive activity, although it has not been applied to science education hitherto. We conclude that consideration of elements of the working memory framework may well prove fruitful in science education.     

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.     

A Lakatosian Framework to Analyze Situations of Cognitive Conflict and Controversy in Students' Understanding of Heat Energy and Temperature

The objective of this study is to analyze secondary school students' interactions (conflicts, controversies, and arguments) as they participate in an intact classroom activity designed to facilitate their understanding of heat energy and temperature. The study is based on 32 ninth-grade students in a public school in Londrina, Brazil. Results obtained show that the differentiation between heat energy and temperature constitutes considerable difficulties for the students, and can be considered as part of the hard-core of their understanding (Lakatos, 1970, Criticism and the Growth of Knowledge, Cambridge University Press, Cambridge, UK, pp. 91–196). Student interactions (video taped) were classified into an Alternative Model, Transitional Model, and Scientific Model, depending on the degree to which they reflected a progressive transition in their hard-core. Students generally resisted a change in their conceptual understanding. Some students were able to question the hard-core of their beliefs and construct a Transitory Model. Some students experienced a further progressive transition by constructing a Scientific Model, based on the understanding that Temperature only measures the energy of agitation. Methodology used also provided a glimpse of how a particular student grappled with the conflicts in order to facilitate progressive transition in understanding. It is concluded that given the opportunity to discuss, reflect, consider alternative/conflicting situations, students can construct models that increase progressively in their heuristic/explanatory power.     

Pascual‐Leone's Theory of Constructive Operators as an Explanatory Construct in Cognitive Development and Science Achievement

In order for a cognitive construct to be accepted as explanatory, it must specify target behaviours, posit antecendent variables, and procedures, whereby the antecedent variables can be measured independently of behavioural changes. It is hypothesised that Pascual‐Leone's Theory of Constructive Operators can serve as explanatory construct in cognitive development and science achievement, by postulating the following antecedent variables: Mental Capacity, Field Factor, and the Mobility‐Fixity Dimension. Empirical evidence in support of the three variables is presented. It is concluded that the antecedent variables based on the Theory of Constructive Operators not only serve as explanatory constructs in cognitive development, but also provide epistemological tools that can be manipulated and have important implications for educational practice.     

Can the Study of Thermochemistry Facilitate Students’ Differentiation between Heat Energy and Temperature?

The objectives of this study are: (a) Evaluate science major freshman students’ ability to differentiate between heat energy and temperature, after having studied the topic of thermochemistry; (b) ascertain the degree to which students resist change from the caloric to the kinetic-molecular theory; (c) study the ability to differentiate between heat energy and temperature and its relationship to solving a problem of thermochemistry. Science major freshman students (n = 76) were tested on a three-item Test of Heat Energy and Temperature (THT) and a Thermochemistry Problem (TP). Both THT and the TP formed part of a semester exam given after the topic of thermochemistry had been studied in class. Results obtained show that even after having studied thermochemistry in an introductory freshman course, students have considerable difficulty in differentiating between heat energy and temperature. Although, all three items of THT required the understanding of kinetic-molecular theory, percentage of correct responses varied considerably: Item 1 (72%), Item 2 (64%), and Item 3 (51%). A correct response on Item 3 meant that different amounts of water in two different vessels at 100 °C, would have the same average kinetic energy, but the heat energy required to attain 100 °C was different—hence the confusion with heat as a substance (caloric theory). It was found that students who had good conceptual understanding on the TP did not perform significantly (χ ² = 0.023) better on the THT. It is concluded that as science teachers we must be aware of the difficulties associated with the differentiation between heat energy and temperature and hence the need for teaching thermochemistry in order to facilitate conceptual understanding.