Research: Science and Education
A Review and Discussion of Epistemological Commitments, Metacognition, and Critical Thinking with Suggestions on Their Enhancement in Internet-Assisted Chemistry Classrooms Chin-Chung Tsai Center for Teacher Education, National Chiao Tung University, 1001 Ta Hsueh Rd., Hsinchu 300, Taiwan ROC;
[email protected] A growing number of educators are examining students’ “internal control” of learning and they highlight the importance of this cognitive control for meaningful learning or memory performance (1, 2). Learners’ epistemological commitments, metacognitive processing of their own learning behavior, and critical thinking are viewed as important aspects of internal learning control. Therefore, exploration of these domains becomes essential in education generally, and particularly in chemical education, where formal learning and reflective thought are needed to achieve mastery of the subject. This paper presents some current perspectives on epistemological commitments, metacognition, and critical thinking, and then discusses how Internet technology may help chemistry students develop relevant beliefs and skills toward improving their mastery of knowledge and skills in chemistry. Definitions Epistemological Commitments Epistemological commitment is one of the major features in an individual’s “conceptual ecology” (the dynamic interaction among conceptual and cognitive domains) (3). Epistemological commitments involve an individual’s explanatory ideals— that is, her or his specific views about what counts as a successful explanation in the field (e.g., chemistry)—and his or her general views about the character of knowledge (4 ). Epistemological commitments are evaluative standards used to judge the merits of knowledge, such as its generalizability, internal consistency, and parsimony (5). In the case of complex learning, where conceptual conflicts may occur between an individual’s personal (sometimes scientifically naive) knowledge and the formal ideas of a discipline, these commitments may be among the most important components of an individual’s conceptual ecology (6 ). For example, if a person believes that chemical laws do not have internal consistency, he or she may learn the laws by rote and in isolation without a coherent understanding. Furthermore, the learner may not recognize a logical conflict if two contradictory scientific ideas exist in his or her cognitive structures.
Metacognition The idea of metacognition, the capacity to reflect upon one’s actions and thoughts, has been largely attributed to Piaget and his coworkers, who saw it as one of the attributes of formal thinkers. However, the basic idea may have been proposed first by Vygotsky, although he did not use this particular term. He asserted that “consciousness and deliberate control are the principal contributions of the school years” (7). Recently, the concept of metacognition has been defined in various ways such as “cognitive monitoring”, “executive processes”, “self-communication”, “knowledge about 970
knowledge”, and “knowledge and cognition about cognitive phenomena” (8). The definition proposed by White and Mitchell may be the most complete and concrete one. They define metacognition as “knowledge of the processes of thinking and learning, awareness of one’s own, and the management of them” (9). That is, metacognition is a selfregulatory skill (or relevant knowledge) whereby the learner monitors his or her own learning processes. Recently, constructivist epistemological models have been widely examined in science education as possible theoretical frameworks to guide instruction (10). Constructivist epistemology assumes that knowledge is created or constructed by the learner on the basis of certain inherent cognitive characteristics of the individual learner and in relation to existing frameworks of knowledge in memory. The substantial complementarity between constructivism and metacognition is manifest in the statement by Gunstone that “an appropriately metacognitive learner is one who can effectively undertake the constructivist processes of recognition, evaluation and, where needed, reconstruction of existing ideas” (11). Hence Scott has suggested that it is helpful to include people’s metacognitive capacity as part of their conceptual ecology (12).
Critical Thinking Critical thinking, or the capacity to apply rigorous logical processes in judging the merits of evidence, is clearly relevant to scientific inquiry and learning of science. It also has been defined in various ways by others. For example, Lipman defines critical thinking as “skillful, responsible thinking that facilitates good judgment because it (i) relies upon criteria, (ii) is self-correcting and (iii) is sensitive to context” (13). Siegel states that “a critical thinker is one who appreciates and accepts the importance and convicting force of reasons” (14 ). Ennis’s definition may be the most widely used; he states critical thinking as “reasonable reflective thinking that is focused on deciding what to believe or do” (15). It is clear that the process of deciding what to believe or do depends on the learner’s epistemological commitments—that is, his or her standards of judging knowledge—and the use of reflective thinking depends on his or her metacognitive processing. Hence Kuhn asserted that critical thinking should be viewed as metacognitive, rather than cognitive (16 ). The Relationships among Cognitive Domains— A Broader Theoretical Framework The concepts of epistemological commitments, metacognition, and critical thinking share many commonalities that may provide a broader theoretical framework for educators. First, all of these concepts highlight the importance of the learners’ ability to apply self-reflection during their own learn-
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Research: Science and Education
ing processes. More than 60 years ago, Dewey suggested the importance of reflective thinking and the development of selfregulatory strategies in educational processes (17). In modern terminology, the emphasis is placed on information processing with the goal of helping meaningful learners to monitor, integrate, and extend their own learning. Meaningful learning occurs when knowledge is integrated within a coherent framework of ideas in memory rather than stored in an arbitrary and isolated manner. According to current standards of excellence in education, students should go beyond merely assimilating course material; they should take an active role in constructing knowledge by critically asking questions, relating new learning to existing knowledge, and developing explanatory schemes that embed knowledge in meaningful contexts. This is opposed to some traditional views of knowledge transmission that emphasize memorization and recall of concepts in a codified way, largely in the same form as they were presented by the teacher. According to a newer understanding of cognition, students who are not skilled in self-reflection during learning and who lack well-organized knowledge structures may deem all new information to be of equal importance and each conception to be unique and individually significant. This again may lead to a strategy of rote memorization and commitment of each part to detailed encoding in memory, but largely as isolated units. Students who lack metacognitive strategies may focus exclusively on learning outcomes (what is to be produced), overlooking the learning process (strategies for information processing), and they tend to use means–end strategies in solving problems. Consequently, their goal of learning is often oriented to achieving high grades but not necessarily to the development of an integrated understanding of the content (18). The ideas of epistemological commitments, metacognition, and critical thinking can be related to the idea of internal control beliefs held by learners, since internal control is effectively achieved when individuals take responsibility for critically assessing what they are doing during learning and why they are doing it. Beliefs about internal control influence a learner’s intrinsic motivation. Studies have found that students who believe they have internal control over their own learning show higher motivation and achieve higher academic performance (19, 20). Moreover, the way learners apply epistemological commitments, metacognitive skills, and critical thinking is highly dependent on their views about the general character of knowledge (e.g., its structure in memory and its relation to how we view the world) as well as their beliefs about how knowledge is created and the nature of learning. Hence students’ epistemologies play an important role in their learning and thinking processes. Siegel asserts that epistemology is a crucial component of an appropriate conception of critical thinking because “the critical thinker must have a good grasp of the nature of reasons, warrant and justification generally, as these notions function across fields, in order both to carry out and to understand the activity of reason assessment” (21). In particular, for science learning in which evidence is grounded in observations of the natural environment, students’ scientific epistemological views influence their outlook on fundamental learning processes. As an example, a college student in Hewson’s study responded that “I think that physics works, can explain everything, and that’s the premise I’m
working on and so when I come up with something that I can’t understand I would like to think it through and explain it to myself ” (italics added) (22). It is clear that his epistemological views of physics influence his epistemological commitments (i.e., the generalizability and internal consistency of physics) and these in turn influence his metacognitive processing. Therefore, some educators suggest that learners’ beliefs about the nature of science play an essential role in their metacognitive and conceptual change processes when learning science (11). That is, the epistemological belief structure that students bring to a scientific learning task can enhance or delimit their ability to apply self-monitoring strategies to facilitate accommodation of new material and make necessary revisions in their understanding of concepts, to incorporate new evidence and new conceptualizations based on defensible evidence. It is further proposed that the development of more appropriate metacognitive strategies should itself be seen as a conceptual change—a change of views about learning, teaching, and the nature of science (23). In a series of research studies, I have shown that students’ scientific epistemological views are related to how they organize scientific information, their learning orientations and preferences, and social interactions in laboratory activities when acquiring concepts of chemistry and physics (18, 24–28). I found that students who held epistemological views more oriented to a constructivist epistemology tended to display better metacognitive activities and employ more meaningful approaches to learning. On the other hand, students who believed in firm answers did not see any significant benefit of practicing metacognition and critical thinking. Hence it is expected that promoting students’ understanding about the constructivist epistemology of science may contribute to the fostering their metacognition and critical thinking, especially if these variables are dynamically linked and not correlated solely due to some third contributory variable. Finally, it is clear that the ideas of epistemological commitments, metacognition, and critical thinking are rooted in the constructivist theory. Constructivists emphasize an active role of the learner during knowledge construction; therefore the learner’s awareness of the importance of monitoring and controlling one’s own learning is of central importance. This is consistent with Confrey’s view that “Constructivism not only emphasizes the essential role of the constructive process, it also allows one to emphasize that we are at least partially able to be aware of those constructions and then modify them through our conscious reflection on that constructive process” (italics added) (29). Earlier research has informed us that traditional teaching activities in science classrooms, and particularly allocation of space in chemistry textbooks, emphasize making new conceptions intelligible, while the inadequacies of existing conceptions and the plausibility and fruitfulness of the new conceptions, which require students’ conscious reflection, are seldom explored1 (6, 30, 31). This situation may be partially caused by the demanding chemistry text content, which includes abundant “bundles of truths”. However, it is increasingly apparent that students need ample time during learning to examine the adequacy of new conceptions, make connections, elucidate the meanings of new ideas, interpret data, develop alternative explanations, and contemplate in a reflective way on learning as recommended in constructivist-based models
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Table 1. A Summar y of Epistemological Commitments, Metacognition, and Critical Thinking Domain
Epistemological Commitments Metacognition
Critical Thinking
Definition
Evaluative standards an individual employs to judge the merits of knowledge
Knowledge of the processes of thinking and learning; awareness of one’s own actions and the management of them
Reasonable reflective thinking focused on deciding what to believe or do
Learning control
Internal
Internal
Internal
In conceptual ecology
Yes
Possibly
No
Orientation
Belief-oriented
Mix of belief and skill
Skill-oriented
of learning (32). This is exactly why a “wait-time” teaching strategy2 was found to have the greatest effect on science learning in a meta-analysis conducted by Wise and Okey (33). The use of wait time can increase the length of students’ responses and their depth of critical thinking as well as the diversity of student-to-student interactions, and thus enhance cognitive outcomes. Table 1 summarizes the major ideas about epistemological commitments, metacognition, and critical thinking in relation to the cognate areas of learning control, conceptual ecology, and belief versus skill orientation. The major differences among these domains are evident in the last two rows of the table. Epistemological commitments and possibly metacognition are features of one’s conceptual ecology, whereas critical thinking may not be; and epistemological commitments are belieforiented, whereas critical thinking is skill-oriented and metacognition is a mix of beliefs and skill. For example, Kuhn believes that metacognition is applied to both declarative knowledge (belief-oriented) and executive management (skilloriented) (16 ). Figure 1 shows further relationships among these three domains. Epistemological commitments are the highest order beliefs guiding metacognition and critical thinking. But on the other hand, the practice of metacognition and critical thinking reciprocally may shape a learner’s epistemological commitments. For instance, if the content of chemistry instruction involves
beliefs
epistemological commitments guide shapes
guide shapes
metacognition
sup
por t
sup
s
por t
skills
s
critical thinking
Figure 1. The relationships among epistemological commitments, metacognition, and critical thinking. The triangular configuration suggests that the cognitive ecology of these three domains depends on a dynamic and balanced interaction. It is important for teachers to help students gain a balanced perspective of the mutually supportive roles of these domains. Skills and beliefs develop in a complementary way and arise from the interaction of the three domains during information processing in learning chemistry.
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more opportunities for students to use critical thinking about concepts, they are more likely to perceive chemistry knowledge as fluid and evolving rather than as a final version composed of isolated truths. Also, metacognition and critical thinking are mutually supportive (16 ). According to the framework in Figure 1, if an individual experiences a cognitive conflict between an existing conception (perhaps a misconception) and a new conception (e.g., a scientific conception), his or her epistemological commitments will guide metacognition and critical thinking to reflect upon the discrepancy and reconcile it in some way. If students practice this self-monitoring process frequently, it is expected that their misconceptions can to a large extent be altered, or even extinguished. In order to foster students’ metacognition and critical thinking, educators need to create learning environments where students are allowed to explain and defend their thinking, opinions and decisions. The goals of chemical education are not only to construct important scientific conceptions, which allow viewing the world in a specific way, but also to develop an ability to critically evaluate one’s own views and those of others (34). How the Internet May Enhance Epistemological Commitments, Metacognition, and Critical Thinking The potential of Internet technology as a medium to enhance learning has recently been recognized, especially in science education (35). Its application within a broad theoretical framework such as the one presented above may create a new vision of student-centered instruction that can enhance learning of formal science concepts. In the following, new perspectives are offered on how Internet technology may help chemistry students develop epistemological commitments, metacognition, and critical thinking.
Epistemological Commitments To help students develop appropriate epistemological commitments, a promising approach for chemical educators is to provide opportunities for students to work with professional scientists and through discourse develop shared understandings of the belief systems, norms, and ways of thought that characterize scientific inquiry. Students can serve as scientific apprentices by examining evidence gathered by scientists during chemical experiments, discussing the significance of experimental results, and exploring the linkages between theories and observations. Such a dialogue between scientists and students also can help students shape a more proper epistemology of science (36 ). Internet technology enables students to have connections with scientists and to practice scientific research without the constraints of time and location. For example, Cohen reported a series of projects from student–scientist partnerships through the assistance of the Internet (35). Post-
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Research: Science and Education
Zwicker et al. also described Internet-based learning environments where high school students could conduct experiments of plasma physics and fusion energy with professional scientists and then acquire real-time data analyses and interpretations (37). In many cases, students do not have to interact with scientists to find scientific reports on the Internet, make interpretations and critical judgments about the evidence, and explore relationships to other such scientific reports on the Internet. There are many of these brief reports, and even interesting methods and anecdotal summaries, online. The students can also respond to the email address and see if the scientists are willing to discuss the information the students have extracted. Through reading these reports and possibly discussing them with professional scientists, students may develop shared understandings and proper epistemological commitments about the ways of thought that characterize scientific exploration.
Metacognition Metacognition will be enhanced if students can monitor and review their learning paths. Internet-based environments have the capacity to record every student’s navigation in the courseware. This record should at some points allow students to review the pathway navigated and evaluate what they did in the course of exploring scientific ideas. The personal learning profiles (e.g., number of nodes visited, time spent on each node, path of navigation) can not only help students monitor their learning and practice metacognition, but also provide indicators for teachers to evaluate students’ performance on the Internet-based courseware. Teachers can use this information to help students better identify their major areas of interest and begin to develop metacognitive strategies by merging these foci of interest within the context of topics and themes addressed in the chemistry curriculum. The rich variety of information on the Internet also may help students develop the metacognitive skill of information organization; that is, keeping track of sources of information and merging them with newly identified information on the Internet. In particular, the hypertext of the World Wide Web is a database of text or content units without predefined order (38). Students can be encouraged to create meaningful categories for declarative and procedural knowledge and sort new information into these categories. In this way they can become more adept at merging special interests with the contextual requirements of the work place, a requisite skill for effective participation in many professional settings. Internet-assisted instructional strategies also potentially allow the teacher more time to interact with students as they pursue projects and to address any special needs students have
in developing metacognitive skills. One of the chief limitations of the traditional classroom with many students is the lack of opportunity for teachers to serve as facilitators helping individual students to develop their potential to be reflective, enhance their particular strategies for acquiring and organizing information, and construct a sense of identity relative to a discipline of inquiry such as chemistry.
Critical Thinking Students may be reticent to engage in scientific inquiry or discussion because they feel intellectually unprepared or socially self-conscious about expressing their thoughts. A major feature of Internet-based environments is the decontextualized nature of the interactions they foster. These interactions allow participants with various perspectives to contribute their ideas in an environment where social status (e.g., academic level) and other social, cultural, and academic contextual factors become less important and critical thinking may become more important. Teachers can use the Internet environment to stimulate a search on some issue (e.g., the development of nuclear or biochemical weapons) and then encourage students’ free discussion. It is expected that some “outsiders” of different professions may join the discussion on the Internet. Students will need to judge the soundness of each argument and use reflective thinking to decide what to believe or do, and their critical thinking will be enhanced by the challenge of diverse viewpoints. The Internet also provides an ideal environment for students’ anonymous peer assessment (39). Internet-assisted peer assessment is a growing area for educational research, though at present there is little relevant literature (40). Teachers can ask students to submit their chemistry projects on the Internet and invite their peers (locally and more broadly) to evaluate the work and give comments online. Chemistry students may then modify their original work on the basis of their peers’ comments. Such assessment procedures can be repeated several times online with the aim of improving project quality. The whole process of peer assessment, either by the assessors or project producers, relies on students’ critical thinking to judge the quality of others’ work or to modify their own work. Features of Internet-Based Activities Table 2 summarizes some possible Internet-based activities for chemistry in relation to the domains of epistemological commitments, metacognition, and critical thinking. The table also lists the features of Internet technology that make these activities possible and effective. The entries in Table 2 suggest that to help students acquire appropriate epistemological commitments, chemistry teachers
Table 2. Internet-Assisted Activities That Enhance Epistemological Commitment, Metacognition and Critical Thinking Domain
Internet-Assisted Activities
Corresponding Feature of Internet
Epistemological commitments
Student–scientist partnerships
Remotely synchronous or asynchronous interactions
Reading numerous scientific reports online
Worldwide information connections
Providing learning profiles for online navigation
Digital storage of student data and interactions
Creating meaningful categories of information on Internet on the basis of personal interest
Hypertext format, worldwide information connections
Online issue-based discussion Online peer assessment
Decontextualized interactions, remotely synchronous or asynchronous interactions Decontextualized interactions, remotely synchronous or asynchronous interactions
Metacognition
Critical thinking
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may provide opportunities for online student–scientist cooperation and discussion. This is all the more effective because the current Internet technology can offer remotely synchronous or asynchronous interactions, and Internet-assisted learning environments can give students a navigation learning profile to assist their metacognitive activities. The Internet’s capacity for digital storage of students’ online behaviors makes this process efficient and comprehensive. Finally, teachers should recognize that cognitive ecology is a dynamic interaction among epistemological commitments, metacognition, and critical thinking and should be aware of the need to help students understand how these cognitive components are interconnected as they pursue inquiry learning on the Internet. Summary and Concluding Remarks Epistemological commitments, metacognition, and critical thinking are important factors influencing chemistry learning, though research in this area is in its infancy and there are few current examples exploring these domains in any detail in chemical educational research (41). The development of epistemological beliefs and cognitive skills in chemistry may also be applied to other school subjects. Chemistry teachers may enhance their opportunity to teach more creatively and improve their students’ ability to assimilate formal ideas in chemistry and scientific research strategies if attention is given to using Internet technology as a resource for developing scientific thinking and learning skills in addition to the more common use of the Internet for seeking knowledge. Acknowledgments Funding of this research is supported, in part, by the National Science Council, Taiwan, ROC, under grant NSC 89-2511-S-009-005. I express my gratitude to O. Roger Anderson for his helpful comments on an early version of this paper. I also very much appreciate the suggestions provided by the Editor and three anonymous reviewers. Notes 1. Posner et al. have proposed there are four conditions for students’ conceptual change in science: (i) there must be dissatisfaction with existing conceptions, (ii) a new conception must be intelligible (i.e., be minimally understood), (iii) a new conception must appear initially plausible, and (iv) a new conception should suggest the possibility of a fruitful research program (3). 2. Wait time means that after a teacher has asked a question and a student has given an answer, the teacher pauses five seconds.
Literature Cited 1. Amrhein, P. C.; Bond, J. K.; Hamilton, D. A. J. Gen. Psychol. 1999, 126, 149–164. 2. McDonald-Miszczak, L.; Gould, O. N.; Tychynski, D. J. Gen. Psychol. 1999, 126, 37–52. 3. Posner, G. J.; Strike, K. A.; Hewson, P. W.; Gertzog, W. A. Sci. Educ. 1982, 66, 211–227. 4. Hewson, P. W. Eur. J. Sci. Educ. 1981, 3, 383–396. 5. Hewson, P. W. Eur. J. Sci. Educ. 1985, 7, 163–172.
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6. Hewson, P. W.; Hewson, M. G. Instructional Sci. 1984, 13, 1–13. 7. Crain, W. Theories of Development; Prentice Hall: Englewood Cliffs, NJ, 1992; p 216. 8. Kitchener, K. S. Human Devel. 1983, 26, 222. 9. White, R. T.; Mitchell, I. J. Stud. Sci. Educ. 1994, 23, 26. 10. Bodner, G. M. J. Chem. Educ. 1986, 63, 873-877. 11. Gunstone, R. F. In Research in Physics Learning: Theoretical Issues and Empirical Studies; Duit, R.; Goldberg, F.; Niedderer, H., Eds.; Institute of Science Education: Kiel, Germany, 1991; pp 129–140. 12. Scott, P. H. In Proceedings of the Second International Seminar: Misconceptions and Educational Strategies in Science and Mathematics; Novak, J. D. Ed.; Cornell University Press: Ithaca, NY, 1987; Vol. II, pp 404–409. 13. Lipman, M. Educ. Leadership 1988, 46 (1), 39. 14. Siegel, H. Synthese 1989, 80, 21. 15. Ennis, R. H. In Teaching Thinking Skills: Theory and Practice; Baron, J. B.; Sternberg, R. J., Eds.; Freeman: New York, 1987; p 10. 16. Kuhn, D. Educ. Res. 1999, 28 (2), 16–26. 17. Dewey, J. How We Think: A Restatement of the Relation of Reflective Thinking to the Educative Processes; D. C. Heath: Lexington, MA, 1933. 18. Tsai, C.-C. Sci. Educ. 1998, 82, 473–489. 19. Connell, J. P. Child Devel. 1985, 56, 1018–1041. 20. Pintrich, P. R. In Advances in Motivation and Achievement: Motivation-Enhancing Environments; Ames, C.; Maehr, M., Eds.; JAI Press: Greenwich, CT, 1989; Vol. 6, pp 117–160. 21. Siegel, H. Synthese 1989, 80, 25. 22. Hewson, P. W. Eur. J. Sci. Educ. 1982, 4, 69. 23. Gunstone, R. F. In The Content of Science: A Constructivist Approach to Its Teaching and Learning; Fensham, P.; Gunstone, R.; White, R., Eds.; Falmer: Washington, DC, 1994; pp 131–146. 24. Tsai, C.-C. Int. J. Sci. Educ. 1998, 20, 413–425. 25. Tsai, C.-C. Sci. Educ. 1999, 83, 654–674. 26. Tsai, C.-C. Int. J. Sci. Educ. 1999, 21, 1201–1222. 27. Tsai, C.-C. Res. Sci. Technol. Educ. 1999, 17, 125–138. 28. Tsai, C.-C. Educ. Res. 2000, 42, 193–205. 29. Confrey, J. In Constructivist Views on the Teaching and Learning of Mathematics; Davis, R. B., Maher, C. A.; Noddings, N., Eds.; Journal for Research in Mathematics Education Monograph 4; National Council of Teachers of Mathematics: Reston, VA, 1990; p 109. 30. Shiland, T. W. J. Res. Sci. Teach. 1997, 34, 535–545. 31. White, R. T.; Gunstone, R. F. Int. J. Sci. Educ. 1989, 11, 577–586. 32. Tobin, K.; Tippins, D. In The Practice of Constructivism in Science Education; Tobin, K., Ed.; American Association for the Advancement of Science: Washington, DC, 1993; pp 3–22. 33. Wise, K. C.; Okey, J. R. J. Res. Sci. Teach. 1983, 20, 419–435. 34. Hashweh, M. Z. Eur. J. Sci. Educ. 1986, 8, 229–249. 35. Internet Links for Science Education: Student–Scientist Partnerships; Cohen, K. C., Ed.; Plenum: New York, 1997. 36. Ryder, J.; Leach, J.; Driver, R. J. Res. Sci. Teach. 1999, 36, 201–219. 37. Post-Zwicker, A. P.; Davis, W.; Grip, R.; McKay, M.; Pfaff, R.; Stotler, D.P. J. Sci. Educ. Technol. 1999, 8, 273–281. 38. Beishuizen, J.; Stoujesdijk, E.; Zanting, A. J. Educ. Comput. Res. 1996, 15, 289–316. 39. Tsai, C.-C. Int. J. Educ. Devel., in press. 40. Topping, K. Rev. Educ. Res. 1998, 68, 249–276. 41. Rickey, D.; Stacy, A. M. J. Chem. Educ. 2000, 77, 915–920.
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