«Conceptualizing Pedagogical Content Knowledge from the Perspective of Experienced Secondary Science Teachers Committee: Julie A. Luft, Supervisor ...»
Therefore, the working definition of PCK for this study is as follows: “PCK encompasses the knowledge and its applications that science teachers incorporate into their pedagogical action to facilitate students’ better understanding of scientific concepts and to encourage students’ scientific inquiry by using effective instructional strategies, representations, and assessment tools within diverse teaching situations.” Within the foregoing definition, “scientific inquiry” refers to “the activities of students in which they develop knowledge and understanding of scientific ideas, as well as an understanding of how scientists study the natural world” (NRC, 1996, p.
PCK has been characterized as an experiential knowledge because it is often thought to be developed through classroom experience (Baxter & Lederman, 1999;
Gess-Newsome, 1999; Grossman, 1990; NRC, 1996; Magnusson et al., 1999; Van Driel et al., 2001). Therefore, it is understood that pre-service or beginning teachers usually have limited or minimal PCK. The PCK of expert science teachers involves an integrated understanding of teaching science through “trial and error in teaching situations, continual thoughtful reflection, interaction with peers, and much repetition of teaching science content” (NRC, 1996, p.67). In this aspect, collaborative work between experienced teachers and beginning teachers through professional development programs can be an effective way to foster the growth of PCK of beginning teachers. The deeper PCK base in science teaching held by experienced teachers is closely related to interaction in the collaborative work; through the process of interaction, such a knowledge base provides the foundation and context that helps beginning teachers to develop their own expertise (Wang & Odell, 2002).
Pre-service courses can initiate the development of PCK in science teachers, and so teacher educators need to make a concerted effort to build such knowledge. In order to do this, pre-service science teachers need to be aware of the methods and strategies in science education, and have opportunities to learn about science.
Furthermore, this should occur during the field experience portion of a teacher education program, as well as at the university. PCK is a “transformative” construct, since content and pedagogy are integrated and transformed into classroom practice (Gess-Newsome, 1999).
Gess-Newsome (1999) presents two models for pedagogical content knowledge: the integrative and transformative model. The comparative overview of these two models is presented in Table 1. To make a distinction between the two models, a “mixture versus compound” analogy was used. In the integrative model, the knowledge domains of subject matter, pedagogy, and context tend to exist as separate entities, like chemical elements in a mixture. On the other hand, PCK in the transformative model is recognized as a synthesized knowledge base for teaching, as in a chemical compound.
For beginning teachers the integrative model is more appropriate, since beginning teachers tend to rely more heavily on one domain of knowledge rather than drawing simultaneously from all domains, as is the case with an expert teacher (GessNewsome, 1999). My interpretation is that a variety of conceptualizations of PCK come from these two different viewpoints. With its description of PCK as comprising two primary components knowledge of (1) students and (2) instructional strategies and representations Shulman’s notion of PCK might be equivalent to that of the integrative model. Meanwhile, as other researchers acknowledged PCK as being essentially a transformative model, they expanded the concept of PCK adding other components, including knowledge of subject matter, curriculum, purpose, context, and assessment to the original two components. Since it is hard to draw a distinct line between these two models, however, it may be useful to place PCK on a continuum of models of teacher knowledge, with the integration model at one end and the transformative model at the other end.
Marks (1990) discussed the development of PCK as an integrative process revolving around the interpretation of subject-matter knowledge and the specification of general pedagogical knowledge. Marks also asserted that it is impossible to distinguish PCK from either subject matter knowledge or general pedagogical knowledge. Also viewing PCK as integrated knowledge, Fernandez-Balboa and Stiehl (1995) suggested that enhancing any of the components would enhance PCK as a whole.
Although conceptualizations of PCK varied greatly, the researchers came to a consensus on the nature of PCK, which is twofold: (1) PCK is the experiential knowledge and skills that are acquired through the classroom experience (Grossman, 1990; NRC, 1996; Baxer & Lederman, 1999; Gess-Newsome, 1999; Magnusson et al., 1999; Van Driel et al., 2001), and (2) PCK is the integrated set of knowledge, concepts, beliefs, and values which teachers develop in the context of the teaching situation (Marks, 1990; Ferdandez-Balboa and Stiehl, 1995; Van Driel et al., 1998;
Gess-Newsome, 1999; Loughran et al., 2001; 2004).
Table 1. Overview of Integrative and Transformative models of teacher knowledge (Gess-Newsome, 1999, p.
In the effort to illuminate PCK through secondary science teachers’ perspectives in the present study, my view, in alignment with several researchers’ views of PCK, is that PCK is the result of a transformation of knowledge of content (subject matter), pedagogy, and context. Given that participating teachers have more than 10 years of teaching experience, their conceptualization of teachers’ knowledge that emerged from interviews and classroom observations is likely to represent their own PCK as a transformative knowledge acquired and shaped by classroom experience. Therefore, it is reasonable to assume that attempting to re-conceptualize PCK from experienced science teachers’ perspectives can provide a more appropriate, relevant guideline for science teachers’ professional development, particularly with regard to PCK.
Since the introduction of the concept of pedagogical content knowledge (PCK), educational researchers have attempted to describe and understand the PCK of teachers. However, accounts of PCK and attempts to measure it have varied greatly.
Table 2 summarizes different conceptualizations of PCK by different researchers.
Elaborating on teachers’ knowledge base, Shulman (1986b, 1987) identified initially two key components of PCK. The first category is knowledge of comprehensive representations of subject matter, which indicates the ways of representing and formulating the subject that makes it comprehensible to others.
Powerful analogies, illustrations, explanations, and demonstrations fall into this category. The second category is a teacher’s understanding of content-related learning difficulties. Knowing students’ preconceptions and which of those are misconceptions a teacher can properly use knowledge of the strategies to reorganize the learners’ understanding.
Many researchers of PCK since Shulman have extended the concept by adding other categories, which are distinct in Shulman’s knowledge base for teaching.
As discussed in the previous section, PCK can be interpreted as being either integrative or transformative, according to researchers’ viewpoints of that knowledge.
Before examining experienced secondary science teachers’ conceptualizations of PCK in the present study, it is necessary to review, in depth, the previous literature in the area. The following paragraphs describe in chronological order, a variety of conceptualization of PCK by different researchers.
In an attempt to refine Shulman’s work, Grossman (1990) developed an expanded definition of PCK that included four central components: (1) conceptions of purposes for teaching subject matter; (2) knowledge of students’ understanding; (3) curricular knowledge; and (4) knowledge of instructional strategies. With this framework she then examined the influence of teacher education on teachers’
knowledge growth. Grossman (1990) also identified four possible sources of PCK:
(1) apprenticeship of observation; (2) subject matter knowledge that influences personal preferences for specific purposes or topics; (3) specific courses during teacher education; and (4) classroom teaching experience. Figure 3 illustrates how these sources affect teachers’ PCK. According to Grossman’s notion, teachers rely on their apprenticeships of observation, their disciplinary backgrounds, and professional education in constructing their PCK. Teaching experience also directly affects the development and refinement of that knowledge.
Figure 3. Conceptual framework of four possible sources of PCK Marks (1990) also expanded Sulman’s notion of PCK through a study that was designed to present PCK in mathematics which was constructed from interviews with fifth-grade teachers.
Analysis of the interviews resulted in extended conceptualization of PCK consisting of four main components: (1) subject matter for instructional purposes; (2) students’ understanding of the subject matter; (3) media for instruction in the subject matter (i.e., texts and materials); and (4) instructional processes for the subject matter. Marks asserted that these components are highly interconnected, rather than existing individual elements. One of the most interesting points in his conceptualization of PCK is that he draws attention to media used as a tool and resource for instruction. Another distinct point of his model is that the area of instructional processes is described extensively and consists of three domains: student focus, presentation focus, and media focus. This component is an expanded version of the “‘knowledge of comprehensive representations of subject matter” that identified by Shulman (1987).
Based on an explicit constructivist view of teaching, Cochran, DeRuiter, and King(1993) renamed PCK as “pedagogical content knowing” (PCKg) to acknowledge the dynamic nature of knowledge development. In their model, PCKg is conceptualized more broadly than Shulman’s view. PCKg is defined as “a teacher’s integral understanding of four components of pedagogy, subject matter content, student characteristics, and the environmental context of learning” (Cochran et al., 1993, p. 266).
Table 2. Different conceptualizations of PCK
PCK: Pedagogical Content Knowledge a: distinct category in the knowledge base for teaching PCKg: Pedagogical Content Knowing b: not discussed explicitly Exploring how university professors construct and implement generic PCK across several fields, Fernandez-Balboa and Stiehl (1995) drew distinctions between two types of PCK: “specific” PCK, which is particular to the instruction of a specific subject or content area; and “generic” PCK, which is common to instruction across all subjects or content areas. Based on the data obtained from interviews with 10 university professors, they identified five components of effective professors’ generic PCK: knowledge about (1) the subject matter, (2) the students, (3) numerous instructional strategies, (4) the teaching context, and (5) one’s teaching purposes.
In the area of science education, there have been attempts to conceptualize the PCK of science teachers by Carlsen (1999); Loughran et al.(2004); Magnusson, Krajcik and Borko (1999); and Tamir (1988). With an extended framework for reorganizing teachers’ knowledge, Tamir (1988) conceptualized PCK in the name of “subject matter specific pedagogical knowledge,” which is comprised of four components: students, curriculum, instruction, and evaluation. Tamir asserted that PCK is a unique area of knowledge handled by instructors who are pedagogical experts in a particular discipline working with student teachers preparing to teach in that discipline. He dichotomized each component into two elements: knowledge and skill. While “knowledge” refers to “propositional knowledge (knowing that),” “skill” refers to “procedural knowledge (knowing how).” (p. 100) Focusing on the training of pre-service biology teachers at college, each category of the framework is explained in detail using specific examples related to the discipline of biology. Given that Tamir’s work is based on the evidence from actual courses in pre-service teacher education, this framework seems to provide a more comprehensive guideline for understanding and developing PCK. Figure 4 presents Tamir’s conceptualization of PCK and examples of each element of subject matter-specific pedagogical knowledge.
Figure 4. Tamir’s conceptualization of PCK
Magnusson, Krajcik and Borko (1999) conceptualized pedagogical content knowledge to be composed of five components. The first component refers to orientations toward science teaching, which represent the general ways of viewing science teaching. The second component relates to one’s knowledge and beliefs about the science curriculum, including goals, objectives, specific curricular programs and materials. Knowledge and beliefs about the students’ understanding of specific science topics is the third component, which includes students’ difficulties and misconceptions associated with specific science concepts. The fourth component consists of a teacher’s knowledge and beliefs about assessment in science, and the last component refers to the knowledge and instructional strategies for teaching science, including both subject-specific and topic-specific strategies.
Defining PCK as different from, but related to, “general pedagogical knowledge” and “subject matter knowledge,” Carlsen (1999) conceptualized PCK with four components: (1) students’ common misconceptions, (2) topic-specific instructional strategies, (3) specific science curricula, and (4) purposes for teaching science. Particularly, he emphasized the first two components with special significance to science education. Carlsen also described topic-specific instructional strategies as “knowledge that science teachers draw upon in choosing and using models, orchestrating substantive classroom discourse, and managing laboratory activities” (p.141).