The nature of science in science curricula Methods and concepts of analysis

Transcription

1 The nature of science in science curricula Methods and concepts of analysis Sílvia Ferreira Ana M. Morais Institute of Education of the University of Lisbon Revised personal version of the article published in: International Journal of Science Education, 35(16), (2013). IJSE homepage:

2 The nature of science in science curricula: Methods and concepts of analysis Sílvia Ferreira Ana M. Morais Institute of Education of the University of Lisbon INTRODUCTION The idea that science education should integrate a metascientific dimension, related to science construction/ nature of science, aroused out in the twentieth century. Incorporating the nature of science in school science has widely been associated with the relation between science, technology and society (Aikenhead, 2000; Santos, 1999). This means that aspects related to the methodology of science, how science progresses, the relation between science, technology and society, the relations within the scientific community and the psychological characteristics of scientists, should be considered as important dimensions of science education (e.g. McComas & Olson, 1998; Lederman, 2007). According to McComas, Clough e Almazroa (1998), the phrase nature of science is used to describe the intersection of issues addressed by the philosophy, history, sociology, and psychology of science as they apply to and potentially impact science teaching and learning. As such, the nature of science is a fundamental domain for guiding science educators in accurately portraying science to students (p.5). Following these perspectives, science curricula have worldwide given more emphasis to the nature of science (BouJaoude, 2002). The main objective of this article is to divulge methods and concepts that may be used to appreciate the nature of science in science curricula. With this purpose we describe an exemplary study made with a Portuguese curriculum. Portugal has followed the international trend for long namely when, in the academic year of 2001/2002, a curricular reorganization took place at the level of compulsory schooling (ages 6-15) with the application of new organizational guidelines and a new curriculum design. Within this curricular reorganization, two main guiding texts were produced, the Essential Competences (DEB, 2001) and the Curriculum Guidelines (DEB, 2002). The first text sets up the competences to be developed across the various disciplines and the second defines the competences specific of each discipline. At the level of middle school (ages ), the two traditional science disciplines in Portuguese curricula (Physics/Chemistry and Biology/Geology) are now integrated in one same area of Physical and Natural Sciences. The respective curriculum guidelines are presented in parallel in a common text which is unified 1

3 around four organizational themes: Earth in Space, Earth in Transformation, Sustainability in the Earth and Living Better on Earth. The study presented in this article was focused on the theme Sustainability in the Earth (8 th year of schooling, age 14) and is part of a broader research developed by the ESSA Group 1 that was centred on the process of curricular reorganization (Alves, 2007; Calado, 2007; Ferreira, 2007) 2. The study carried out by Ferreira (2007) analyzed the sociological message transmitted by the Official Pedagogic Discourse (OPD) of the Natural Science curriculum and the extent to which that message is a result of the ideological and pedagogical principles of the authors of the curriculum. The study was focused on the OPD dimensions related to the what is taught and the how it is taught, regarding the nature of science. In the first case, science construction and conceptual demand, in terms of the complexity of scientific competences and knowledge, were selected for analysis, and, in the second case, the relation between science and metascience, as discourses of the same discipline (intradisciplinarity), was selected. Intradisciplinarity was also considered when appreciating the conceptual demand of the curriculum 3. The selection of these dimensions derived from results of former studies carried out by the ESSA Group (e.g. Domingos, 1989; Morais, Neves & Pires, 2004) and by other authors (e.g. McComas, Clough & Almazroa, 1998), who all have highlighted their importance in the promotion of high levels of scientific literacy. The form how the OPD is explicated to teachers in the Ministry of Education/Teachers relation (evaluation criteria) was also part of the analysis of the OPD message. It should be noted that the Portuguese educational system is a centralised system. Figure 1 shows a schematic overview of the relations analyzed in the study. Figure 1. Diagram of the relations analyzed in the research (Ferreira, 2007). 2

4 The part of the study presented in this paper is focused on the message of the OPD with respect to the process of science construction and to intra-disciplinary relations between scientific and metascientific knowledge 4. The study addressed the following problem: What is the extent to which the sociological message transmitted by the OPD of the science curriculum considers the nature of science? The following research questions derived from this problem: (1) What is the extent to which the OPD present in the two curricular texts (Essential Competences and Curriculum Guidelines) contains the process of science construction and the intra-disciplinary relations between scientific and metascientific knowledge?; and (2) What is the extent and direction of the recontextualization process that may have occurred when passing from the Essential Competences to the Curriculum Guidelines? THEORETICAL FRAMEWORK The study is mostly based on epistemology and sociology namely Ziman s theorization of science construction (1984, 2000) and Bernstein s theory of pedagogic discourse (1999, 2000). According to Bernstein, the pedagogic discourse is determined by a complex of relations that are a consequence of the intervention of different fields and contexts, from the State field at the macro-level to the classroom at the micro-level. The General Regulative Discourse (GRD) is produced in the State field as a result of the influence of the international field, the economy field (physical resources) and the field of symbolic control (discursive resources). The official recontextualising field (represented by the Ministry of Education and its agencies) is a field where the GRD is recontextualised to produce the official pedagogic discourse which is institutionalised in texts namely syllabuses and curricula. Such recontextualising process is also influenced by the field of economy, the intellectual field of education (part of the field of symbolic control) and the international field and also and mostly by authors ideologies. According to Neves and Morais (2001): The message of this official text contains the principles and norms which constitute the general regulative discourse that characterizes a given socio-political context. However, as a pedagogic text, it also carries a message that reflects a set of options considered adequate to a given educational context, which are they themselves influenced by the various fields. (p.226). These options include, among others: the knowledge and competences to be acquired; the nature of relations between the various types of knowledge within a discipline (intradisciplinary relation) and between the various types of knowledge of the discipline and the 3

5 knowledge of other disciplines of the curriculum (interdisciplinary relation); the form of pedagogic interaction that should be present in the teacher-student relation (privileged model of theory of instruction). These options define the what and the how of the OPD, that is, the discourses to be transmitted and the form how these discourses are to be transmitted in the teaching-learning context. The model shows that the pedagogic discourse is not the mechanical result of the dominant principles of society, since recontextualizations may occur at the various levels of the pedagogic device. These recontextualizations create spaces of change and for that reason the discourse that is produced (OPD) and the discourse that is reproduced in the classroom do not correspond strictly to the general regulative discourse. The pedagogical discourse transmits, as a sociological message, specific power and control relations between the following categories: spaces (teacher-student space and student-student space), discourses (between disciplines, within a discipline and academic-non academic) and subjects (Ministry of Education-teacher, teacher-student and student-student). These relations reflect, to a greater or lesser extent, the relations legitimized by the underlying GRD, depending on the recontextualization process that has occurred. In order to analyze power and control relations, Bernstein (1990, 2000) used, respectively, the concepts of classification and framing. Classification refers to the degree of maintenance of boundaries between categories (subjects, spaces, discourses). The more distinct the separation between categories the stronger classification will be. Framing refers to the social relations between categories, that is, to communication between them. Framing is strong when the categories with higher status (e.g. Ministry of Education) have the control in the relation and is weak when the categories with lower status (e.g. teachers) have also some control in the relation. Classification and framing can, within given limits, vary independently, for example, a strong classification can coexist with a weak framing. Bernstein s theory opens up new and promising ways of looking at curriculum (OPD) construction. In the case of the part of the study described in this article it allows to appreciate with more rigor the relative status that is accorded by curriculum authors to the nature of science discourse (in its various dimensions) in relation to the science knowledge discourse and how explicit are directions given to teachers and textbook authors. It also allows to appreciate the recontextualizing processes that may occur within the official recontextualizing field, that is in the Ministry of Education. The consequences for teachers practices and students scientific literacy can then be explored on a more sound basis. 4

6 This study follows Ziman s conceptualization of science construction (1984). According to this author, science should be faced as a social institution with four main metascientific dimensions: philosophical, historical, psychological and sociological. The philosophical dimension of science emphasizes the methodological aspects of science, that is, the methods used by scientists when doing science. "The philosophy of science analyses theories about science construction, the conditions that validate them and the various scientific methods used" (Fontes & Silva, 2004, p.18). These methods include, for example, observation, experimentation and theorizing, and are considered by Ziman (1984) as elements of a specific method of obtaining reliable information about the natural world. The historical dimension of science emphasizes its aspect of archive the accumulation of scientific knowledge, organized into coherent theoretical schemes and divulged in publications is a historical process with special meaning. Scientific knowledge becomes meaningful when it is made public, therefore allowing to restructure universal theoretical schemes and use them for the benefit of humanity (Ziman, 1984). Thus, the historical dimension presents science as a dynamic activity which evolves over time. The psychological dimension of science focuses on the psychological characteristics of scientists which influence their scientific work. It should be noted that, since science is a human activity and therefore subject to the constraints of human nature, it may entail, as any other activity, correct or less correct procedures (Ziman, 1984). The sociological dimension of science entails two sub-dimensions, the internal sociological and the external sociological dimensions. The first involves the social relations that are established and operate within the scientific community. The second is related to scientific production in its relations to the various social actors. With regard to the internal sociological dimension of science, Ziman (1984) notes that scientists are part of a scientific community, establishing social interactions with each other as scientists. Thus, scientists communicate with each other, sharing perspectives and experimental results that lead them to constantly restructure their work, to find new ways of research in an enterprise that is increasingly a collaborative process instead of an isolated activity. With regard to the external sociological dimension of science, science is seen as a social institution, embedded in society and carrying out specific functions for society. From this point of view, the worldwide known STS (interaction between science, technology and society) may be considered as part of this dimension of Ziman s conceptualization of science construction (1984). Thus, the present 5

7 study departs from other authors (e.g. Aikenhead, 2000; Santos, 1999) 5, and regards the relation STS as the external sociological dimension of science. When studying the introduction of science construction in scientific learning, it is important to be aware of the difference between the structure of the two types of knowledge, scientific and metascientific. According to Bernstein (1999), we can say that metascientific knowledge corresponds to a discourse with a horizontal structure, characterized by a series of parallel languages, and its development is achieved through the construction of a new language, with a new set of questions and relations and highly classified in relation to other pre-existing languages. Scientific knowledge has a hierarchical structure, in which development is achieved through the selection and integration of different concepts in order to achieve a common body of knowledge with higher level of abstraction and explanatory power. The scientific what of science education is knowledge with a hierarchical structure, whereas the metascientific what is knowledge with a horizontal structure. METHODOLOGY General aspects The study made use of a mixed methodology which combines features associated with both qualitative and quantitative approaches (Creswell, 2003; Morais & Neves, 2010; Tashakkori & Teddlie, 1998). A quantitative approach was followed when, for example, in the analysis of curricular texts, several categories and indicators were previously defined on the basis of theory. However, a qualitative approach was also followed whenever empirical data gave a contribution to the definition of categories and indicators. The study followed a dialectical process between the theoretical and the empirical. In this way, we reject the empirical analysis without a theoretical basis and the use of a theory that does not permit its transformation on the basis of the empirical. This dialectics was only possible because the study used an external language of description derived from a powerful internal language of description, as the one created by Bernstein (2000). The analysis of the OPD of the Natural Sciences curriculum for the Portuguese middle school was focused on two curricular texts: National curriculum for basic school Essential competences (DEB, 2001), particularly the section devoted to competences for Physical and Natural Sciences; and Curriculum guidelines for basic school (DEB, 2002), specifically the section devoted to the discipline of Natural Sciences. The analysis was centred on the theme 6

8 "Sustainability in the Earth. The analysis required that the whole text of both documents related to that theme was segmented into units of analysis: 76 units of analysis in the case of the Essential Competences (pages 129 to 135 and 140 to 143) and 91 units in the case of the Curriculum Guidelines (pages 4 to 10 and 22 to 30). A unit of analysis was considered as an excerpt of the curricular text, with one or more periods, which together have a particular semantic meaning (Gall, Borg & Gall, 1996). Whenever lists of items were present in the curricular text, as in the case of competences and learning activities, each one of the items was considered as a unit of analysis. Each scheme/diagram was considered as a unit of analysis. The study of the OPD of the Natural Sciences curriculum, with regard to the nature of science, followed the diagram of Figure 2. The analysis was focused on the instructional dimension of the transmission/acquisition context, that is, on the discourses (knowledge and competences) to be transmitted/acquired, and considered two aspects: the what the Ministry of Education legitimates as the OPD of the curriculum, related to the discourses to be transmitted/ acquired; and the how these discourses are to be transmitted in the teachinglearning context, related to the principles that regulate the transmission/acquisition of the discourses. The study was also focused on the Ministry of Education-teacher relation. Figure 2. Scheme of analysis of the nature of science in the Natural Sciences curriculum. 7

9 The analysis of the what of the OPD present in the curriculum was focused on the characterization of the knowledge related to science construction (metascientific knowledge) and respective level of complexity. The analysis of the how of the OPD was focused on the relation between discourses by analyzing specifically the degree of relation between scientific and metascientific knowledge. These intra-disciplinary relations were characterized by using the concept of classification. The Ministry of Education-teacher relation was also studied by analyzing the degree of control given by the Ministry of Education to teachers degree of explicitness of OPD with regard to metascientific knowledge and to the relation between scientific and metascientific knowledge. The degree of explicitness was characterized by the concept of framing. The part of the study presented in this paper is focused on the message of the OPD with respect to the metascientific knowledge and the relations between scientific and metascientific knowledge. Instruments construction and application In order to carry out the analysis of the OPD of the two texts Essential Competences and Curriculum Guidelines instruments 6 were constructed, piloted and applied. These instruments were based on models/ instruments constructed in former studies of the ESSA Group for the analysis of science curricula (e.g. Castro, 2006). For each one of the aspects under study, the instruments were organized to contain the four main sections usually present in any syllabus: (a) Knowledge; (b) Aims; (c) Methodological Guidelines; and (d) Evaluation. Thus, each unit of analysis was associated with one of those four sections and analyzed by using the various instruments constructed. This was a joint task of three researchers validated later on by two other researchers. The description of the instruments starts with the instruments related to the characterization of science construction and respective explanation, followed by the instruments focused on the relation between scientific and metascientific knowledge and respective explanation. Characterization of the process of science construction In order to characterize the process of science construction two instruments were constructed: (1) instrument for characterizing the process of science construction, in terms of the conceptualization level of metascientific knowledge; and (2) instrument with knowledge and 8

10 cognitive competences related to science construction dimensions, as conceptualized by Ziman (1984, 2000). The first instrument (Instrument 1) was constructed taking into consideration the nature and complexity of metascientific knowledge, as well as the development of competences related to metascience. Both knowledge and competences were considered at the level of the main dimensions of science construction suggested by Ziman (1984): philosophical, historical, psychological, external sociological and internal sociological. This instrument included the four sections considered in the study (knowledge, aims, methodological guidelines and evaluation) and each section contained descriptors corresponding to four degrees of complexity of metascientific knowledge, for each dimension of science construction. A four degree scale was made on the basis of the following criteria: Degree 1 corresponds to the absence of knowledge related to the dimension of science construction under analysis, and also to the absence of competences associated with that dimension. Degree 2 may correspond to one of three distinct situations: (i) reference to simple order knowledge related to the dimension of science construction under analysis, but without using that knowledge to develop competences associated with that dimension; (ii) reference to competences development, but with no relation to the process of science construction; or (iii) reference to simple order knowledge, and simultaneously to the development of competences associated with the dimension of science construction under analysis. Degree 3 corresponds to complex order knowledge related to the dimension of science construction under analysis, but without using that knowledge to the development of competences associated with that dimension. Degree 4 corresponds to complex order knowledge and, simultaneously, to the development of competences associated with the dimension of science construction under analysis. According to this four degree scale, the lowest degree is the least desirable for a science education that promotes a high level of scientific literacy and the highest degree is the most desirable. It should be noticed that the various situations presented in the degree 2 descriptor came out of a former exploratory analysis of the units of analysis of both curricular texts. The second part the descriptor is a consequence of the fact that the curriculum frequently indicates the development of competences (e.g. investigative) without relating them to the process of science construction. Table I presents an excerpt of this instrument, for the section Knowledge and for the external sociological dimension, and examples of units of analysis of the curriculum which illustrate different degrees of complexity. 9

11 Table I. Characterization of the process of science construction - Excerpt of the Instrument 1 Section Knowledge Dimensions of Science External sociological dimension Degree 1 Degree 2 Degree 3 Degree 4 Knowledge related to the external sociological dimension of science is not mentioned nor are mentioned competences associated with this dimension Simple order knowledge related to the external sociological dimension of science is mentioned, but that knowledge is not used in the development of competences associated with this dimension; and/or Development of competences related to the external sociological dimension of science is mentioned but with no relation to the process of science construction. Complex order knowledge related to the external sociological dimension of science is mentioned, but that knowledge is not used in the development of competences associated with this dimension. Complex order knowledge related to the external sociological dimension of science is mentioned as is the development of competences associated to this dimension. Units of analysis: Degree 1: With respect to the cycles of matter, it is not intended to analyze the various biogeochemical cycles, but to highlight the existence in communities of groups of living things with activities in a way complementary (producers, consumers and decomposers), which enable the permanent recycling of matter. (Curriculum Guidelines, pp.23-24). Degree 4: [...] by understanding the potentialities and limits of Science and of its technological applications in Society. On the other hand, it allows one to become aware of the scientific, technological and social meaning of human intervention on Earth and this may constitute an important dimension in terms of a desirable education for citizenship. (Essential Competences, p.134). The need of both a referential and consistency when applying Instrument 1 required the construction of an auxiliary instrument (Instrument 2). This instrument contained lists of various types of knowledge of simple and complex order and also of cognitive competences, all related to the various dimensions of science construction (Ziman, 1984, 2000). When developing this definition, simple order knowledge included generalized facts and simple concepts and complex order knowledge included complex concepts and unifying themes. The competences related to metascience were defined in association with particular dimensions of science construction and by reference to the science field rather than to any one knowledge field, the instrument was designed to analyse science curricula. However, it should be noted that some of the competences selected may also be developed within disciplines other than science. Competences were not grouped in terms of degree of complexity, something that is considered as a limitation of the study. Analysis of competences was restricted to the cognitive domain, therefore excluding the social and emotional competences. Table II shows an excerpt of the instrument for case of the external sociological dimension. 10

12 Table II. Knowledge and cognitive competences of science construction dimensions Excerpt of the Instrument 2 External Sociological Dimension Simple order knowledge: Scientific observation is more rigorous with the invention of more complex technologies Technology and Science relation. The evolution of scientific knowledge allows the development of new technologies Science and Technology relation. Complex order knowledge: The application of science to society has both positive and negative effects (political, social, economic and ethical), at short and long term Science and Society relation. The use of science and technology in solving social, personal and environmental problems has potentialities and limitations S-T-S relation. Cognitive competences: Development of critical thinking: selection, analysis and critical evaluation of scientific information in real social situations; reflection of scientific arguments on controversial social issues. Development of communication competences: understanding, interpretation and synthesis of scientific information disseminated by the media. Intra-disciplinary relations between scientific and metascientific knowledge In order to characterize the intra-disciplinary relations between scientific and metascientific knowledge, an instrument was constructed to evaluate the degree of relation between scientific and metascientific knowledge (Instrument 3). This relation was given by a four degree scale of classification (C ++, C +, C -, C - - ) with an increasing degree of relation. Table III presents an excerpt of this instrument for the section Aims. This is followed by examples of units of analysis of the curricular texts which illustrate different levels of classification with regard to intra-disciplinary relations. Table III. Evaluation of the degree of relation between scientific and metascientific knowledge Excerpt of the Instrument 3 Section C ++ C + C - C - - Aims The aims are only focused on scientific knowledge. Or The aims are only focused on metascientific knowledge. The aims are focused on scientific and metascientifc knowledge, but do not make the relation between them. The aims are focused on the relation between scientific and metascientific knowledge, being given higher status to scientific knowledge in this relation. The aims are focused on the relation between scientific and metascientific knowledge, being given equal status to these two types of knowledge in this relation. Units of analysis: Degree C st part: With respect to this subject, students interpretation of the various examples of interactions should be valued, benefits and losses to living beings involved being identified, rather than the simple application of terminology. (Curriculum Guidelines, p.23). Degree C - - : Recognition of the need for treatment of waste materials in order to prevent their accumulation, considering the economic, environmental, political and ethical dimensions. (Essential Competences, p.143). 11

13 The application of each one of the instruments to all units of analysis of both curricular texts of Natural Sciences was followed by the analysis of the results, where each text was analyzed separately. ANALYSIS OF DATA Characterization of the process of science construction In order to characterize the process of science construction contained in the two curricular texts under study, the relative frequency (in percentage) of the excerpts analyzed was determined according to the four degree scale and considering each one of the metascientific dimensions. The graph of Figure 3 shows the results of this analysis for the philosophical dimension. Results are organized by considering each one of the four sections of the curricular texts separately and the sections taken together. The graph of Figure 3 shows that, when both curricular texts are considered as a whole, most of the excerpts analyzed do not include knowledge of the philosophical dimension of science construction and do not also consider the development of metascientific competences associated with this dimension (degree 1). Most of the excerpts classified with degree 2 correspond to the second part of the respective descriptor, that is, the excerpts indicate the development of competences associated with the philosophical dimension of science but do not indicate their relation to the respective metascientific knowledge. This global trend was also found in the various sections of the curriculum, with the exception of the Methodological Guidelines, where degree 2 overcomes slightly degree 1. This was mainly a consequence of the fact that strategies suggested in this section focused only on competences rather than on knowledge associated with the philosophical dimension of science. The excerpts that follow illustrate this fact: Develop experimental work and have the opportunity to use different tools of observation and measurement. [ ] hypothesis formulation and results prediction, observation and explanation should take place (Essential Competences, pp ) Within the study of this topic, experimental activities can also be done in order to observe, for example, the influence of light on plant development. (Curriculum Guidelines, p.22) 12

14 Figure 3. Philosophical dimension of science in the Natural Sciences curriculum: Essential Competences (EC) and Curricular Guidelines (CG). Figure 3 also shows that degree 3 only occurs in the excerpts of the Essential Competences text there are excerpts in the Knowledge section where it is mentioned complex order knowledge related to the philosophical dimension of science. It should be noted, however, that this section includes few excerpts with only one of them being classified with degree 3. When the Knowledge and Aims sections are considered, a slight decreasing of the valuing of the philosophical dimension occurs, when passing from the Essential Competences (the general principles) to the Curriculum Guidelines (the specific principles to the discipline). In the case of the Evaluation section, the Essential Competences text does not contain any excerpts that focus on the assessment of metascientific knowledge and competences. The small number of excerpts of that section in the Curriculum Guidelines text do not allow any conclusions. The same happened when analyzing the other dimensions of science. Data from the analysis of the historical dimension of science shows that, when both curricular texts are considered in their entirety, the vast majority of the excerpts analyzed did not include either knowledge or metascientific competences associated to this dimension (degree 1 around 80%). All excerpts classified with degree 2 correspond to the second part of the description for this degree, that is, these excerpts point out to the development of competences associated to the historical dimension of science but not to its relation to the construction of science. The only section that contains some complex order knowledge (degree 3 6%) is the Aims section in the Essential Competences text. 13

15 The case of the psychological dimension of science is an extreme case because both knowledge and competences related to this dimension are virtually absent 99% of the excerpts were classified with degree 1. The only excerpt classified with degree 2 is included in the section Methodological Guidelines and corresponds to the first part of the description of this degree, that is, this excerpt is restricted to the transmission/acquisition of knowledge of a simple order. Data from the analysis of the internal sociological dimension of science shows that, when both curricular texts are analyzed in their entirety, the vast majority of the excerpts did not include either knowledge or competences related to this dimension (degree 1 about 80%). All excerpts classified with degree 2 correspond to competences related to this dimension. In the case of the external sociological dimension of science construction (Figure 4), the data shows that in both curricular texts, and in opposition to other dimensions of science, degree 1 is absent of most of the excerpts analyzed. A greater emphasis is now given to metascientific knowledge of a simple order (degree 2) and of a complex order (degrees 3 and 4), as well as to the development of competences (degrees 2 and 4). This shows that the theme Sustainability in the Earth of the Natural Sciences curriculum accords to the external sociological dimension higher status and higher degree of complexity in the context of the science construction learning. Figure 4. External sociological dimension of science in Natural Sciences curriculum: Essential Competences (EC) and Curricular Guidelines (CG). There is a relative devaluing of the external sociological dimension when passing from the Essential Competences text to the Curriculum Guidelines text, in the case of the Knowledge 14

16 and Aims sections. This, however, should be read by taking into account that the number of excerpts differs in the two curricular texts much lesser excerpts in the Knowledge section of the Essential Competences and much lesser excerpts in the Aims section of Curriculum Guidelines. In the case of the Methodological Guidelines section, it should be noted that the complexity of knowledge of the external sociological dimension is higher in the Curriculum Guidelines. This is of particular importance since this is the section that is more represented in this curricular text. Intra-disciplinary relations between scientific and metascientific knowledge The graph of Figure 5 shows the results of the analysis of the intra-disciplinary relations between scientific and metascientific knowledge. The global results show that half of the excerpts of the Essential Competences text and most of the excerpts of the Curriculum Guidelines text do not make any relation between scientific and metascientific knowledge (C ++ ). Most of these excerpts refer only to scientific knowledge. The results also show that the frequency of excerpts C - (higher status of scientific knowledge) is higher in the Curriculum Guidelines text whereas the frequency of excerpts C -- (equal status of scientific and metascientific knowledge) is higher in the Essential Competences text. The situation of excerpts containing scientific and metascientific knowledge but with no relation between them (C + ) is absent in both curricular texts. Figure 5. Intra-disciplinary relations between scientific and metascientific knowledge in Natural Sciences curriculum: Essential Competences (EC) and Curricular Guidelines (CG). 15

17 This global trend changes when the sections of the curriculum are observed separately. In the Knowledge section of both texts degree C ++ does not now predominate and more emphasis is given to degree C - - in the Essential Competences excerpts and an identical frequency of degrees C ++, C - and C - - in the Curriculum Guidelines excerpts. This seems to be mostly a consequence of authors attempt to relate knowledge of the external sociological dimension of science to scientific knowledge, when addressing the theme Sustainability in the Earth. In the Aims section there is a relative devaluing of the intra-disciplinary relations between scientific and metascientific knowledge when passing from the Essential Competences text (the general principles) to the Curriculum Guidelines text (the specific principles to the discipline). However, this aspect should be read by taking into account that the number of excerpts analyzed in this section is much lesser in the Curriculum Guidelines text. Excerpts of the Methodological Guidelines section of both curricular texts had a very analogous distribution. In this section the Curriculum Guidelines text keeps the global trend, but the Essential Competences text shows a higher frequency of degrees C ++ and C - and a lower frequency of C - - when compared with global results. With regard to the Evaluation section, as it was mentioned before in the characterization of the process of science construction, the Essential Competences text did not focus on the assessing of scientific and/or metascientific knowledge. The Curriculum Guidelines text contained only two excerpts to be analyzed in this section, but assessment of this intradisciplinary relation would not be expected (degree C ++ ). CONCLUSIONS The article intended to divulge methods and concepts for analyzing the nature of science in science curricula. With this purpose an exemplary study was described. This study analyzed the sociological message transmitted by the Official Pedagogical Discourse of the Natural Science curriculum for Portuguese middle school, on the theme Sustainability in the Earth, with regard to characteristics of the teaching-learning process related to science construction metascientific dimensions and intradisciplinarity between scientific and metascientific knowledge. The analysis intended also to appreciate the recontextualization that may have occurred between the two main documents of the curriculum, the Essential Competences (the general principles) and the Curriculum Guidelines (the specific principles to the discipline). At another level, the study intended to explore empirically Bernstein s model of pedagogic discourse (1990, 2000). 16

18 If the level of students scientific literacy recommended by current perspectives of science education is considered, the study raises serious concerns, particularly related to the deficient coverage of the process of science construction in the curriculum and to the weak intradisciplinary relations between scientific and metascientific knowledge. These concerns are directly associated with the low level of conceptualization of the learning recommended, but also with the low explicitness of the characteristics studied (Ferreira, 2007). With regard to the process of science construction, the results showed that, although the Natural Sciences curriculum (the case of the theme Sustainability in the Earth ) focuses on the five dimensions of science construction as conceptualized by Ziman (1984), this curriculum attributes to them differentiated status. In fact, the OPD of the science curriculum gives to the methodology of science a lower status than it gives to the external sociology of science but a somehow higher status than it gives to the internal sociology and history of science. The influence of scientists psychological characteristics on science construction was almost ignored. These conclusions parallel the findings of a study by Calado and Neves (forthcoming) focused on the theme Living Better on Earth (9 th year of schooling, age 15) of the same curriculum. The external sociological dimension came out as the science dimension that has the highest status in both curricular texts, something that may be related to the S-T-S relation mostly valued by the authors of the curriculum 7. The highest status of this dimension is evident not only by its greater representation in the science curriculum, but also by the greater complexity of the knowledge of this dimension. Thus, the science curriculum advocates a students learning with a higher level of conceptualization in the case of the external sociology of science when compared with the other dimensions. As to the philosophical dimension, most of the curricular text containing this dimension was only focused on competences to be developed within the methodology of science, without making any relation to the respective knowledge. These competences correspond to investigative competences which the curriculum, both in general and specific guidelines, aimed to be developed by students when doing practical activities without, however, relating them to the process of science construction. Thus, the results showed that the level of conceptualization of the science curriculum, with regard to the methodology of science, is very low. In this way the curriculum gives a limited view of what science education should be with respect of promoting the relation between products and processes of science. 17

19 In the case of the internal sociology of science, the text of the curriculum was only focused on competences with no relation to knowledge (e.g. concepts) of this dimension. This was also the pattern in most of the curricular text related to the historical dimension of science. The psychological dimension of science is limited to a reference within a general guideline, where authors make a general statement in both curricular texts about epistemological knowledge. It seems that curriculum authors found difficulties to give suggestions to implement that general reference, something that would be particularly crucial in the case of the Curriculum Guidelines. However, it is possible to think that the authors might have decided to assign a low status to this metascientific dimension. Summarizing, the results of this study show not only that science construction is mostly absent in the curriculum but show also a low level of conceptualization of the science curriculum with reference to science construction. One of the many possible explanatory hypotheses to this fact is related to the horizontal structure of metascientific knowledge (Bernstein, 1999) that, differing from the hierarchical structure of scientific knowledge, may raise difficulties to authors of science curricula in terms of making that kind of knowledge operational. These results depart from the results of a study by McComas and Olson (1998), which analyzed eight international science curricula of the nineties (twentieth century) in terms of the process of science construction. The philosophical and historical dimensions were the dimensions that had a higher status in these curricula. The psychological dimension was the dimension with lower status approximating in this aspect to the Portuguese curriculum. Thus, the curriculum change that is taking place in Portugal is going in the direction of valuing the external sociological dimension of science. This movement that started already with many curricula of the last decades of the past century departed from the changes that occurred internationally in the sixties and seventies when many curricular projects, wanting to introduce science construction in science education, placed the emphasis on the philosophical and historical dimensions (e.g. Biological Sciences Curriculum Study BSCS, 1970). The results showed that recontextualization processes occurred, when passing from the general guidelines to the specific guidelines of the curriculum, in the direction of decreasing the relative value accorded to the process of science construction. This is evidenced in the case of the historical and philosophical dimensions, when the complex order knowledge present occasionally in the Essential Competences is absent in the Curriculum Guidelines. 18

20 Also in the case of the external sociological dimension, the complex order knowledge associated with this dimension is more represented in the Essential Competences. Unlike other studies focused on the analysis of science curricula (e.g. BouJoude, 2002; Neves, Morais, Peneda & Medeiros, 1999), the differences between the sociological message of the general intentions of the curriculum and the specific guidelines of the discipline were not very marked in the Natural Sciences curriculum under study, with reference to the theme Sustainability in the Earth and to the characteristics studied. An explanatory hypothesis for the relative continuity between the two curricular texts is that both documents were constructed by a team of authors, who although not being exactly the same, kept in the team the authors who had more weight whenever curricular decisions were taken 8. With regard to the intradisciplinarity between scientific and metascientific knowledge, the results showed that although there are in some cases intra-disciplinary relations, it is their absence that predominates in both curricular texts. In the study carried out by Calado and Neves (forthcoming), which is focused on the theme Living Better on Earth of the same curriculum, that absence is even more marked, prevailing well defined boundaries between the two knowledge domains. Whenever intra-disciplinary relations occur between scientific and metascientific knowledge, these relations were mostly of the kind where the two types of knowledge have equal status, with little curricular text according greater status to scientific knowledge. This is the opposite of what should occur in a science curriculum where scientific knowledge should have greater status. The authors consider that the situation that better represents a good scientific learning, significantly supported by the understanding and application of metascientific knowledge, would be the one where the scientific domain has higher status in the relation between scientific and metascientific knowledge (degree C - ). This raises the hypothesis that the reason why the authors of this curriculum accorded equal status to both types of knowledge in most of the curricular text may be related to a intention of departing from previous Portuguese curricula of Natural Sciences and therefore making quite clear the importance of including the process of science construction in science education. The degree of recontextualization between the two curricular texts was not significant with reference to this specific characteristic of scientific learning. These findings are in line with those obtained by Calado and Neves (forthcoming) for the theme Living Better on Earth. The Ministry of Education leaves implicit, even when they are present, the metascientific knowledge to be learned, as well the intra-disciplinary relations between scientific and 19

21 metascientific knowledge (Ferreira, 2007), giving therefore more autonomy to teachers in the management of the curriculum, namely on the what and on the how of the teaching of metascience. This large area of intervention accorded to teachers may raise problems, particularly by allowing a greater recontextualization of the OPD when it passes from the curriculum to the classroom. This is of particular importance if we consider that the absence of explicit criteria with respect to the curriculum to be implemented in schools may lead teachers and textbook authors 9, especially those who have scientific and pedagogic deficiencies, to be unable to build on their own, a curriculum that takes into account research findings about the importance of introducing metascience in scientific learning. Thus, the teacher, in the absence of an education that allows him/her to reflect on the significance of the sociological messages contained in the curriculum, may subvert the space of intervention that is given to him/her in a situation of greater control. This is evidenced by Hipkins, Barker and Bolstad (2005) when they focus on the lack of explicitness of the science curriculum in New Zealand, with regard to the process of science construction. According to these authors, the intention was that the teachers had more autonomy in interpreting the curriculum, but this absence of guidance has led teachers to focus science construction on the science and technology relation only 10. Thus the authors consider that, if teachers are to promote an efficient scientific learning, explicit criteria are needed with regard at least to the knowledge and competences to be developed and to the conceptual relation between distinct types of knowledge. This is well discussed by Neves and Morais (2006) when they say: The distinct understanding by teachers/schools of what an efficient learning is, in terms of the specificities of students, schools and their geographic contexts, may constrain, in a context of curriculum flexibility, the success of the reform with regard to the success of all students. In order that the quality of education stands for all students, to make the curriculum flexible does not mean to leave to teachers/schools the selection of the concepts and competences to be learned and of the strategies to be implemented, but the selection, in terms of students specificities, of activities which allow that all of them have access to the same concepts/competences and are exposed to strategies that appeal to similar levels of conceptual demand. (p.90). In spite of the problems it may raise, this large space of intervention given to teachers may also have potentialities which will primarily depend on the scientific and pedagogical education of teachers but also on their teaching-learning conceptions, developed along their professional development. Thus, better educated teachers may have a space of control that allows them to develop science learning processes with a higher level of conceptual demand, by integrating the nature of science in science education. 20