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

ABSTRACT

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.

KEYWORDS:

• CoRe
• digital technologies
• PCK
• reflection
• student teacher

Introduction

During the last decades, much attention has been paid to the knowledge and practices underlying effective teacher education programmes. In the context of science education, researchers have emphasised the need to more deeply stimulate student teachers’ reflections indicating that increasing linkages to teaching practice in teacher education is a key concern (e.g. Hanuscin, 2013; Loughran, Berry, & Mulhall, 2006, 2008; Nilsson & Loughran, 2012). Further, to meet student teachers’ learning needs, teacher educators might need a deeper understanding of teacher knowledge in a particular area (e.g. assessment, students’ understanding, and instructional strategies) and how these can be explicitly targeted in the teacher education programme. Therefore, in order to support student teachers’ professional learning, there is a need for more extensive research into the relationship between different elements that constitute teacher knowledge, and how these can be captured and understood.

An important aspect of this study is the role of student teachers’ reflection on their science teaching practices. Schön (1983) used the terms ‘reflection-in-action’ and ‘reflection-on-action’. Reflection-in-action is described as reflecting on the incident whilst it can still benefit that situation rather than reflecting on how you would do things differently in the future. Reflection-on-action involves reflecting on how practice can be developed or changed after the event. ‘We reflect on action, thinking back on what we have done in order to discover how our knowing-in-action may have contributed to an unexpected outcome’ (Schön, 1983, p. 26). As such, reflection-on-action involves thinking back on events whereas reflection-in-action is ‘thinking on your feet’ (Schön, 1983, p. 61).

Building on the idea of ideas of Schön (1983), Park and Oliver (2008) described knowledge-on-action as knowledge elaborated and enacted through ‘reflection-on-action’ and used in planning for and delivery of topic-specific instruction. This knowledge is explicit and can be found, for example in lesson plans, or can be elicited directly from teachers. Through reflection-on-action, the teachers realise the need for expansion or modification of their planning or repertoires for teaching a particular topic. As a result, they make additions to, reorganise, or modify their existing body of knowledge for teaching the topic. What the teacher does in the classroom is informed by knowledge-on-action but also involves instant decision making and therefore requires a more dynamic kind of knowledge called knowledge-in-action (developed and enacted during teaching through ‘reflection-in-action’). Knowledge-in-action is sometimes explicit but is more often tacit and more difficult to capture (Park & Oliver, 2008).

In this study, the former aspect of reflection (reflection-on-action) was stimulated through student teachers’ systematic reflections on video-recorded lessons. Video-recordings have proven to be a valuable tool for capturing teaching episodes, subsequent reflection and development of educational skills (Coffey, 2014). Recent developments in video annotation have the potential of enhancing and augmenting reflective practices based on video-recorded lessons. In a comparative study of potentials for video annotation tools to support and transform teacher reflection, Rich and Hannafin (2009) established that such tools offer the ability to see as well as to analyse and refine teaching practice. Hence, video annotation tools might help to scaffold, structure and even transform a teacheŕs reflection-on-action (Rich & Hannafin, 2009). With this background, the student teachers in this study were encouraged to use a video annotation tool to identify and capture aspects of their own teaching practice that they need to address (i.e. reflection-on-action).

The theoretical background framing this study is teachers’ professional knowledge, which characterises teaching as a complex cognitive skill. Shulman (1986, 1987) introduced the term ‘pedagogical content knowledge’ (PCK) to draw attention to the value of the special amalgam of content knowledge and knowledge of general pedagogy that a teacher needs in order to be the best possible teacher. Various scholars have further developed conceptualisations of PCK (Abell, 2008; Friedrichsen, Driel, & Abell, 2011; Gess-Newsome, 2015; Kind, 2009; Magnusson, Krajcik, & Borko, 1999; Park, Jang, Chen, & Jung, 2011; Rollnick, Bennett, Rhemtula, Dharsey, & Ndlovu, 2008; Van Driel & Berry, 2012) as an academic construct representing specialist knowledge of practice. Several researchers conceptualise PCK by defining its components and reflect PCK as an integration of these components (e.g. Friedrichsen et al., 2011; Padilla & Van Driel, 2011). PCK is ‘the knowledge that teachers bring forward to design and reflect on instruction’ (Gess-Newsome, 2015, p. 36). It is therefore the knowledge that teachers activate when they plan particular lessons on a specific topic or when they reflect upon them afterwards, thus when they undertake, as Schön (1983) described, reflection-on-action. As such, PCK has become a way of understanding the complex relationship between different knowledge components and how these are integrated within the use of specific teaching approaches.

Shulman (1987) noted that reflection and evaluation are recognised as important elements in teachers’ development of PCK. Further, student teachers’ reflection on their own practice paves the way to making decisions about the nature of professional learning that also will improve their practice (Loughran et al., 2006, 2008; Nilsson, 2009). As such, for the purpose of stimulating student teachers’ reflections and developing their PCK, Content Representations (CoRe) (Appendix 1) has shown to be a useful pedagogical tool (Hume & Berry, 2011, 2013; Loughran et al., 2006). The CoRe requires the teacher to reflect upon how to teach a specific topic in order to promote students’ learning. It prompts the teacher to articulate what is called ‘Big Ideas’ relating to queries that include: what students should learn about each big idea; why it is important for students to know these ideas; students’ possible difficulties with learning the ideas; and how these ideas fit in with the knowledge the teacher holds about that content. In this way, working with the CoRe as a reflective tool has the potential of helping teachers conceptualise their professional knowledge and make explicit the different dimensions of, and links between, knowledge of content, teaching, and learning about a particular topic.

Several researchers have used the CoRe as a tool for stimulating reflection and capturing student teachers’ development of PCK. In their work with student teachers, Hume and Berry (2011) discovered that completing a CoRe was challenging and student teachers’ lack of classroom experience proved to be a limiting factor. In spite of this challenge, with appropriate and timely scaffolding, the process of constructing a CoRe helped the student teachers in their PCK development (Hume & Berry, 2011). Further, in her review on PCK, Kind (2009) argued that the CoRe tool offers the most useful technique devised to date in science education research for eliciting and recording the PCK directly from teachers.

This study explores how a group of 24 secondary science student teachers came to understand aspects of their Pedagogical Content Knowledge (PCK) during a five-week school practicum course. The aim of the study was to investigate how CoRe – as a reflective tool in combination with annotated self-recorded videos and reflective writing – might contribute to capture aspects of student teachers’ PCK. Since the development of PCK is to a great extent a result of reflection-on-action, the CoRe was introduced alongside a video annotation tool, allowing for student teachers to locate and comment on critical incidents (Hanuscin, 2013). The student teachers had to locate critical incidents were where they assumed they had either succeeded or failed in their teaching performance in relation to their CoRe’s Big Ideas. In the study it was investigated how the CoRe design prior to teaching episodes might raise student teachers’ awareness of teaching issues around certain content and engage them in reflection and decision-making on their enactment in the classroom. As such, the CoRe, together with video and associated digital tools assisted student teachers in their self-reflective process by making explicit those instances that are critical in relation to their PCK. The research questions that pertain to the data analysis are:

• How can the CoRe design in combination with a video annotation approach be used as a means for capturing student teachers’ professional knowledge of practice?

• What components of PCK are captured and integrated in the student teachers’ reflections?

The answers to these questions are crucial to the pedagogy of teacher education. Hence, the practices and processes highlighted in the project help to inform how to involve student teachers in capturing and developing a professional knowledge base for teaching. In the study, reflection was used as a means of student teachers’ professional learning through interventions of reflective writing where student teachers were asked to evaluate their own learning in relation to the CoRe. From the perspective of sociocultural theory (Vygotsky, 1978), knowledge is essentially understood as an ever-changing product in a process from social to personal knowledge and the knowledge development is bound to a specific context. The CoRe design prior to teaching episodes raises student teachers’ awareness of teaching issues around certain content and engages them in the pedagogical reasoning and decision-making that they enact in the specific classroom context.

Conceptualising PCK

In order to draw attention to the value of the special amalgam of content knowledge and knowledge of general pedagogy that a teacher needs to promote students’ understanding, Shulman (1986, 1987) introduced the term pedagogical content knowledge (PCK). Shulman (1987) described PCK as representing ‘the blending of content and pedagogy into an understanding of how particular topics, problems, or issues are organised, represented, and adapted to the diverse interests and abilities of learners, and presented for instruction’ (p. 8). Among researchers, there is a common assumption that a high level of PCK will predict a high level of student achievement (e.g. Rollnick et al., 2008), and some researchers (e.g. Baumert et al., 2010) stress that PCK makes the greatest contribution to explaining student progress. Teachers need to understand what students already know about a topic, what those students are likely to have difficulties with learning the topic, and what concepts need to be challenged (Park et al., 2011). Several researchers have further conceptualised PCK by defining its components and reflect PCK as an integration of these components (e.g. Friedrichsen et al., 2011; Nilsson & Vikström, 2015; Padilla & Van Driel, 2011). Similarly, Park and Chen (2012) explored the integration among PCK components focusing on the frequency of connections among them. Magnusson et al. (1999) argued that there is a multifaceted relation between the components of PCK and for being an effective teacher; having a solid knowledge of only one component is not adequate. As such it might be suggested that integration is the key functional term that underlies PCK, pointing out that different components of PCK must be learned and applied simultaneously, but not necessarily in equal parts in every learning experience (Nilsson & Vikström, 2015).

To reach some level of agreement regarding the various conceptualizations of PCK, in 2013 a group of researchers explored a model of teacher professional knowledge and skills including PCK: the ‘PCK Summit Consensus Model’ (Gess-Newsome, 2015, p. 31). The model (fig. 1) illustrates the connection between teacher knowledge for teaching as a profession, their actual classroom teaching and the student outcomes. The model elaborates on what the teacher knows and how this knowledge comes into the classroom with significant influence on the students’ understandings. Within the first stage in the ‘teacher professional knowledge bases’ model are the various teacher knowledge components: the assessment knowledge, pedagogical knowledge, content knowledge, knowledge of students and curricular knowledge (Gess-Newsome, 2015). This stage is linked to the classroom practice and student outcomes. The second stage of the consensus PCK model is described as ‘Topic Specific Professional Knowledge’ (TSPK), comprising the knowledge of instructional strategies, content representations, student understandings, science practices and habits of mind (Gess-Newsome, 2015).

Figure 1. The ‘PCK Summit Consensus Model’ (Gess-Newsome, 2015, p. 31).

In the model, personal PCK is ‘the knowledge of, reasoning behind, planning for, and enactment of teaching a particular topic in a particular way for a particular reason to particular students for enhanced student outcomes (refection-on-action)’. Personal knowledge and skills (PCK&S) is ‘the act of teaching a particular topic in a particular way for a particular reason to particular students for enhanced student outcomes reflection-in-action’ (Gess-Newsome, 2015, p. 36). Both these definitions are closely related to this particular study, where a central objective of the student teachers’ school practicum is to encourage them to reflect on their own teaching in relation to their teaching subject. Many student teachers find this reflective process difficult, implying a demand for more informed structures about how to perform a constructive reflective practice of one’s own teaching (Parsons & Stephenson, 2005). In lack of a structured procedure, student teachers in their reflections often tend to describe what they have done, rather than to reflect on pedagogical issues, which involve identifying reasons for success or failure, and as a consequence fail to suggest appropriate actions.

In the PCK research literature, Magnusson et al. s’ model (1999) is commonly used as a way to analyse and capture teachers’ PCK. In the model, PCK consists of four knowledge components: knowledge of science curricula, knowledge of students’ understanding of science, knowledge of assessment of scientific literacy and knowledge of instructional strategies. Knowledge of students’ understanding of science is related to learners’ difficulties and misconceptions in learning specific topics and requires knowledge necessary to learn the topic. Knowledge of science curricula consists of knowledge of curriculum goals, and of curricular materials provided by the curriculum developers. Knowledge of assessment of scientific literacy comprises knowledge of what and how to assess students’ learning. Knowledge of instructional strategies involves knowledge of activities (such as simulations, demonstrations and experiments) and representations (such as analogies, models, illustration and examples). Research has indicated that knowledge of student understanding and knowledge of instructional strategies and representations are the most important for student learning (Berry, Friedrichsen, & Loughran, 2015; Nilsson, 2014; Park & Chen, 2012). Further, as Park and Chen (2012) noted, the interaction and coherence among the PCK components are more critical to its quality and development than the strength of individual components.

In this particular study we used three out of the four knowledge components of the model of Magnusson et al. (1999) to analyse aspects of student teachers’ PCK that were captured and integrated within their reflections on their teaching actions. The three knowledge components we used were knowledge of students’ understanding of science, knowledge of assessment of scientific literacy and knowledge of instructional strategies. Since science curricula was the basis for the student teachers’ planning of their teaching and rarely expressed explicitly, we have not included this knowledge base in our analysis. To tighten the format in the analysis and result section we have used the abbreviations KSU, KA and KIS.

Capturing PCK through reflection on critical incidents

Hanuscin (2013) noted that by using scenarios that are rooted in classroom experience, student teachers’ learning of how to teach is fostered through discussion and reflection on critical incidents: ‘Growth in one’s knowledge for teaching comes about when reflection on critical incidents involves challenge to and critique of one’s self and professional values, which in turn can lead to changes in practice’ (p. 937). Tripp’s (1993) notion of critical incidents is that they arise in practice from the way teachers look at a situation and interpret its significance. Critical incidents could have successful or unsuccessful outcomes, indicating that the analysis of their consequences for practice is equally important. Amade-Escot (2005) argued that focusing on critical incidents when teaching a specific subject matter, demonstrating failure or success, is a tool that invites us to take the development of content more into consideration and to better understand the functioning of a teaching and learning activity.

In this study, to help the student teachers to analyse their teaching performance, they were requested to direct their attention to ‘critical incidents’ where they thought they had either failed or succeeded in their teaching in relation to their CoRe. Helping student teachers to identify critical incidents that shape their PCK might support them in their learning to teach, develop their reflective and critical thinking skills and contribute to new insights into their professional development (Farrell, 2008; Griffin, 2003; Hanuscin, 2013). However, for a self-reflecting process to be fruitful it is important that the student teacher is aware of the pedagogical theories underlying his or her own thinking. Hence, a conceptual framework that includes the student teachers’ pedagogical thinking with the actual teaching practices (for example, PCK) would therefore be beneficial for a constructive self-reflecting process. When student teachers are encouraged to analyse their own teaching practice in order to better understand what, why and how they do it, they may also become more empowered to seek new ways of conceptualising their practice. By encouraging student teachers to focus on critical incidents, it is anticipated that they might question their practice more deeply and begin to see into the challenging nature of teaching (Nilsson & Loughran, 2012).

Video and annotation practice

In her longitudinal study, Harlin (2014) examined whether student teachers’ reflection on video data actually resulted in changed teaching habits after a two-year period as practicing teachers. As a result of video-enabled reflections providing the opportunity to draw attention to aspects that they had not noted from memory alone, the student teachers had either applied new habits or developed previous habits (Harlin, 2014). For coping with the challenges of using video as a reflecting tool in teacher education, Miller and Zhou (2007) emphasised the role of instructional strategies that offer guidance for the viewers and specify which learning goals will be reached by the video analysis. When using video as an instructional strategy in teacher education, it is therefore important that the learning goal and purpose of the course in question should determine which instructional strategy should be employed (Blomberg, Sherin, Renkl, Glogger, & Seidel, 2014). In a strategy for self-reflecting practice where student teachers constructed video cases about their own teaching, Rosaen et al. (2009) found that student teachers did not seem to connect their performance to their specific subject-matter goals. Therefore, a guiding framework is considered crucial for student teachers to make systematic and in-depth self-reflection on their teaching performance (for example, Kong, Shroff, & Hung, 2009; Parsons & Stephenson, 2005). Such a guiding framework might assist in their self-reflective process by serving as a scaffold for making explicit those instances that are critical in relation to their pedagogical content knowledge (PCK). Further, written reflections on video-recorded teaching episodes make it possible to engage in dialogue with a tutor and to advance the process of self-reflection (Coffey, 2014). As claimed by Coffey (2014), this strategy would be particularly useful in teacher educational programmes where student teachers develop their teaching skills in a shorter time period than what is considered normal. It is not enough just to provide opportunities for student teachers to develop their reflection skills. Instead, such opportunities need to be very purposeful in order to facilitate the development of these skills.

Study design

This project is designed around a group of 24 secondary science student teachers following an 18-month period of teacher education programme of educational science, science education and teaching practicum. Before entering the programme, all student teachers had at least two years of studies in one or two science subjects. By the time of the study, the student teachers were in their last semester, following a five-week school practicum where they should develop their PCK for teaching science in the secondary classroom. As noted by Yerrick, Ross, and Molebash (2005), without careful guidance the student teachers might not know what to reflect upon when viewing their video, and hence, will refer to factors that are not directed at the focus of the teacher education programme. Therefore, in order to make the student teachers’ video-enabled self-reflection focused on significant aspects of PCK, the CoRe was introduced to the student teachers as a tool meant to capture aspects of PCK within their planning, teaching and reflection. In addition to the CoRe, the student teachers were introduced to a video annotation tool to support their self-reflection by locating and making evident such instances that can be seen as critical in a teaching sequence. This tool was used to scaffold and structure the student teachers’ reflection-on-action. In the beginning of the course, all 24 student teachers were provided with iPads in order to video record at least one lesson during their practicum. The course was introduced at the university, with an introduction of a CoRe, what components of PCK the CoRe prompts refer to, how to practice this reflective tool and its potential for capturing components of PCK. They were also instructed on how to use the video-based method for self-reflection and communication. Further, the student teachers were informed of the research project, that participation was voluntary and that they were not graded on their reflections. All student teachers agreed to share their reflections in the research project, and informed consent was obtained from all participants.

During their practicum, the student teachers were encouraged to set up a CoRe for a chosen topic. They then had to video record at least one of their lessons when teaching this topic. The video recordings were uploaded on YouTube as a private video clip. YouTube was used since we considered it the most expedient software for our purposes (user friendly, easily accessible, free of charge, well known and hence needing no further instruction for use). YouTube also provides an annotation tool, which is adequate enough for the need of making annotations of critical incidents. Using YouTube for educational purposes involves legal and ethical concerns (Snelson, Rice, & Wyzard, 2012); however, uploading a video as a private clip ensured that it was exclusively observable to the individual student teacher and the teacher educators (researchers).

The student teachers were then encouraged to reflect upon their teaching performance to identify critical incidents in relation to their CoRe that had occurred during the video-recorded lessons. They had to choose two teaching episodes each of about 4–8 min, representing: 1) a critical incident where they thought they had succeeded in accordance with the Big Ideas in their CoRe; and 2) a critical incident where they had found difficulties in fulfilling their ambitions expressed in the CoRe. Having identified these critical incidents, the student teachers had to make annotations in the videos, pinpointing these two critical incidents. The annotations in the video should be a short description of what they wanted to focus on in this particular incident (for an example, see Fig. 1). The annotated critical incident had to be elaborated on in a written account, where they had to argue the following:

1. What is happening in the incident?

2. Why have they chosen this particular moment?

3. Why is this a critical incident in regard to their CoRe?

4. What consequences can they see for future teaching actions?

As such, the study was designed in a way that stimulated student teachers’ ‘reflection-on-action’ used in the planning for and teaching of a specific topic. The annotated video clips, together with their written reports, were then sent to the teacher educators (researchers) for their comments.

Data analysis

The annotated video clips and the written reflection of each critical incident were transcribed and used as data for further analysis for each of the 24 student teachers. The analysis was then completed in two stages. In the first stage, the two authors independently identified episodes within data that indicated how the CoRe in combination with the annotated video helped to capture components of student teachers’ PCK. The episodes formed the basis for the vignettes. The episodes were compared between the two authors and any disagreement were discussed until a consensus was reached.

In the second stage, the identified episodes were analysed through qualitative content analysis, QCA (Schreier, 2014), which is ‘systematic, flexible and reduces data’ (p. 5) and which limits the analysis to ‘those aspects that are relevant with a view to your research questions’ (p 7). In this part of the analysis we used the three knowledge components of Magnusson et al. (1999). Therefore, we probed for instances within the episodes that captured their knowledge of students’ understandings (KSU), knowledge of instructional strategies (KIS) and knowledge of assessment (KA), and further, how these three components were (or were not) integrated. In such way, vignettes that indicated both the different knowledge components (KSU, KIS and KA) and how they were integrated within student teachers’ reflections-on-action were created. From the material of the 24 student teachers, we chose four student teachers’ reflections to be illustrated in the result. These four data sets were chosen because we found them as representative examples of our analysis. The vignettes comprise detailed descriptions of the instructional strategies used and the student teachers’ reflections on incidents within the teaching that were considered successful or less successful in relation to their CoRe.

Corrigan and Loughran (2007) describe vignettes as short stories that capture critical incidents/events and processes that comprise elements of the teaching as experienced by the student teachers. They are written in a form that is intended to create opportunities for the reader to reflect on the events in order to extract new learning and reconsider the situation(s) in new ways. Four vignettes of student teachers’ reflections are presented below. The vignettes intend to document the student teachers’ reconstructed thought processes, providing a window into their reflection-on-action associated with teaching a science concept planned through the CoRe. Each teaching vignette comprises quotes expressing the student teachers’ pedagogical reasoning underlying his/her teaching of the chosen topics. Following a method similar to that of Park and Chen (2012), a PCK figure was constructed for each student teacher described in the vignettes (appendix 2-9). These PCK figures are constructed from the complete data for each student teacher and summarise the course of events, including evidence of PCK components and how these were integrated within the student teacher’s reflections. As such, the figures intend to visualise the identified PCK-components and how these are integrated within the student teachers’ reflections.

Findings

Examples of the findings are presented below as four vignettes comprising descriptions of what kind of critical incidents the student teachers identified, and how these incidents were related to their Big Ideas in their CoRes. Each vignette is accompanied by a PCK figure (appendix 2-9) outlining the main actions in their reflective work and how they relate to components of PCK. Thus, the vignettes and figures make visible the links and interrelations between (1) the processes of reflection on-action, (2) reflection in relation to CoRe, (3) consequences for further teaching and (4) relations to components of PCK.

Vignette 1, Sonja

Sonja teaches a group of students in year nine (15-year olds) about protein synthesis and heredity. Even if it is not explicitly stated in the curriculum that students should know about protein synthesis (expressed in Big Idea C in her CoRe), Sonja considers that an understanding of DNA and proteins, and how they interact in protein synthesis, will make it easier for her students to see how links between mutations and genetic changes might lead to changes in the human body.

Sonja: I hope that an understanding of the various tasks of DNA and proteins and how closely connected they are will facilitate the understanding of evolution. It will be easier for the students to see clear links between mutations and genetic changes that lead to changes in bodily functions and appearance. On the other hand, it is not explicitly formulated in the biology syllabus that students need to understand the Big Idea C. However, it is explicitly stated in the syllabus that heredity should be taught. I had a big dilemma when I planned this lesson. Either I should spend time for students to build a deeper understanding and have less time to explain the mechanisms of heredity, or I could skip Big Idea C and have more time to practice those aspects that are indicated in the curriculum.

The question Sonja asks herself here is whether she should direct her instruction towards protein synthesis (Big Idea C), and as such, use less time to explain the mechanisms of heredity, or if she should spend more time explaining heredity as stated in the curriculum. In her reflection, different PCK components are integrated. Sonja considers that an understanding of protein synthesis will facilitate students’ understanding (KSU) of a specific science topic. This idea conflicts somewhat with the time she has at her disposal and with what is stated in the national curriculum. These insights lead her to (re)consider her instructional strategy. As such, her KSU and KIS are interconnected in a way that enables her to transform content knowledge into instructional activities from a more holistic perspective.

A successful incident (PCK figure in appendix 2)

Sonja teaches about how information is transferred from a gene to a complete protein. In her reflection, Sonja describes how she fully succeeds by following a formative teaching method in which she manages to transform the knowledge in a way that her students understand.

Sonja: I start the sequence by examining students’ prior knowledge. I asked them to summarize what they already knew about the processes, that is, what we have learned in the previous lesson. Their summary indicates that they understand that a gene contains information on how a protein is built up, but they cannot explain the process in detail. […] After this I explain clearly how it all fits together. I draw pictures on the whiteboard and I keep to my descriptions in the CoRe (Big Idea C). I clarify each step of the process and avoid difficult concepts and subject areas that I, in my CoRe, have identified as being challenging for the students. I point out that DNA never leaves the nucleus, but that there are DNA-like molecules that do, i.e. RNA. I also point out that there are proteins that read the DNA and build other proteins and it is the order of the nitrogen base pairs that contains the actual information about the amino acid sequence. In this way, I try to link Big Idea C with Big Ideas A and B.

In this vignette, it is indicated how Sonja uses formative assessment (KA) to ascertain her students’ understanding, and from this she outlines her instruction (KIS). Thus, Sonja uses her knowledge of assessment (KA) to evaluate students’ understanding (KSU), which in turn directs her instructional strategy. Components of PCK are interconnected and support each other within the interaction in the classroom. The quote also demonstrates how Sonjás CoRe helps to connect her teaching to the content of the earlier lesson and build on students’ prior knowledge. As such, the process of interactions between components of PCK that takes place between Sonja and her students within the teaching context is used to make the content more comprehensible for learners.

A less successful incident (PCK figure in appendix 3)

The next step in Sonja’s lesson plan is to make her students understand how heredity works (as described in her Big Idea B). The less successful incident Sonja identifies is when at the end of the lesson she realises that she has not devoted enough time to explain heredity, and that a clarification is needed:

Sonja: Thus, I had not focused enough on the predicted difficulties students may have with Big Idea B. On the other hand, I let the students practice on different exercises that cover Big Idea B, but here I feel that the time is not enough. However, when I discuss with the students I make sure that they at least understand some parts of Big Idea B, but I cannot keep up with all the students and do not have time to check all responses. This means that I must take up Big Idea B and repeat these exercises in the next lesson. I need to repeat the main concepts according to the Big Ideas and make sure they understand how a crossover schedule works before we go on to discuss the following topics, such as evolution. On this occasion, I will again make clear that each gene comes in two sets available on each chromosome pair.

Sonja now realises her students’ difficulties in understanding how heredity works, described in her Big Idea B. When discussing with the students, she uses her knowledge of assessment (KA) to assess her students’ understanding of the topic. Consequently, she recognises the need for repeating the main concepts and considers another strategy for teaching heredity in the next lesson. Thus, her CoRe provides her with a tool against which she can assess her students’ understanding, as well as a tool for considering which concepts should be repeated to promote students’ understanding and how her instruction will be structured to meet their learning needs (KIS).

Vignette 2, Olaf

Olaf’s video-recorded sequence is from a lesson where he teaches about the Big Bang theory as an explanation for an expanding universe. In his CoRe (Big Idea D), he has stated that knowledge about the Big Bang theory is essential for students’ understanding of an expanding universe. He remarks that the curriculum emphasises that students should learn about the expansion of the universe. In the video, Olaf first demonstrates to students that distant galaxies are moving away from the Earth. He then illustrates that galaxies can move away from each other without having a central point. In his second instruction he considers himself to be successful, whereas he thinks he found less success in the first part.

A successful incident (PCK figure in appendix 4)

In this incident, Olaf illustrates that galaxies can move away from each other without there being a central point. He has marked a balloon with two dots, and when he blows up the balloon the students can see how the two dots distance themselves from each other. He then asks the students several control questions, from which he gets positive answers. He also receives some questions from his students about his demonstration that are connected to the expansion of the universe. This is something that he highlights as being successful in relation to his intentions in the CoRe.

Olaf: I chose this situation because I felt that it led to that the pieces of the puzzle fell into place for the students. I think it is good to combine verbal explanations with demonstrations. Some things are more difficult to express with words and different ways of is needed for different students.

From the responses, Olof receives from his students he feels that they have reached an understanding of the concept. He supposes it can be attributed to his demonstration with the balloon and surmises that verbal explanation, together with a demonstration, enhances students’ understanding. Olaf’s reflection on his instructional strategy (KIS) is closely linked to his reflection on students’ understanding (KSU). Students’ understanding also played a major role when he designed his CoRe:

Olaf: It was important that I had considered the difficulties and misunderstandings that students could have when I designed my CoRe. This made me prepare the demonstration thoroughly. The result was that most students expressed that they understood how the expansion occurred and how this was related to the Big Bang.

Thus, Olaf’s creation of his CoRe helped him in considering students’ understanding (KSU) of the topic, as well as in preparing his instructional strategy (KIS).

A less successful incident (PCK figure in appendix 5)

In this incident, Olaf explains that the fact that distant galaxies are moving away from us more quickly than nearby galaxies is proof of the Big Bang theory. He uses the whiteboard, where he draws the Earth in the middle, with galaxies and stars distributed around it. He then draws arrows and explains that the ones farthest from the Earth move at a higher speed away from the Earth then those that are closer to the Earth. He asks his students if they have understood, but he receives a negative response from one of his students. In response to why this was a critical incident in relation to his CoRe, he writes:

Olaf: I chose this situation because I felt that it was confusing when I drew the Earth in the centre. As my CoRe planning shows, many students have difficulties with grasping that the universe does not have a centre. To illustrate this, I should have used the demonstration with the balloon. I felt that some students were a bit confused but at the same time I thought that a demonstration with the balloon would probably have answered these questions.

In his CoRe, Olaf ascertained his students’ difficulties with understanding (KU) this concept. He realises that his instruction was confusing for the students and considers another instructional strategy (KIS). He draws on his earlier experience with the demonstration with the balloon. As such, his experiences from the lesson provided him with new insights in a way that helped him reconsider his instructional strategies (KIS).

Vignette 3, Ann

Ann is teaching students in their fifth year (11-year olds) about memory. According to her CoRe, Ann wants her students to understand how memory works and how it consists of both short-term and long-term memory. She remarks that her students often show great interest in her lessons and that they happily want to discuss their own experiences. As Ann thinks that building on students’ everyday experiences contributes to their engagement and motivation to learn about a topic.

A successful incident (PCK figure in appendix 6)

In this sequence, Ann explains the function of our long-term memory. A student asks if a person remembers something better if it is something important. Ann answers by using a context-based example: if a new sibling is born, this would be an important event that makes it easier to remember. By answering the student's question she has the opportunity to describe that a person remembers things better if it is considered important and if it is connected with a pattern or a context. Ann reflects that this incident is important in relation to her CoRe:

Ann: It shows the advantages of teaching methods with an initial presentation as described in the CoRe. You do not always know what associations or reflections students will make in a particular context. Here I had a PowerPoint slide that illustrated that it is easier to remember something when it is linked to a familiar pattern or context. The question I received and the way I answered it gave me the opportunity to discuss how our long-term memory works. I also believe that the situation contributed to the students’ understanding of how our long-term memory functions (as expressed as an intention in my CoRe).

This method of building her teaching on students’ responses is something that Ann intends to use in her teaching:

Ann: The consequence of the event is that I increasingly will try to elicit questions from students and build shared reflections on these (insofar they are in line with the topic for the lesson).

Here Ann describes how she applied the instructional strategy (KIS) outlined in her CoRe, which was to elicit questions from her students in order to build on them in her teaching. She receives a question from one of her students, which enables her to exemplify how our memory functions. Ann believes that this method contributed to her students’ understanding of the topic (KSU). Anńs instructional strategy, outlined in her CoRe, facilitates her intention to support her students’ understanding of the topic. As such, her KSU and her KIS are strongly connected.

A less successful incidence (PCK figure in appendix 7)

In this sequence, Ann tells her students that old people sometimes have a failing short-term memory. As a consequence, her students provide her with several stories about elderly relatives who do not remember their children, grandchildren and even a spouse. Ann reflects on this event as less successful:

Ann: I chose this event because I thought it clearly showed a situation where I did not achieve my goals according to my CoRe. It did not lead to the students having a better understanding of the difference between the short-term and the long-term memory. It became quite unclear what is meant by an impaired short-term memory when I instead had to comment on elderly people who had forgotten about important life events like their own children. I lost the situation and did not come back to what I had intended to talk about. I also chose this incident because similar situations can occur at times, and I want to reflect on how I can prevent this from happening.

About the consequences for her further teaching, Ann reflects that:

Ann: I will be aware of similar situations in the future and ensure that I stick to the main purpose of the lesson. If a similar situation should occur and if we deviate from the topic, I will raise this in retrospect and clarify the issue.

In both the successful and less successful incidents, Ann refers to the same Big Idea in her CoRe, namely her ambition to involve her students in a discussion about the topic at hand, and thereby eliciting examples from students’ everyday experiences. In the successful incident, this instructional strategy led to her being able to elaborate on a student’s question, clarify the issue at hand and facilitate students’ understanding. In the less successful event, the students’ questions led to a distraction from the topic, which helped Ann to reconsider and be more cautious about her instructional strategy (KIS).

Vignette 4, Sophie

Sophie teaches a group of students ranging from 13 to 15 years of age. The lesson is about fermentation and involves two parts. First, there is a discussion about the fermentation of dough, which is inspired by a ‘concept cartoon’. Then there is a systematic experiment with yeast in different sugar solutions with a control test.

A successful incident (PCK figure in appendix 8)

In the second part of Sophiés lesson, in which the students are to perform an experiment with yeast, Sophie thinks she manages to reach her goal in her CoRe. Sophie’s intention with the experiment is to show the importance of conducting a systematic investigation and of having a control test. The experiment is achieved by mixing the same amount of yeast with different sugar solutions in separate test tubes. A tube containing only the sugar solution constitutes a control sample. Then the students have to put balloons on the tubes and place them in a water bath. After about 20 min they will be able to observe potential expansions of the balloons.

Sophie reflects that:

Sophie: I chose this sequence because I think I managed to explain why it is important to have a control sample when carrying out a test. As I expressed in my CoRe, I wanted my students to understand why it is important to have a control sample in order to do a test where you can draw a conclusion from the result. This is an important incident. I also wrote in my CoRe that the students did not have much experience from experimenting. It was also noticeable that, as I feared, it became rather noisy and several students had difficulties with handling the equipment. Despite this, all groups had an equal amount of liquid in their tubes and all of them made use of a control sample. Many students also asked questions in order to check if they had got it right. So … my explanation must have worked for most of the students.

In her CoRe, Sophie had anticipated the students’ inexperience with laboratory work and hence, she had instructed her students carefully. Sophie is satisfied with the outcome of her instruction, since all students conducted the experiment as intended and several of them also asked questions to ascertain that they had understood. Thus, her CoRe helped her to recognise the students’ understandings (KSU) and to adapt her instructional strategy (KIS) accordingly. Sophie assesses her students’ understanding by observing how they perform the experiment and by asking questions (KA). Thus, her CoRe helped her to identify the students’ weakness and to allow her to adapt her instruction accordingly. Sophie stresses the importance of a control sample, which is an issue that she will raise whenever she runs experiments with her students.

A less successful incident (PCK figure in appendix 9)

The less successful incident occurs in the first part of the lesson, in which Sophie wants her students to discuss, in groups, a ‘concept cartoon’. The ‘concept carton’ consists of a drawing intended for inspiring a discussion among students about the fermentation of dough. The drawing shows four children and a loaf of bread. A question that accompanies the drawing says ‘Why does the dough become larger after a while?’ In response to this question, her students put forward different ideas and opinions based on their common everyday concepts. Sophie then asks her students to discuss their ideas in groups and then describe their views to the others in the class. Sophie reflects on the incident:

Sophie: I chose this moment because it was the first time I used a ‘concept cartoon’ in this class and I dońt think I succeeded so well. The discussion came to be about other things than was intended and I felt that I did not reach the learning goal as expressed in my CoRe. […] My intention was to elaborate on the students’ discussions and that we together should reach the scientific explanation that yeast produces gas that makes the dough swell. However, we did not come that far and I felt that it was better to end the discussion and move on to the experiment. Instead I raised the issue again after they had performed their experiment and then explained what had happened and why.

Sophiés intention according to her CoRe – to elicit a discussion about fermentation – did not work out as she had planned. The discussion turned to other things. This insight about her students’ understanding (KU) made her change her instructional strategy (KIS) and continue with the next part, which was the experiment. In summary, the examples from the four vignettes above indicate how the student teachers came to see aspects within their teaching practice that could be identified as components of PCK. In the vignettes, PCK is expressed as a process of interactions between components of PCK that take place between the student teachers and their students within the teaching context. Further, the vignettes indicate that PCK components interact in a variety of sophisticated ways when used in teaching a topic.

Discussion

This study investigated how CoRe – as a reflective tool in combination with annotated self-recorded videos and reflective writing might contribute to capture aspects of student teachers’ PCK through a process of planning-teaching and reflecting on science lessons. The findings illustrate that a CoRe design prior to teaching episodes help student teachers to focus attention on the teaching of certain content and engage them in reflection-on-action and decision-making concerning their planning for teaching a particular topic for particular students. The video-recording of these teaching episodes with its annotative function allows each student teacher to review themselves in action, identify critical incidents that they believe impact on their professional development, reflect on the nature and extent of that impact, and identify future actions that builds on this professional learning.

This study indicates that having student teachers explicitly articulate their reasoning at three key points of a plan-teach-reflect cycle seems important for a) describing the types of knowledge used in these teaching practices and b) observing how student teachers reflect on aspects of their teaching likely to influence their PCK. Practically, the CoRe seems to provide a fruitful framework for supporting student teachers’ reflection. Also, Loughran and his colleagues (2004) noted that when science teachers begin to ‘unpack’ their content knowledge through CoRes, it helps them to focus on what matters in a content area and to teach in ways that have a clear purpose and focus. This unpacking process helps teachers to develop a conceptualisation of the subject area, both for themselves and for their students.

In response to the call for research into examining the integration of PCK components (Park & Chen, 2012), we sought to explore how the use of the CoRe, together with video annotations in conjunction with written reflections on critical incidents, can stimulate the student teachers’ capacity to reflect on their teaching skills in an integrated manner. The different tools enabled 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’ reflections, and consequently contributed to capture aspects of their PCK, important for their learning to teach science. Therefore, the results support the claims that different forms of systematic reflections can both capture the PCK components and allow student teachers to articulate connections between these components. As Park and Chen (2012) noted: ‘Given the integrative aspect and complexity of PCK, however, to provide insightful implications for practice, it is necessary to investigate how all components interact with one another and how they are integrated into PCK that enables a teacher to transform content knowledge into instructional events from a more holistic perspective’ (p. 923).

Although PCK has been studied for more than 25 years, only a few studies have investigated how different PCK components are integrated (Abell, 2008; Friedrichsen et al., 2011; Park & Chen, 2012). Therefore, this particular study does not focus only on the PCK components as separate knowledge bases, but also on how the PCK components are integrated within student teachers’ reflections. Abell (2008) noted that the synergistic interplay among the components of PCK is contributing to the quality of the construct. Meanwhile, to capture teachers’ PCK, research suggests that the interactions among PCK components should receive more attention than each of the components in isolation (Abell, 2008; Park & Oliver, 2008). This is because the changes in any one component may become insufficient to affect the change in the entire construct of PCK (Park & Chen, 2012). The interaction between the PCK components is more critical to its quality and development than the strength of individual components (Magnusson et al., 1999; Park & Chen, 2012). As indicated in the study, the student teachers’ knowledge-on-action was captured through their reflections in their CoRe, their planning and their teaching of a particular science content. Through their reflection-on-action, the student teachers identified the need for expansion or modification of their planning for and teaching of a particular science content. As a result, they identified aspects within their teaching that they needed to reorganise, made additions to, or modify to better meet students’ learning needs (i.e. enhanced student teachers’ overall PCK). On the other hand, PCK for effective teaching is the integration of all PCK components in highly complex ways – ‘Thus, lack of coherence among the components would be problematic within an individual’s developing PCK and increased knowledge of a single component may not be sufficient to stimulate change in practice’ (Park & Oliver, 2008, p. 264). A better understanding of how components of PCK are integrated might provide useful information for the design and quality of teacher education programmes.

As indicated in the vignettes, the student teachers provided rich examples of the complex relationship between pedagogy and content captured through the interactions between PCK components. The vignettes indicated student teachers’ reflections in ways that are centred on students and their learning needs, while still self-reflective and thoughtful about implications for the student teachers’ professional growth. As such, the different components of PCK, as well as the dynamic integration between different components, raise important outcomes for teacher education. To better prepare student teachers to develop and grow as science teachers in the future, teacher educators’ understanding of the components of PCK and how they are integrated is important in science teacher education. Besides courses in which pre-service teachers acquire content knowledge as well as knowledge of students’ understandings (KSU), knowledge of curriculum (KC), knowledge of instructional strategies (KIS) and knowledge of assessment (KA) separately, student teachers should also have the opportunity to apply the interplay between the knowledge components in practical situations.

To end, as the CoRe stimulates student teachers’ thinking about science topics through Big Ideas, they focus attention to the role of content in a structured way. Using CoRe as tool for planning lessons on particular topics, combined with video-stimulated reflection-on-action is helpful in supporting student teachers to articulate and discuss their understandings of teaching and learning science topics and enhancing their professional knowledge of practice.

Disclosure statement

No potential conflict of interest was reported by the authors.

ORCID

Pernilla Nilsson http://orcid.org/0000-0001-5283-7038

Göran Karlsson http://orcid.org/0000-0003-2545-7747

Appendices

Appendix 1

Sonja’s CoRe

Table

Content: Protein synthesis and heredity Age of students: 15	Big Idea A	Big Idea B	Big Idea C
What do you intend students to learn about this idea?	Two different cell division mechanisms. In the reproductive cell division, the chromosomes of the mother and the father are crossed; i.e. DNA bits are replaced. In this way, the genes are mixed from the parents, which leads to the child being unique.	Heredity. Every person gets genes from mom and dad. These genes can be dominant or recessive. Dominant genes take over the recessive ones, while they need to be two for the individual to get the recessive properties.	That DNA information is translated into RNA. DNA never leaves the nucleus. RNA moves from the cell nucleus to ribosomes. In the ribosomes the information are translated from the RNA and translated into amino acid sequences, thus building up the proteins.
Why it is important for students to know this?	They need to have an understanding of how DNA is transferred during reproduction to provide crossing schemes.	To understand how we inherit some genes. It creates interest in genetic engineering. It's often on national tests, which they will take soon. It is explicitly stated in the biology syllabus.	To understand how the information in the cell nucleus is interpreted and transferred.
What else do you know about this idea (that you do not intend students to know yet)?	Details about the cell division; i.e. all different phases of mitosis and meiosis. Why two daughter cells are formed in mitosis and four in meiosis?	For many genes it is not easy to predict whether they are recessive or dominant. That many genes/proteins interact with each other, affecting the expression and functions.	Concepts such as replication, transcription and translation. All small steps in these processes. That it is protein complexes that complete the functions, and not proteins. That ER also plays a major part in the translation.
What difficulties/limitations are connected with teaching this idea?	If the students want to understand why recombination of chromosomes occurs. If the students want to understand the details of the cell division, then the explanation becomes very complicated.	That both mom and dad have two sets of the same gene, which means that a progeny can inherit in two different ways from their dad and two different ways from their mother. This means that there are four different combinations of the gene set that the offspring can obtain.	This is a very complicated and long chain of mechanisms in the cell. It is easy to go into details and lose a general understanding.
What difficulties/limitations are connected with teaching this idea?	They have already studied cell division and the reproductive organs in previous years.	They are aware that eye colour is a hereditary characteristic. They also know that the environment plays a major role in how characteristics are expressed.	That DNA leaves the cell nucleus. That they do not know what RNA is and how it is related to DNA.
What other factors influence your teaching of this idea?	I think they remember this from previous lessons. I can expect them to remember more than they are doing, which can lead me to go through this area excessively quickly.	That I know too much about gene interaction (I have a PhD in this area) and lose my focus from the main goal of making them understand a crossing schedule. Shortage of time.	That I've been a researcher in this area and that I think it's really interesting. I can find it difficult to delimit and clarify complex mechanisms.
What teaching procedures will you use and what are the particular reasons for using these to engage with this idea?	Explanation with the help of pictures and discussions.	Exercises with whole class and then individually.	Drawing sketches on the board and ask students to summarise.
What specific ways do you have of ascertaining students’ understanding or confusion?	First, I ask my students what they remember from last year. Then we discuss it. Lastly, they may show the thumbs up, horizontally or downwards, depending on whether they understand.	I move around the classroom and help them to start. I look at their exercises. We will also do more exercises the next lesson.	I ask individual students to summarise what I have told them.

Appendix 2

Incident where Sonja thinks she succeeded

Appendix 3

Incident where Sonja thinks she failed

Appendix 4

Incident where Olof thinks he succeeded

Appendix 5

Incident where Olof thinks he failed

Appendix 6

Incident where Ann thinks she succeeded

Appendix 7

Incident where Ann thinks she failed

Appendix 8

Incident where Sophie thinks she succeeded

Appendix 9

Incident where Sophie thinks she failed