论化学教师的PCK结构及其建构

教师专业发展的核心问题就是发展他们的PCK。化学教师的PCK主要包括基于化学科学理解的化学学科知识、关于学生理解化学的知识、关于化学课程的知识和化学特定课题的教学策略及表征的知识。教师的PCK是在实践中建构和发展的。PCK的发展是一个非线性的、螺旋发展的动态的过程。化学教师PCK建构的基本策略是:形成促进PCK发展的教学思维方式,提升对化学科学的理解水平,关注学生对于化学的理解,发展化学课程知识,提高整合转化能力,多渠道丰富PCK资源库。     

An exploration of the interactions among the components of an experienced elementary science teacher’s pedagogical content knowledge

This study had two purposes: to explore the components of the pedagogical content knowledge (PCK) of an experienced elementary science teacher and to reveal the presumed interactions among these components. A naturalistic inquiry was conducted as a single case study in which in-depth qualitative data were gathered through semi-structured interview questions. After the theory-based and data-driven analysis of the qualitative data, the verbal communication was quantitated into numerical data for the enumerative analysis. The results revealed that the teacher’s knowledge of students’ understanding and difficulties, knowledge of the elementary science curriculum and knowledge of instructional strategies and representations were found to be mostly intersected PCK components, whereas orientations towards teaching science and knowledge of assessment in science had limited connections to the other components. Further discussions and context-based suggestions are given regarding professional development programmes.     

On-Site Pedagogical Content Knowledge Development

Experiences and reflection have long been regarded as a foundation for pedagogical content knowledge (PCK) development. However, little is known about how experienced teachers develop their PCK via reflection-in-action during their moment-to-moment classroom instruction. Drawing upon data sources including classroom observations, semi-structured interviews and stimulated recall interviews based on lesson videos, this study examined instances when four experienced teachers were found to invent new instructional strategies/representations on the spot during the lesson (referred to as on-site PCK development) in their first attempts at teaching a new topic. The study documented the moment-to-moment experiences of the teachers, including their reconstructed thought processes associated with these instances of on-site PCK development. An explanatory model of a three-step process comprising a stimulus, an integration process and a response was advanced to account for the on-site PCK development observed among the teachers. Three categories of stimulus that triggered on-site PCK development were identified. Factors influencing the integration process and, hence, the resulting response, included teachers’ subject matter knowledge of the new topic, their general pedagogical knowledge and their knowledge of student learning difficulties/prior knowledge related to the new topic. Implications for teacher professional development in terms of how to enhance teachers’ on-site PCK development are discussed.     

Development and Validation of Measures of Secondary Science Teachers’ PCK for Teaching Photosynthesis

This paper describes procedures by which two types of measures of Pedagogical Content Knowledge (PCK) were developed and validated: (a) PCK Survey and (b) PCK Rubric. Given the topic-specificity of PCK, the measures centered on photosynthesis as taught in high school classrooms. The measures were conceptually grounded in the pentagon model of PCK and designed to measure indispensable PCK that can be applied to any teacher, in any teaching context, for the given topic. Because of the exploratory nature of the study, the measures focus on two key components of PCK: (a) knowledge of students’ understanding in science and (b) knowledge of instructional strategies and representations. Both measures have established acceptable levels of reliability as determined by internal consistency and inter-rater agreement. Evidence related to content validity was gathered through expert consultations, while evidence related to construct validity was collected through analysis of think-aloud interviews and factor analyses. Issues and challenges emerging from the course of the measure development, administration, and validation are discussed with strategies for confronting them. Directions for future research are proposed in three areas: (a) relationships between PCK and teaching experiences, (b) differences in PCK between science teachers and scientists, and (c) relationships between PCK and student learning.     

Enhancing pedagogical content knowledge in elementary science

In this study, five elementary teachers and a university researcher developed and implemented problem‐based learning (PBL) experiences in the context of science teaching and learning. Collaborative inquiry was adopted as a methodology, while a variety of qualitative methods were used to examine the engagement and development of teachers’ pedagogical content knowledge (PCK). A PCK model is used as a framework to examine teachers’ professional knowledge growth in areas such as orientations to teaching science, knowledge of science curriculum, knowledge of students’ understanding of science, knowledge of assessment, and knowledge of instructional strategies. Implications for how teachers may be supported when adopting instructional innovations are discussed.     

Not a stale metaphor: the continued relevance of pedagogical content knowledge for science research and education

Recently, theorists have raised concerns that pedagogical content knowledge (PCK) has become “a stale metaphor” that disregards diversity and equity, offers little to help teachers address students’ misconceptions, and portrays knowledge as “in the head” versus in practice. We refute these notions using grounded theory to specify ways one 7th-grade science teacher enacted PCK to advance student learning. With the definition of PCK as knowledge at the intersection of content and teaching, we utilised a framework for science PCK to explore instructional decision-making. Interviews conducted over three years revealed specific ways the teacher enacted PCK by designing and delivering instruction built on each of the seven conceptual science PCK components. The teacher enacted PCK to plan and deliver instruction that was responsive, adaptive, and considerate of changing needs of students and the changing classroom landscape. She infused PCK into instructional decision-making, instructional interactions, and mentoring of a student teacher, modelling the translation of educational theory into practice and habits of mind necessary for expert teaching. This enactment actively refutes Settlage’s critiques, and depicts PCK as a vibrant and effective stance for teaching that enhances learning.     

Representational Classroom Practices that Contribute to Students’ Conceptual and Representational Understanding of Chemical Bonding

Understanding bonding is fundamental to success in chemistry. A number of alternative conceptions related to chemical bonding have been reported in the literature. Research suggests that many alternative conceptions held by chemistry students result from previous teaching; if teachers are explicit in the use of representations and explain their content-specific forms and functions, this might be avoided. The development of an understanding of and ability to use multiple representations is crucial to students’ understanding of chemical bonding. This paper draws on data from a larger study involving two Year 11 chemistry classes (n = 27, n = 22). It explores the contribution of explicit instruction about multiple representations to students’ understanding and representation of chemical bonding. The instructional strategies were documented using audio-recordings and the teacher-researcher’s reflection journal. Pre-test–post-test comparisons showed an improvement in conceptual understanding and representational competence. Analysis of the students’ texts provided further evidence of the students’ ability to use multiple representations to explain macroscopic phenomena on the molecular level. The findings suggest that explicit instruction about representational form and function contributes to the enhancement of representational competence and conceptual understanding of bonding in chemistry. However, the scaffolding strategies employed by the teacher play an important role in the learning process. This research has implications for professional development enhancing teachers’ approaches to these aspects of instruction around chemical bonding.     

Exploring Biology Teachers’ Pedagogical Content Knowledge in the Teaching of Genetics in Swaziland Science Classrooms

This study explored the pedagogical content knowledge (PCK) and its development of four experienced biology teachers in the context of teaching school genetics. PCK was defined in terms of teacher content knowledge, pedagogical knowledge and knowledge of students’ preconceptions and learning difficulties. Data sources of teacher knowledge base included teacher-constructed concept maps, pre- and post-lesson teacher interviews, video-recorded genetics lessons, post-lesson teacher questionnaire and document analysis of teacher's reflective journals and students’ work samples. The results showed that the teachers’ individual PCK profiles consisted predominantly of declarative and procedural content knowledge in teaching basic genetics concepts. Conditional knowledge, which is a type of meta-knowledge for blending together declarative and procedural knowledge, was also demonstrated by some teachers. Furthermore, the teachers used topic-specific instructional strategies such as context-based teaching, illustrations, peer teaching, and analogies in diverse forms but failed to use physical models and individual or group student experimental activities to assist students’ internalization of the concepts. The finding that all four teachers lacked knowledge of students’ genetics-related preconceptions was equally significant. Formal university education, school context, journal reflection and professional development programmes were considered as contributing to the teachers’ continuing PCK development. Implications of the findings for biology teacher education are briefly discussed.     

Science teachers' pedagogical content knowledge development during enactment of socioscientific curriculum materials

The purpose of this study is to provide insight into short-term professionalization of teachers regarding teaching socioscientific issues (SSI). The study aimed to capture the development of science teachers' pedagogical content knowledge (PCK) for SSI teaching by enacting specially designed SSI curriculum materials. The study also explores indicators of stronger and weaker development of PCK for SSI teaching. Thirty teachers from four countries (Cyprus, Israel, Norway, and Spain) used one module (30–60 min lesson) of SSI materials. The data were collected through: (a) lesson preparation form (PCK-before), (b) lesson reflection form (PCK-after), (c) lesson observation table (PCK-in-action). The data analysis was based on the PCK model of Magnusson, Krajcik, and Borko (1999). Strong development of PCK for SSI teaching includes “Strong interconnections between the PCK components,” “Understanding of students' difficulties in SSI learning,” “Suggesting appropriate instructional strategies,” and “Focusing equally on science content and SSI skills.” Our findings point to the importance of these aspects of PCK development for SSI teaching. We argue that when professional development programs and curriculum materials focus on developing these aspects, they will contribute to strong PCK development for SSI teaching. The findings regarding the development in the components of PCK for SSI provide compelling evidence that science teachers can develop aspects of their PCK for SSI with the use of a single module. Most of the teachers developed their knowledge about students' understanding of science and instructional strategies. The recognition of student difficulties made the teacher consider specific teaching strategies which are in line with the learning objectives. There is an evident link between the development of PCK in instructional strategies and students' understanding of science for SSI teaching.     

Identifying pathways of teachers’ PCK development

This paper describes a method of analysing teacher growth in the context of science education. It focuses on the identification of pathways in the development of secondary school teachers’ pedagogical content knowledge (PCK) by the use of the interconnected model of teachers’ professional growth (IMTPG).The teachers (n = 12) participated in a one-year action research project focused on their individual concerns related to teaching science. The use of the IMTPG revealed that teachers use different pathways of learning to develop different aspects of their PCK. For each PCK component, three distinct pathways could be identified, two of which clearly were associated with professional growth. When examining these two pathways in detail, it was found that (1) teachers learned about new instructional strategies and assessment methods mostly through literature reviews and discussions with peers and (2) teachers who analyzed and reflected on student learning as it happened in their classrooms developed understandings that helped them to select and apply instructional strategies to further promote student learning. Both the analytical method as well as the identification of the different developmental pathways help to better understand teacher development in the context of classroom practices.     

Expansion of Biology Teachers’ Pedagogical Content Knowledge (PCK) During a Long-Term Professional Development Program

Experienced teachers possess a unique teaching knowledge comprised of an inter-related set of knowledge and beliefs that gives direction and justification to a teacher’s actions. This study examined the expansion of two components of pedagogical content knowledge (PCK) of three in-service teachers in the course of a professional development program aimed at designing new teaching and learning materials suggested by the teachers themselves. The research presents an enlargement of previous PCK representations by focusing on a detailed representation of two main PCK domains: teaching and learning, including ten PCK components that emerged in the course of data analysis. This representation enabled revealing the unique PCK held by each teacher and to characterize the expansion of the two components of the participating teachers’ PCK during the long-term professional development program. Retention of major parts of the expanded PCK a year after termination of the program implies that designing and implementing new teaching and learning materials based on the teachers’ experiences, needs, and knowledge in a workshop format accompanied by biology and science education courses might provide a powerful means for PCK expansion. We recommend that designers of professional development programs be aware of the unique PCK held by each teacher in order to promote meaningful professional development of each teacher. Moreover, the PCK representations that were identified in the course of this study enabled clarifying the “orientation toward teaching science” category of PCK which appears to be unclear in current literature.     

Exploring challenges of assessing pre-service science teachers’ pedagogical content knowledge (PCK)

The purpose of this paper is to report on the challenges we faced in designing an instrument aimed at measuring pre-service science teachers’ topic-specific pedagogical content knowledge (PCK). After the instrument was conceptualised and developed, it was administered to 30 pre-service chemistry teachers. The findings suggest that the instrument can be used as a teaching tool to enhance pre-service science teachers’ topic-specific PCK along with some limitations. The discussion focuses on the implications of the aforementioned PCK assessment tool for enhancing pre-service science teachers’ topic-specific PCK and the challenges associated with measuring and enhancing pre-service science teachers’ PCK. Finally, our discussion focuses on the ways in which science-teacher educators can engage in transforming the concept of PCK and its use for research and professional development.     

Students’ Perceptions of Their Science Teachers’ Pedagogical Content Knowledge

Pedagogical content knowledge (PCK) is a type of teacher knowledge to be developed by a teacher. PCK is said to contribute to effective teaching. Most studies investigated the development of PCK and its influence on students’ learning from the teachers’ perspectives. Only a limited number of studies have investigated the components of science teachers’ PCK that helped students’ learning from the perspective of students. Thus, it is the aim of this study to investigate the level of science teachers’ PCK from students’ perspective, in particular whether or not students of different achieving ability had different views of teachers’ PCK in assisting their learning and understanding. Based on the PCK research literature, six components of PCK have been identified, which were as follows: (1) subject matter knowledge, (2) knowledge of teaching strategies, (3) knowledge of concept representation, (4) knowledge of teaching context, (5) knowledge of students, and (6) knowledge of assessment in learning science. A questionnaire consisting of 56 items on a five-point Likert-type scale were used for data collection from 316 Form Four students (16 years old). One-way analysis of variance revealed that the differences in science teachers’ PCK identified by students of different achieving abilities were statistically significant. Overall, students of various academic achieving abilities considered all the components of PCK as important. The low-achieving students viewed all the components of PCK as being less important compared to the high and moderate achievers. In particular, low-achieving students do not view ‘knowledge of concept representation’ as important for effective teaching. They valued the fact that teachers should be alert to their needs, such as being sensitive to students’ reactions and preparing additional learning materials. This study has revealed that PCK of science teachers should be different for high and low-achieving students and knowledge of students’ understanding plays a critical role in shaping teachers PCK.     

Effects of biology teachers’ professional knowledge and cognitive activation on students’ achievement

This study examined the effects of teachers’ biology-specific dimensions of professional knowledge – pedagogical content knowledge (PCK) and content knowledge (CK) – and cognitively activating biology instruction, as a feature of instructional quality, on students’ learning. The sample comprised 39 German secondary school teachers whose lessons on the topic neurobiology were videotaped twice. Teachers’ instruction was coded with regard to cognitive activation using a rating manual. Multilevel path analysis results showed a positive significant effect of cognitive activation on students’ learning and an indirect effect of teachers’ PCK on students’ learning mediated through cognitive activation. These findings highlight the importance of PCK in preservice biology teachers’ education. Items of the rating manual may be used to provide exemplars of concrete teaching situations during university seminars for preservice teacher education or professional development initiatives for in-service teachers.     

Learning About Semi Conductors for Teaching—the Role Played by Content Knowledge in Pedagogical Content Knowledge (PCK) Development

This study focuses on how teachers learn to teach a new topic and the role played by their developing content knowledge as they teach. The paper is based on seven high school science teachers’ studies on the teaching of semiconductors, at the time a new topic in the curriculum. Analysis of artefacts such as teacher concept maps, video recordings of lessons, journals and other classroom-based evidence shows how the extent and type of teachers’ content knowledge informed their choice of teaching approaches and how their learning of content took place alongside the development of teaching strategies. The development of content knowledge was combined with increased understanding of how to teach the topic in almost all cases. Evidence of development of teachers’ PCK was found in their increased ability to design teaching strategies, and their use of representations and suitable assessment tasks for their lessons. Some specific common teaching strategies were identified across the teachers. These strategies could add to the canon of teachers’ topic - specific professional knowledge for semiconductors. The study provides increased understanding of how teachers simultaneously master content and its teaching and how mediated self-reflection is a fruitful approach for assisting teachers to learn to teach a new topic.     

The influence of textbooks on teachers’ knowledge of chemical bonding representations relative to students’ difficulties understanding

Background: Textbooks are integral tools for teachers’ lessons. Several researchers observed that school teachers rely heavily on textbooks as informational sources when planning lessons. Moreover, textbooks are an important resource for developing students’ knowledge as they contain various representations that influence students’ learning. However, several studies report that students have difficulties understanding models in general, and chemical bonding models in particular, and that students’ difficulties understanding chemical bonding are partly due to the way it is taught by teachers and presented in textbooks.

Purpose: This article aims to delineate the influence of textbooks on teachers’ selection and use of representations when teaching chemical bonding models and to show how this might cause students’ difficulties understanding.

Sample: Ten chemistry teachers from seven upper secondary schools located in Central Sweden volunteered to participate in this study.

Design and methods: Data from multiple sources were collected and analysed, including interviews with the 10 upper secondary school teachers, the teachers’ lesson plans, and the contents of the textbooks used by the teachers.

Results: The results revealed strong coherence between how chemical bonding models are presented in textbooks and by teachers, and thus depict that textbooks influence teachers’ selection and use of representations for their lessons. As discussed in the literature review, several of the selected representations were associated with alternative conceptions of, and difficulties understanding, chemical bonding among students.

Conclusions: The study highlights the need for filling the gap between research and teaching practices, focusing particularly on how representations of chemical bonding can lead to students’ difficulties understanding. The gap may be filled by developing teachers’ pedagogical content knowledge regarding chemical bonding and scientific models in general.     

Capturing student teachers’ pedagogical content knowledge (PCK) using CoRes and digital technology

During the last decades, digital technologies have become more common in providing opportunities for reflection and in-depth analysis of classroom practices and have afforded new ways of organising teacher education. In particular, videotaped lessons have proven to be a valuable tool for capturing teaching episodes, subsequent reflection and development of student teachers’ professional knowledge, here referred to as ‘pedagogical content knowledge’ (PCK). The aim of this project was to investigate how the use of the reflective tool, content representations (CoRes) in combination with video and associated digital tools might be used as a means for capturing student teachers’ professional knowledge of practice. In the study we explore how a group of 24 secondary science student teachers were provided with Content Representations (CoRe) and video annotations to support their reflection-on-action during their practicum. Video annotations, alongside a written reflection of critical incidents in the student teachers’ teaching constituted data for analysis. Our findings suggest that the different tools enabled the student teachers to connect captured examples of teaching instances with theoretical issues, and in this way offered the ability to see as well as to analyse their teaching practice. As such, the CoRe, together with the video annotation tool, proved to be successful in scaffolding and structuring student teachers’ reflection-on-action, allowing them to connect their reflections to components of PCK and further to articulate connections between these components.     

Developing science teachers' pedagogical content knowledge

This article discusses the concept of pedagogical content knowledge (PCK) within the context of science teaching. First, an attempt is made to define this concept within the tradition of research on teachers' craft knowledge and to identify possible purposes of research on PCK. From this point of view, recent research on science teaching is investigated. This investigation identifies teaching experience as the major source of PCK, whereas adequate subject-matter knowledge appears to be a prerequisite. Finally, an empirical study is presented which focuses on PCK with respect to a specific topic—that is, chemical equilibrium. The effects on teachers' PCK of participation in an in-service workshop and conducting an experimental course in classroom practice are reported. This leads to the identification of elements of PCK teachers can use to promote student understanding. It is concluded that research on topic-related PCK may complement research on student learning of specific topics. © 1998 John Wiley & Sons, Inc. J Res Sci Teach 35: 673–695, 1998.     

Enhancing the Practicum Experience for Pre-service Chemistry Teachers Through Collaborative CoRe Design with Mentor Teachers

This paper reports findings from an ongoing study exploring how the Content Representation (CoRe) design can be used as a tool to help chemistry student teachers begin acquiring the professional knowledge required to become expert chemistry teachers. Phase 2 of the study, reported in this paper, investigated how collaboration with school-based mentors (associate teachers) on teaching practice (practicum) might impact on this process and student teachers’ development of their pedagogical content knowledge (PCK). The collaboration involved identifying and discussing pedagogical issues related to a practicum-teaching topic using a student teacher’s draft CoRe as a starting point and ongoing focus for the professional dialogue. Practicum offered an opportunity for aspects of student teachers’ PCK, as embodied in their draft CoRes, to be explored and expanded upon in classroom programmes with the support and input of associate teachers. The findings were influenced by different contextual factors; however, the student teachers found their CoRes to be very useful frameworks for engaging in focussed professional dialogue with their teaching mentors. They valued the expertise, currency of knowledge and mentoring of their associates and reported positively about the contribution this support made to their PCK development via the CoRe design process and the transformation of the CoRe into classroom teaching.     

Development of evidence-based,student-learning-oriented rubrics for pre-service science teachers’ pedagogical content knowledge

ABSTRACT

This paper offers pedagogical content knowledge (PCK) rubrics, that is, guides providing criteria for grading that are potentially applicable to a range of science topics and levels of teacher experience. Grading criteria applied in the rubrics are based on qualitative analyses of planned topic-specific professional knowledge (TSPK) and content knowledge (CK). Data were collected via three topic-specific vignettes from 239 pre-service science teachers (PSTs) starting a university-based, full-time, one year teacher education programme in England. The statements were analysed for TSPK and CK. PSTs’ statements proposed instructional strategies comprising demonstrations, explanations, illustrations and analogies, classified as Relevant to the science topics, others Irrelevant. Some Relevant strategies missed an aspect that may, if enacted, help students’ learning, so were judged Incomplete. Statements were also analysed for evidence of relevant and correct CK. CK and TSPK statements are aligned into grids, creating PCK rubrics. These demonstrate the precise nature of knowledge likely to lead to instruction that impacts positively on student learning. The rubrics present the possibility of PCK repertoires that contribute clarity and precision to teaching instruction. Although findings cannot be generalised, the methodology offers a strategy for supporting out-of-field teachers, and those seeking instructional strategies to add to existing repertoires.