DO PRIMARY AND SECONDARY TEXTBOOKS CONTRIBUTE TO SCIENTIFIC REASONING?

Marta Massa, Hilda D’Amico, Physics and Chemistry Dept., Facultad de Ciencias Exactas, Ingeniería y Agrimensura, Universidad Nacional de Rosario, Rosario, Argentina

1. The discourse and knowledge representation in science textbooks

Theory and practice of science, as knowledge, are transmitted, explored and re-constructed through the semiotic function of language in classes and textbooks. Lemke (1997) has stated that teachers’ discourse in classes may frequently alienate students as it presents an opposition between a world of impersonal, authoritative and boring facts and their own world of uncertainties, beliefs and interests. Unfamiliar discourses with technical words and mathematical expressions will either bore or attract students, mainly in secondary school. These features may also be attributed to textbooks’ discourse and may act as a model for teachers when they prepare their classes (D´Amico & Massa, 2000). Textbooks have traditionally helped Physics teaching, by introducing a “scaffolding” discourse to construct a conceptual framework and to develop reasoning skills. Therefore, textbooks induce learning situations by means of the provided information, the questions to orient the reader, the proposed activities, the graphic design and the language. Discursive styles of the authors externalise their reasoning and influence readers’ thinking, through the way ideas are supported or contrasted; experiments are designed or beliefs are denied or reinforced (Billig cited in Kuhn, 1991; D´Amico & Massa, 2000). The logical structure and coherence of written discourse may be considered as a good expression of the reasoning that the author develops when he organizes the contents, applies them to certain facts and brings or strengthens the conclusions. The argumentation of the authors, as a way to support or to refuse statements, defines a position towards the construction of knowledge. The language of science has evolved in the construction of a special kind of knowledge – a scientific theory of experience. Science textbooks deal with information and explanations related to facts, processes and devices. Therefore the language is a basic unit to introduce concepts, principles and laws, whose meanings are negotiated by specific figures and expressions provided by the writer in a communicative and constructive process. In this sense, language is viewed as a meaning-making system within a context rather than a meaning-expressing one (Halliday et al., 1993). Theories dealing with information processing assume that external information is registered, codified and processed by subjects before being expressed by actions. Written discourses, drawings, photographs, diagrams are “inputs” for learning processes. In fact, when a subject reads, he integrates the meaning of each sentence in order to construct the global sense of the text within a context. Language comprehension lies on the processing of propositions (assertions, arguments, questions), images and mental models (Johnson-Laird, 1983) as individual representations. The latter are organised dynamically and their meanings are developed in different levels as a result of the comprehension of the text associated with the construction of a mental representation of the stated situation. This process is known as the “resolution of the reference”. The links between the new information and previous knowledge and beliefs, and the inferential processes that derived from them, characterize the style of the discourse, which may be descriptive, informative or argumentative (de Vega et al., 1990). Researchers have identified many problems related to the organization of science textbooks, such as: a “cookbook” approach to experimental activities, scarce attention paid to the development of scientific processes, the introduction of terms preceding the exploration of examples. In addition, the style is descriptive rather than argumentative, with a frequent lack of justification or refutation. Graphic design and structural devices are oriented to attract the attention of the reader rather than promoting reasoning skills (Musheno & Lawson, 1999). Assuming that textbooks are the main source of models of written scientific language for students, they contribute, together with formalized productions of teachers, to construct an alternative

interpretation of the world (science versus common-sense). Therefore four questions emerged: (a) How do textbooks’ discourses contribute to a progressive development of scientific concepts?; (b) What propositional and procedural knowledge is introduced for constructing a formal thinking?; (c) How do authors use the argumentation as a mechanism for conceptual changes?; (d) How are language and language activities (discussion of concepts, questions, formalization, linguistic resources) used to promote understanding? This exploratory study focuses on the development of the concept of ENERGY in science textbooks. Assuming that textbooks provide a relevant discourse that defines an attitude towards Science, we research on the use of argumentation as a resource for a meaningful understanding of these concepts. 2. Method

Thirteen science textbooks, mainly adopted by teachers of the 3rd cycle of the Basic General Education (for students aged 11-14 years) and Physics textbooks for Polimodal courses (students aged 15-17) were analysed (see Table I). The texts contain prose, pictures, diagrams, mathematical expressions and suggested activities throughout the book. The study was focused on the chapters dealing with Energy. Code Title Author- Editor-

Edition Level Grades

A Natural Sciences Santillana - 1997 General Basic Education 8th B Physics Plus Ultra General Basic Education 7th, 8th,

9th C7, C8, C9 Natural Sciences Santillana 2000 General Basic Education 7th, 8th,

9th D Natural Sciences 9 Kapelusz 2001 General Basic Education 9th E Natural Sciences 7 Kapelusz 2000 General Basic Education 7th F7, F8, F9 Natural Sciences and

Technology Aique 2000 General Basic Education 7th, 8th,

9th G Physics I Aique 1998 Polimodal 1st H The Universe of Physics El Ateneo 1997 Polimodal 1st I Physics I Santillana - 1999 Polimodal 1st

Table I. Analysed textbooks Two stages were followed in order to identify textbooks’ structure and strategies to promote learning,: (a) a general approach with four analytical dimensions: conceptual development, structure, language, and proposal of activities; (b) an analysis of the evolution of the argumentation. The latter was done using Toulmin’s scheme (Alvarez Pérez, 1997). It considers the existence of six elements in an argument, and the relationships among them. Three basic elements for comprehensive reasoning are: data [D] (all relevant information related to the events, subjects and objects), conclusion [C] (derived proposition for a general acceptance) and justification [J] (statement that gives continuity to the gap between [D] and [C]). The other three elements, that enrich the reasoning, are: modal qualifiers [M] (intensity with which the data support the conclusion), refutation conditions [Rf] (particular circumstances in which the justification is not valid) and support conditions [Rs]. Refutation [Rf] and support conditions [Rs] sustain the acceptability of the justifications. 3. Results

The first stage of the study involved the identification of the features employed by the author to try to enable the comprehension of the text.

The different dimensions for the analysis of the textbooks, the associated variables and the respective modalities are described in the following paragraphs. Conceptual development I. Central topics: problems related to the use of energy (1) - energy in nature and/or energy

resources (2) - forms of energy, energy transformations (3) - conservation of energy (4) - heat and nuclear energy (5) - electrical energy (6) - physical and chemical changes (7).

II. Energy concept: A concept impossible to define. Energy is transformed and transferred (8) - ability to do work (9) - associated to movement and substance (10) - the total energy of a system is the sum of the macroscopic energy and microscopic internal energy (11) - power to make changes (12) - heat as a form of energy that travels from one body to another due to ∆T (13) - identifiable by its forms (14) - social concepts (bills, home devices) (15).

III. Misconceptions (towards a conceptual evolution): existence (through initial questionnaire) (16) – omission (17) - existence of perpetual mobile (18).

Structure I. Introduction: energy conservation (1) - energy sources (2) - historical reference (3) -

questions related to misconceptions (4) - lab experiments (5) - physical and chemical transformations (6) - scheme as previous organizer (7) - electric energy: generation system, distribution and consumption; conceptual activities (8).

II. Body: work, heat, internal, nuclear, mechanical energy (9) - analysis of forms and principles related to devices and nature (10) - energy: forms and transformations in industries (11) - work and impulse related to kinetic energy and linear momentum (12) - work and kinetic, potential and mechanical energy (13)

III. Conclusion: historical references of applications, reflective and argumentative activities based on papers and Internet sites (14) - historical references of applications, reflective questionnaires (15) - energy transformations in industries and technological devices (16) - work equal to the variation of kinetic energy (17) - reflection on energetic self-sufficiency (18) - environmental effects (19) - W–∆Ek and W–∆Ep , energy conservation and Wfnc - ∆E; work done by gravitational forces along a closed trajectory; analysis of several cases (20).

Language I. Approach: Declarative and descriptive (giving information) (1) - interrogative (demanding

information) (2) - imperative (demanding services or providing instructions) (3). II. Format: photographs with explanation (4) - schemes and related questions (5) - maps (6) -

new concepts in vignette without explanations (7) - caricatured drawings (8) - tables with informative data (9).

III. Formal structure: scientific terminology; definition (without units); principle and laws without formalization (10) - scientific terminology; definition with mathematical expressions without deductions and units (11) - scientific terminology; definition stating dependences between variables (12) - scientific terminology; definition with mathematical expressions and units; principles with formalization (13) – analogy (14)

IV. Questions (related to the frequency of occurrence of each type of question): qualitative description → explanation or justification → complement of description (15) - qualitative description → complement of description→ explanation or justification (16) - qualitative description → complement of description (17) - quantitative description → complement of description→ explanation or justification (18) - explanation or justification → qualitative description (19).

V. Arguments: D → C with J and Rs (20) - D →C with J and M (21) - D →C with Rs (22). Activities Working on misconceptions (1) - experimental activities and related questions (2) - analysis of graphics and tables (3) - explanations to everyday situations (4) - selection of alternatives (5) -

research (6) - debates (7) - calculus (8) - design of devices where transformations take place (9) - use of a dictionary to search for meanings (10) - open situations (11). Table II summarizes the main characteristics observed in each textbook.

Conceptual development

Structure Language Text-book Code I II III I II III I II III IV V

Activities

A 2, 5 9 16 2, 8 9, 10, 11

15 1 4, 5, 9 10 15 22x

2, 3, 4, 11

B 3, 4 10 16 4, 6 10 17 1, 2

4, 5 11 17 22 4, 8

C7 2, 3 14 16 3, 4, 5 10 15 1, 3

4, 5, 6 11 15 20 1, 2,4, 6, 8

C8 2, 3, 4, 5, 7

12,14 17 2, 3, 6 9, 10, 11

14, 15, 19

2, 3

4, 5, 9 1013

15 22 3, 4, 7, 11

C9 5 11, 13 16 3, 4, 5, 7

9 14 1 4, 5 11 15 20 1, 2, 3, 4, 5, 6, 7

D 6 14 16 8 11 16 1 4, 5, 9 14 15 2021

1, 4, 6, 7, 8, 10

E 1 9 17 2 11 18 1 4, 5, 7, 8

12 17 20 1, 2, 7

F7 3, 7 12, 14 16 6 11 16 1, 2

4, 5 10 16 20 2, 5, 8, 9

F8 6, 7 13, 15 17 6, 8 10, 11 16 1 4, 5 10 15 20 2, 4, 9 F9 4, 5 10, 12, 14 17 7 9 17 1 4, 8 11

14 19 20 2, 4, 5, 7,

8 G 4 9, 11, 15 18 1 12 15,

20 1, 2

4 13 14

19 20 5

H 2, 4 9, 14 16 1, 2, 4 11, 13 19, 20 1 4, 6, 8, 9

1314

18 20 1, 3, 4, 6, 9, 11

I 3 8, 14, 15 17 3 10, 11, 12, 13

14, 15, 16, 17, 19, 20

1 4, 5, 8, 9

14 19 20 2, 3, 4, 5, 6, 7, 8, 10

Table II: Main characteristics observed in the analysed textbooks 4. Conclusions

It has been observed that textbooks for EGB3 students offer a general treatment that begins with the analysis of energy in natural processes; followed by the identification of different forms of energy and a slight introduction to principles; while those developed for the 9th year deal with forms of energies that are important for human beings’ activities. They all have a colloquial style, written in everyday language to present examples as scaffolding mental activities, and they use photographs, graphs, vignettes, and any other graphic design to accompany the explanations. Few of them use historical references, experiments and questions as complements to the construction of concepts. Only one text, as can be seen in Table II, centres the treatment on problems derived from energy uses nowadays. As a general perspective, the organisation of these textbooks resembles a schema associated to the intention to construct answers to: why (is it important to know about energy) → how and where (can energy be recognized) → how (do human beings obtain energy to perform their

activities). The main purpose is to introduce scientific language by a close correspondence between words and facts, but not to organize formal thinking. Polimodal textbooks are basically centred on developing a deep and specific conceptual background. Examples are discussed with precision, presented by models and accompanied by demonstrations, diagrams and mathematical expressions. It may be interpreted as the author’s intention to produce a first level of semantic activity within a scientific language, by a close relationship between specific concepts and examples. Analogies are used in this level in order to support statements or as a scaffolding guide to reasoning. These textbooks abandon the narrative and descriptive style seen in EGB3 textbooks to become explicative. Nevertheless, very little argumentative structures, using counterexamples as refutation conditions, have been detected in all the textbooks. Only some of them have been stated as proposed activities to be done by students to complement their study. A question arises in this sense: Do teachers use these activities to organize and to produce an open perspective to science theory? References Álvarez Pérez, V., Los libros de texto, Alambique. 11, (1997). D´Amico H., Massa M., Argumentative Style In Teachers´ And Textbooks´ Discourses, PHYTEB, Barcelona, (2000). De Vega M., Carreiras M., Gutiérrez-Calvo M., Alonso-Quecuty, M., Lectura y comprensión. Una perspectiva

cognitiva, Alianza Editorial, Madrid, (1990). Halliday M., Martin J., Writting science: Literacy and Discursive Power, University of Pittsburgh, Press Pittsburgh,

(1993). Johnson - Laird P. N., Mental Models, Cambridge University Press, Cambridge, (1983). Kuhn D., The skills of argument, Cambridge University Press, Cambridge, (1991). Lemke J. L, Aprender a hablar ciencia. Lenguaje, aprendizaje y valores, Paidós, Madrid, (1997). Musheno B. V., Lawson A.. E.,. Effects of Learning Cycle and Traditional Text on Comprehension of Science Concepts

by Students at Differing Reasoning Levels, Journal of Research in Science Teaching, 36, (1), (1999), 23-37.

e-mail: mmassa@fceia.unr.edu.ar