Research in Science Education 31: 289–307, 2001.© 2001 Kluwer Academic Publishers. Printed in the Netherlands.

Documenting Science Teachers’ Pedagogical Content KnowledgeThrough PaP-eRs

John Loughran, Philippa Milroy, Amanda Berry, Richard Gunstoneand Pamela MulhallMonash University

Abstract

This paper examines science teachers’ pedagogical content knowledge and ways in which that knowl-edge might be captured, articulated and portrayed to others. The research from which this paper isdrawn has involved interviews with experienced science teachers in an attempt to make the tacitnature of their practice explicit. Initially, case methodology was envisaged as being a way of docu-menting these teachers’ pedagogical content knowledge. However, over time, the form of knowledgeand information that we were gathering and attempting to portray extended beyond that which couldreasonably be described as being case-based. Hence we have developed an approach to articulationand portrayal based on what we call the CoRe (Content Representation) – which represents the par-ticular content/topic of the science teaching – and PaP-eRs (Pedagogical and Professional experienceRepertoire) – which help to illuminate specific aspects of the CoRe and therefore offer insights intopedagogical content knowledge itself. The results of this study offer new ways of conceptualisingwhat pedagogical content knowledge is and how it might be captured, documented and disseminated.

Key Words: pedagogical content knowledge, science teachers’ professional knowledge, science teach-ing and learning

Purpose

Our research has two main aims:1. to capture pedagogical content knowledge (PCK – the amalgam of content knowl-

edge and teaching knowledge that makes that content better able to be understoodthrough the particular teaching approach adopted); and,

2. to create representations that portray it to others in ways that might be useful inhelping them to recognise and develop their own PCK of particular content.

Therefore, we have been attempting to find ways of portraying good, or well-developed, PCK. Initially cases, as windows into the classroom, seemed a poten-tial vehicle for this. As our understanding developed, we came to define PCK asthe knowledge that a teacher uses to provide teaching situations that help learnersmake sense of particular science content. Through this understanding, it seemedthat classroom windows could potentially catch the complexity of this knowledge inaction. This paper explains how we have developed the link between science content

290 JOHN LOUGHRAN ET AL.

and classroom windows to illuminate the particular approach to teaching particularcontent for particular reasons or science teachers’ pedagogical content knowledge.

Introduction

Shulman’s (1986, 1987) notion of pedagogical content knowledge (PCK) has cre-ated many and varied responses. For some, there is a sense of uncertainty aboutwhat PCK actually is beyond some kind of cognitive functioning of a rather generalnature, whereas for others, PCK has become a way of understanding the complexrelationship between teaching and content through the use of specific teaching ap-proaches for specific reasons. Regardless of these interpretations, PCK has becomean accepted academic construct and, as such, has been closely linked to views asso-ciated with the professional knowledge base of teachers. A common view of PCK isthat it is bound up – and recognisable – in a teacher’s approach to teaching particularcontent; in this case, the teaching of science. The amalgam of a teacher’s pedagogyand understanding of content is thought to be the foundation of one’s PCK suchthat PCK influences a teacher’s teaching in ways that will best engender students’learning science for understanding.

Understanding how science teachers organise and conceptualise their teaching inorder to enhance student understanding of the concepts being taught is a field ofresearch which probes the very essence of teaching itself. “What does a scienceteacher consider when determining how to teach a particular concept?” “Why doesthe science teacher use certain teaching strategies for some concepts and not others?”“What reasoning underpins the science teacher’s practice?” “How does a scienceteacher’s understanding of learning influence their pedagogical reasoning and think-ing?” These questions are at the heart of understanding the specialist knowledge ofscience teaching and are important in determining how knowledge about scienceteaching is developed and refined.

We have been attempting to address many of the questions germane to the codifi-cation of the pedagogical content knowledge of science teachers, and hence to helpdemonstrate the value and importance of such knowledge. Our intention was to cap-ture this knowledge through an adaptation of the use of cases (Mitchell & Mitchell,1997; Shulman, 1992). The initial use of cases led us to develop a construct we calledPaP-eR (Pedagogical and Professional-experience Repertoire) that emerged throughour attempts to better document science teachers’ PCK.

In this article we will not pursue the development of arguments surrounding PCKin detail (see Loughran, Gunstone, Berry, Milroy, & Mulhall (2000) for an exten-sive elaboration). Rather, we will present our working understanding of PCK as ithas been refined through our research, and explain how it has influenced our ap-proach to developing ways of articulating science teachers’ PCK and documentingit for others through the use of PaP-eRs. We provide two examples of PaP-eRs anddemonstrate how their overlapping representations help to portray particular aspectsof pedagogical content knowledge.

DOCUMENTING SCIENCE TEACHERS’ PCK 291

In Search of PCK

Throughout this study we have slowly been developing ways to recognise andrepresent PCK. Initially we conceived science teachers’ PCK to be a recognisableand articulable body of knowledge that experienced science teachers possessed. Weenvisaged finding expert science teachers who more than likely had well developedPCK, but were perhaps unable to personally articulate it. We thought we might beable to see PCK through such things as content specific teaching procedures (roleplays, laboratory work designed and implemented with particular purposes in mind,demonstrations etc.), through discussions with teachers about their teaching, throughclassroom observation, and other traditional approaches to seeing knowledge throughthe practice of experienced science teachers. It is important to state that in our inves-tigations thus far we have confined content to mean science concepts, although werealise that PCK is not limited in this way, and neither we believe are our methods.

It has become increasingly clear to us that although PCK may well exist, it isnot quite so straightforward a process to recognise or articulate as we originallyexpected. There are numerous reasons for this. PCK may not be evident within theconfines of one lesson or teaching experience, and it may well extend over a consid-erable period of time (a unit of work for example). It is clear that PCK is a complexnotion and that science teachers themselves do not use a language that includes (nornecessarily resembles) the construct of PCK, as much of their knowledge of practiceis tacit (see for example, Korthagen and Kessels’ (1999) views of teachers’ Gestaltsas largely unconscious reactions to particular teaching and learning situations). Forscience teachers there is little opportunity, time, expectation or obvious reason toengage in discussions that help them to develop the tacit knowledge of their profes-sional experience into explicit, articulable forms to share across the profession. Wealso now better recognise that the development of PCK is closely tied to the changesin one’s understanding of content, and how teaching that content has influenced thisdevelopment. Yet this is very difficult for teachers to reconstruct since the changesbecome incorporated into existing conceptions without being easily distinguished asnew or necessarily different.

Our first attempt at capturing PCK was through individual interviews with ex-perienced science teachers and attempting to unpack their understanding of theirapproach to teaching a particular content area in science. Although the science teach-ers we interviewed certainly had a very good working knowledge of their teaching,there were noticeable difficulties associated with the articulation of their knowledgeabout their practice. This was in part due to a lack of a common vocabulary aboutteaching and learning, and also because the need to make the tacit nature of theirpractice explicit is not a normal expectation of being a teacher (Bell & Cowie, 1999;Loughran & Northfield, 1996). Teachers commonly share activities, teaching pro-cedures and clever insights into teaching and learning that have implicit purposesin practice, without necessarily articulating the reasons behind them. Attempting totalk about teaching particular content in a particular way often led to descriptionsof practice that were driven by pedagogical reasons other than those most closely

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connected with an understanding of the content (encouraging more active learningfor instance). Interviewees tended to move across a content area without focussing onany particular concepts, thus offering summative views of classroom practice ratherthan rich pictures of content related pedagogy.

We pursued ways of uncovering an individual’s PCK by asking them to considerwhy they taught particular content in a particular way (i.e., what knowledge of teach-ing, learning and specific content influenced their pedagogy). Through this processwe came to see the importance of placing emphasis on the teacher’s understandingof the content: how it had developed and changed; the factors that had influencedthis development; and how teaching the content had altered their understanding ofthe concepts. In pursuing this line of questioning we were hoping to help recreate inthe teacher’s mind the way they had come to know the content and hence make thelink between that knowledge and their teaching approach more explicit.

Throughout this process of individual interviews, there was a notion of PCK as anisolatable item, hence a recognisable data source. We were searching for individualinstances of PCK, or individual lessons where PCK was being used. In one sense, wewere attempting to find identifiable instances where a concrete pedagogic action wasemployed for a particular reason in response to, for example, a learning difficulty, orsituation, or need, or known point of confusion in the content being taught. We weresearching for the triggers (Kadar, 1998) of the practice of expert science teachers.

Although we had insights into teachers’ uses of teaching procedures, we did notfeel as though we were particularly uncovering PCK as it was outlined in the firstsection of this paper: that is, the knowledge influencing their teaching in ways thatwill best engender students’ learning science concepts for understanding. We did,however, see what we considered to be elements of PCK in action: we could see theoverlap of a number of elements influencing in different ways the nature of the ped-agogy of the individuals with whom we were working. PCK was more identifiable,not as an individual item, but as a mixture of items that were not necessarily fixedbut varied with the context of the teaching and learning situation, even if the contentwas the same.

Our research has now led us to contend that to see PCK in the classroom, or ina teacher’s articulation of their practice, is to see a mixture of interacting elementswhich, when combined, help to give insights into the PCK informing the practice.Every single teaching situation is different: it follows that the observable elementsvary, and so the PCK portrayed as informing the practice in any given instance isquite possibly variable itself. Changes in any of the elements observed inevitablyinfluences the nature of the PCK portrayed and it is these observable elements thatare available to us in any portrayal of PCK in action.

As we came to understand what these elements might look like (in some casesby their noticeable absence, as much as by their presence in other situations) wedevised a format to promote discussion of such aspects of teaching amongst groupsof teachers. Through this approach, we hoped that a more comprehensive knowledgebase might therefore be described (presented with greater elaboration later in thispaper, also see Milroy and Mulhall (2000) for a discussion of methodology and theuse of the Content Representation – CoRe).

DOCUMENTING SCIENCE TEACHERS’ PCK 293

We have been able to observe elements that interact with a teacher’s PCK suchas: views of learning; views of teaching; understanding of content – how that un-derstanding has developed and changed; available representations of content; knowl-edge and practice of children’s science/alternative conceptions; means of gaugingstudent understanding of an idea; views of scientific knowledge; pedagogical prac-tice; decision making; reflection; and contextual details (such as time – teachingtime/length of unit/unit of work; and setting – school, classroom, year level, dailydetails, understanding of students).

Attempting to Portray PCK

The early attempts at documenting PCK using a case approach were not as suc-cessful as we had initially envisaged. Our attempts at cases often lacked a dilemma ora hook to bring the reader into the case. In reality, they more resembled a discussionof teaching or an example of a teaching procedure, the sharing of an interesting idea,a lesson plan or an explanation of a unit of work. In hindsight, it is not difficult to seewhy this was the situation. There is a great divergence of elements that we believecan be indicators of PCK. Hence the examples of PCK in action that we encounteredwere not always cases of practice, but rather various insights into particular instances,ideas, and shaping factors of practice. We found that such classroom windows weremore varied in form and were difficult to realistically portray in accord with the intentand purpose of cases. We needed to relax the guidelines to allow for the diversity ofteaching/learning situations that we wanted to portray and so we moved away fromconfining ourselves to a strict case approach.

Through our research, we have come to realise that it is very difficult to offer anexample that is a neat concrete package, able to be analysed and dissected or usedas a blueprint for practice by others. It became obvious to us why there was sucha paucity of concrete examples of PCK in the literature, and our attempts at cases,or classroom windows, seemed only able to capture hints of PCK. These difficultiesin attempting to develop cases of PCK in action are well illustrated in Loughranet al. (2000) whereby the vignette of States of Matter (reconstructed from an earlyinterview with a teacher of Year 9 general science) exemplifies these early attemptsto document PCK and the nature of portraying it to others.

The vignette describes the goings-on in this teacher’s classroom and offers fewhints of the difficulties of either the content or context, and little insight into thedecisions being made. The vignette is the teacher’s response to our attempts to ex-plore the relationship between content and pedagogy but, as it shows, this is notan easy task. It tackles the question: “How do you teach states of matter to year9s?” but does not even start to probe the deeper question of: “What is it that youunderstand about states of matter that is important to take into account when de-ciding how to teach it to this group of students?” It also highlights the difficultiesof trying to apply a case approach to constructing classroom windows when in factthe teaching procedures and ideas are not necessarily viewed as problematic by the

294 JOHN LOUGHRAN ET AL.

teacher, hence diminishing the value of a case approach. Details of our methods ofinquiry have certainly evolved and improved since this interview was conducted, butthis vignette shows that we also needed to develop vehicles of representation thatwere capable of carrying this complexity (in a form accessible and useful to others)as a case approach was not capturing and conveying the situation in the way weinitially anticipated.

Through reflection on what we considered to be lacking in such examples as the vi-gnette States of Matter, we came to better recognise what we believed was needed ina representation of pedagogical content knowledge. Some of these features importantin portraying insights into PCK include:1. classroom reality (the complexity of a real teaching situation including a diversity

of students’ responses);2. teacher’s thinking (about the content and the responses from the students);3. students’ thinking (the links they are/not making and why); and,4. what it is about the content that shapes the teaching and learning and why.

This relationship between portrayal and PCK itself is the complicating factor in thedevelopment of our attempts to both capture and articulate PCK. Science teachers’understanding of the content, their particular views of teaching and learning withina context, and the subtleties of their practice in response to the learning (and other)demands of their students are all insights into their PCK. We would argue that whatis often offered as documentation of PCK lacks the ability to portray the diversityof ways that particular concepts and content are grasped by science teachers andconsequently shape the manner of their teaching. We realised that our portrayals,which we had initially envisaged as cases, could not be full pictures of PCK inaction but rather insights that illustrated the richness of experienced science teachers’pedagogy and professional experience as we came to understand and see this throughtheir repertoires of practice.

Hence, from the classroom window, we have developed the notion of a PaP-eR(Pedagogical and Professional-experience Repertoire) as our way of addressing ourperceived difficulties. A PaP-eR is of a content area because it is the content thatshapes the pedagogy, but it is not necessarily a concrete example of PCK in the waythat a case may be an example of managing a dilemma such as students’ questions(Fox, 1997) or the possibilities for using a new teaching procedure. The notion ofa PaP-eR is not meant to exclude case methodology which itself may also be valu-able in portraying some elements of PCK (see for example, Ingvarson, Livingston,Loughran, & Haslam, 1995; Kleinfeld, 1992).

Constructing PaP-eRs

As outlined above, the variety of insights into classroom practice offered by sci-ence teachers during our interviews, discussions and observations of teaching in-evitably meant that instances of particular aspects of PCK were ever present. Gener-ally, PaP-eRs therefore developed from the detailed descriptions offered by individ-

DOCUMENTING SCIENCE TEACHERS’ PCK 295

ual teachers from our interview groups or as a result of discussions about situationswe had observed or were told about by participants.

A PaP-eR therefore develops through the interaction of the questions, issues anddifficulties that are noted by the other teachers and ourselves during interviews fol-lowing the initial input of an episode by a member of the group. Through the draftingof the PaP-eR that follows, the episode is reconstructed in a communicable form thatis intended to carry the meaning that is not always explicitly embedded in typicaldescriptions of teaching practice. Hence, although a PaP-eR is generally drawn fromone teacher’s practice, the development of the final PaP-eR is as a result of theinteraction of all involved in an interview group. This is not meant to imply thoughthat all PaP-eRs are developed in this way. For example, one interesting aspect of thePaP-eRs below is that they were constructed by two teachers as they reflected on theirteaching of that particular content. In their case, they were teaching the same scienceclasses together (team-teaching) and were constantly sharing their teaching ideas andthe purposes of their pedagogy with one another as they organised and taught theirlessons. Their need to know the thinking that underpinned one another’s pedagogycreated an opportunity for documentation that is uncommon in most science teachingsituations, but in this case, created PaP-eR possibilities as a consequence of theirnormal practice.

PaP-eRs therefore are a development that emerge from teachers’ actual practice(some initiated by us as a result of classroom observation) and reflect the input ofthe originator of the teaching episode, the research team and other involved scienceteachers. The final PaP-eR is validated by the original teacher to be sure that detailsare correct and that the thinking, actions and observations in the PaP-eR genuinelyreflect that which was originally intended.

Our conception and development of PaP-eRs as a form for portraying PCK hingeson two important issues.1. PaP-eRs are of a particular content area – and are therefore attached to that

content.2. One PaP-eR cannot alone carry PCK – a diversity of PaP-eRs helps to shed light

on the different aspects of PCK.If a representation of PCK is to help teachers to recognise, articulate and develop

their understanding of that content, then clearly it must be based on an understandingof what it is about the content that the teacher knows (and has come to understand)in order to purposefully shape the pedagogy and the associated approach to studentlearning. As a classroom window, a PaP-eR has the advantage of being set in a con-text where the learners are interacting with the subject matter. At the same time thiscarries the danger of being merely an idiosyncratic account (van Driel, Verloop, &de Vos, 1998). However, to carry the weight of the more comprehensive knowledgeinforming the practice shown, would make such an account too cumbersome to beengaging or useful.

We therefore propose a central content representation (CoRe) that sets out anddiscusses the aspects of PCK most attached to that content, and most likely to extend

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Important science ideas/concepts (Content Core)

Big idea 1 Big idea 2 Etc.

Why it is important?

What you intend the stu-dents to learn about thisidea?

Difficulties/limitations con-nected with teaching thisidea.

Knowledge about studentswhich influences your teach-ing of this idea.

Other factors that influenceyour teaching of this idea.

Teaching strategies (and par-ticular reasons for usingthese to engage with thisidea).

Specific ways of ascertain-ing students’ understandingor confusion around thisidea (include likely range ofresponses).

Figure 1: CoRe (Content Representation) linked to PaP-eRs.

across various contexts (such as, for example, an overview of the main ideas; knowl-edge of alternative conceptions; insightful ways of testing for understanding; knownpoints of confusion; effective sequencing; and, important approaches to the framingof ideas). This CoRe is illustrated in Figure 1.

It is crucial that we emphasise that the current form of this CoRe is in fact a versionof what we have been using as a methodology for accessing science teachers’ under-standing of the content. It should not be viewed as static or as the only/best/correctrepresentation. It is a necessary but incomplete generalisation resulting from workwith teachers. It is being used to help codify teachers’ knowledge so that the linksbetween the CoRe and the PaP-eRs attached to it are meaningful, and demonstratewhich aspects of PCK are informing the classroom practice portrayed in the PaP-eRs. It helps to make the complexity accessible and manageable, and hence po-tentially better able to be shared. Through our research we have come to see thevalue in putting this CoRe together through the interaction of groups of teachers andresearchers (see Mulhall et al., 2000).

Attached to this CoRe are the PaP-eRs, with links to the aspects of this field thatthey bring to life through windows on how such knowledge might inform effectiveclassroom practice (see Figure 1 for an overview of this linkage between CoRe andPaP-eRs).

DOCUMENTING SCIENCE TEACHERS’ PCK 297

A PaP-eR must allow us to look inside a teaching/learning situation where it is thecontent that shapes the pedagogy. The PaP-eR should have explicit links that help toconnect the practice seen, with the explicit body of knowledge about the CoRe. Thoselinks should illuminate the decisions underpinning the teacher’s actions intended tohelp the learners make sense of the content.

The PaP-eRs are about teaching that content in that context and help to illustrateaspects of PCK in action. One PaP-eR alone is not enough to illustrate the complexityof the knowledge around the content. Including a collection of PaP-eRs attached todifferent (but probably overlapping) areas of the CoRe also helps to highlight someof the different blends of elements that jointly indicate an individual’s (or group ofscience teachers’) PCK. The overlap, the interplay, and the relationship between PaP-eRs in a content area are important in viewing the complex nature of PCK withoutany one PaP-eR being regarded as the nature of PCK itself.1 To illustrate this weoffer the following two PaP-eRs on the Circulatory System, and indicate some of thefields they might illuminate in relation to the CoRe (Table 1).

PaP-eR 1

A PaP-eR of the circulatory system: Not just a thing, but a need for a function

Our thinking Commonly, children associate blood almost exclusively with the heart,with cuts and injuries, and perhaps with a pulse rate, without ever wondering whyit is that we have blood circulating in our bodies. If they do consider the idea of theblood carrying food and oxygen for our bodies to use, they tend to think that the heartis the source of these nutritional needs, or that they are just in the blood itself. Thereis little awareness of the interdependence between body systems (this is aggravatedby the body systems commonly being treated discretely and separately).

The notion of disposal of cellular waste is rarely even considered – the prevalent,naive view is that waste is disposed of as faeces and urine, but that both of these areproducts of the digestive system. Often faeces are seen as waste food and urine aswaste drink.

A colleague and I decided that it was important to begin a year 9 unit about thecirculatory system with students finding a need for it to exist. We felt that introducingthe various components and then putting them together (a common approach) wasunlikely to lead to students developing a picture of the circulatory system as a func-tioning whole. They had to have an understanding of what the circulatory systemdid, and this in turn would create further needs for the components of the system,and also for the interconnections with other body systems.

We adapted the Body Systems approach (Loughran & Corrigan, 1991) with afundamental change. Rather than asking students to generate a picture of a bodysystem first and then tracking progress of molecules through the body (this is usefulfor review and consolidation), we asked them to consider molecules entering thebody with the intent of this leading to a need for the body systems.

In the classroom Following is an extract taken from a teaching journal.

298 JOHN LOUGHRAN ET AL.

Tabl

e1

Con

tent

Cor

eof

Hum

anC

ircu

lati

onSy

stem

toA

ccom

pany

the

Two

Pape

rs“

Not

just

aT

hing

,but

aN

eed

for

aF

unct

ion”

and

“R

oadw

orks

”.

DOCUMENTING SCIENCE TEACHERS’ PCK 299

Tabl

e1

(Con

tinu

ed.)

300 JOHN LOUGHRAN ET AL.

Quiet music playing as the girls came in dribs and drabs and moved to their seats. Each place had amarshmallow sitting there on a serviette. It wasn’t necessary to tell them not to eat it – they seemed quitereverent about it! It was quite good letting them wonder about the marshmallows as everyone arrived. Iasked them to have their books open to a ‘thinking page’ and to have a pen ready.

Me: Look at your marshmallow. Now chew it slowly with your eyes shut. Think aboutwhat is happening to it as you swallow it. This is a silent activity. Where is themarshmallow going? What is happening to it? Write your ideas on your thinkingpage – and please don’t talk yet. Where will the marshmallow be in 1 hour? . . . in 2hours? What will have happened to it? Where will it have gone? How about after 6hours? . . . 12 hours? . . . in 24 hours time?

They formed their own groups as I gave out huge sheets of butcher’s paper and textas. They had to drawa body outline (around a volunteer) and then show the marshmallow’s progress over 24 hours.

After about 15 minutes I got everyone to move around the lab looking for similarities and differences.There was a fair variety in the amount of detail shown about the digestive system (“but we did this lastyear Miss”), but only one group indicated that some ‘nutrition’ would go from the stomach ‘into the body.’Back at their own ‘bodies’ most changes involved improving the details of the digestive system. Now Istarted to ask the million dollar question. . .

Me: Why do we eat food? Why do we bother?

Students: We need the food for our bodies to work. It gives us energy. We need energy tomove. We need vitamins and minerals and things like that.

We get the stuff for our bones and everything from our food.

Me: But if the marshmallow goes in here and 24 hours later it comes out here, then whywould we bother eating it? (OK – besides the taste).

Some people objected to a marshmallow being food, as opposed to junk food, which caused lively discus-sion. “It’s got lots of sugar and the sugar gives us energy.” With some groups I told them to think about apizza then.

Every group started talking about ‘using’ some of the marshmallow. Arrows started to appear – mostlyradiating from the ‘stomach.’ A couple of groups had them coming from the small intestine too. Thearrows radiated out into ‘the body.’ Louisa even said that, “vitamins and minerals go through the villi ofthe small intestine”, and Genwa suggested that protein came out, “because we need protein.” For a handfulof students the details of last year started coming back.

As a class we talked about the marshmallow. Yes, some of it “went right through” and came out as waste.But what happened to the rest? The consensus was definitely that the “good bits” of the marshmallowwent through the walls of the digestive system into the body to be “used in the cells.”

Me: So how do they get to the cells? How does a cell in your middle toe[brain/elbow/ovary] get all the energy and nutrients that it needs to keep functioningif it is such a long way from your intestine?

Students: It gets there in the blood. It gets into your blood and then travels in the blood ‘towhere it is needed.

The blood takes it to all of the cells.

Homework: to write 8–10 questions about ideas arising from today’s lesson.

Next lesson: Drama room is booked. Get them to lie on the floor with eyes closed. Breathe slowly anddeeply. Get them to think about the breath of air – what happens to it? Why do we breathe? What do weneed oxygen for? Where does the oxygen go? etc.

Then get them to add their thoughts to their bodies (similar process to today). It should be quicker becauseof today’s lesson, although they are less familiar with the respiratory system than the digestive system.

DOCUMENTING SCIENCE TEACHERS’ PCK 301

Throughout the unit we return to these body pictures to modify them as we buildup a picture of the circulatory system; to think about interfaces and transfer betweensystems; to think about waste transport; and to revise ideas later in the unit. Theyare fabulous for probing ideas, assessing understanding, promoting curiosity, andteaching, all at once, in a small group setting. Vitally however, we find that startingthe unit with these visualisation activities helps to get prior (working) knowledgeout, and sets the class off with a need to set the functioning circulatory system in.

PaP-eR 2

A PaP-eR of the circulatory system: Roadworks

Our thinking The thinking behind the analogy task: Many teaching resources aboutthe human circulatory system draw upon a “transport” analogy where blood vesselsare compared with roadways leading to a central location; the heart. I often wonderwhat sense my students make of such a representation.

In order to explore their thinking about a transport system analogy, I ask my stu-dents, in pairs, to select and describe appropriate symbols for the various componentsand related organs of the circulatory system as a transport system. Student pairs mustdecide, for example, how they will represent red and white blood cells as elements ofa road transport system. Their choice must be consistent with function and togetherthe symbols must be ‘sensibly’ connected. I find that this task assists students toconsider the adequacy of their own understanding of the various components asthey attempt to create a series of workable symbols. Through manipulating theirknowledge in a new way, I anticipate that their understanding of this system, and itslinks with other body systems, will be enhanced.

I have found that it is important that this task is not presented too early in thelearning sequence. In order for the analogy task to be meaningful – a genuine explo-ration and extension of students’ knowledge – students must have sufficient contentknowledge of the human circulatory system to draw upon in selecting and describingtheir symbols. The scene must be set carefully so that students are able to recogniseand draw upon what they have learnt. This involves me helping them to feel confidentabout what they already know.

Two other aspects of this analogy task are also important in its teaching. First, thecontext of the analogy must be familiar to the students. In this case, students need toknow about road transport systems. We spend time together as a class brainstormingthe different kinds of vehicles, types of roads, etc. that comprise a road transportsystem. Secondly, students need to realise that as well as being helpful comparisons,analogies have limitations. The most exciting moments (for me) in helping studentsto develop their symbols is when they come to see that no one symbol can completelyrepresent all the functions of one particular component of the circulatory system.

The task in action My approach to the lesson was based on the idea that studentscould create an analogy for the human blood circulatory system by representing itas a road system. I asked them to work in pairs and to choose appropriate transport

302 JOHN LOUGHRAN ET AL.

related symbols to represent various components and related organs of the bloodsystem. Each pair of students had fifteen items that they were asked to convert intosymbols consistent with the analogy of a road transport system then present thesesymbols on a poster sized map. They were also required to provide a short writtenjustification for each of the symbols that they chose.

If we were to look in on a class we’d see frequent calls to me for help, for example,“Miss, we can’t think of a symbol for the small intestine.” This would lead me tothe question, “What does the small intestine have to do with the blood circulatorysystem?” In anticipation of developing acceptable responses like, “Bits of food gointo the blood from the small intestine,” or better still:

. . . the products of digestion small enough to be absorbed through the walls of the villi of the smallintestine move into the blood stream and from there are carried around the body to supply the energyrequirements of cells.

But those responses only happen if the students have really thought through thecomparison they are trying to make, therefore their understanding of the componentsreally matters (e.g., the link between the small intestine and the blood circulatorysystem) because the analogy task relies on students being able to synthesise andmentally manipulate their understanding of the blood system.

To encourage the students to be self-reliant and to do this synthesis themselves, theonly assistance you would see me offer would be to give them a set of photocopiedquestions designed to encourage them to ensure that certain groups of symbols madesense together. For example, “What is the job that red blood cells do? Look at thesymbol you have chosen for the red blood cells. Does the symbol you have chosenshow the red blood cells doing this kind of job? What links have you made betweenred blood cells, oxygen and the lungs? Do the symbols make sense together?” andso on.

Although it is hard to leave the students to explore their understanding withoutundue teacher interference (or direction), it does make a difference because theybegin to question themselves, therefore, I’d be wandering around listening to themsay things like: “But how could the intestines be like a supermarket?” “What do thekidneys actually do?” “If sugars are used up and turned into energy inside a cell, thenpeople can’t be the symbol for sugars because people don’t get used up!”

Through their discussion, I’d be hearing students discuss how unlikely it wasthat symbols could be found to adequately represent the raw materials for energyproduction in a cell – because there were limitations with whatever symbols theychose.

By encouraging the students to use their knowledge and by not giving them myanswers, they’d be beginning to understand the content and you’d even see somerecognise the limitations of analogy. You’d see this happening because (as long asthe task was introduced at the right time) they’d have built up enough knowledgeabout the circulatory system before they started to create symbols for its variouscomponents thus purposefully bringing their knowledge of the circulatory system tobear on the task as they grappled with synthesising and reworking their knowledge.

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Looking into this class would show the students building their understandingthrough the task in ways that I have come to know does not happen easily if theteacher does not carefully monitor the students’ content needs in advance of attempt-ing to use the knowledge to develop understanding.

Links to a CoRe

As part of a collection, these two PaP-eRs would map onto the areas that theyilluminate of a CoRe of teacher knowledge of the circulatory system. If we visualisethis in terms of Figure 1, then the links could connect these PaP-eRs in the followingways. Not Just a Thing, but a Need for a Function brings to life the following mainscience ideas or concepts: circulatory system as a functioning whole; interconnec-tions between body systems (in this case digestive and respiratory); and disposal ofcell waste.

We would see connections to various points in the columns below these big ideas,for instance to teaching procedures and to knowledge of students such as the preva-lence of the misconception about the heart as the source of nutritional needs. Road-works brings to life the main ideas: circulatory system as a functioning whole; inter-connections between body systems; and, understanding the functions of the variouscomponents of the circulatory system. The connections to the aspects of teachingthese big ideas would link into areas such as difficulties/limitations in teaching aboutthis idea and teaching procedures (and reasons. . .) (Figure 1).

These two PaP-eRs overlap in the elements of PCK of the circulatory system thatthey portray. One describes a teaching procedure that the teacher uses as the topic isintroduced, while the other is employed to help students synthesise their knowledgeof the circulatory system towards the end of the unit. This highlights one of thedifficulties in capturing PCK of particular science concepts – the ideas themselvesare not dealt with neatly in isolation. Such an unrealistic ordering would lead to littleuseful understanding, and hence is not a feature of the reality of helping learnersto understand difficult science content. Our intention is that the overlap of PaP-eRs,linked by an articulated representation of knowledge about teaching that content, isa way of making sense of this complexity (Figure 1).

It can be seen that a more comprehensive working of the CoRe combined with adiverse collection of PaP-eRs about teaching about the circulatory system could bea way to portray the reality of, and the knowledge underlying, teaching this contenteffectively in the classroom.

Overview

We do not envisage that PaP-eRs should have a particular format or style. APaP-eR should be an engaging portrayal of the elements of PCK that are beingillustrated for the reader. PaP-eRs should have a variety of formats (e.g., interview,

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observer’s voice, journals, window into a lesson, students’ voice and actions, anno-tated resources and so on) so that their portrayal allows the reader to identify withthe situation and, as a result of the particular framing of the pedagogy, content andcontext, to draw meaning from it.

In concert with the PaP-eRs, the CoRe (Figure 1) must be conceptualised as anecessary construction to codify and categorise the knowledge and content underconsideration so that it might be manageable and useful for others. Well-constructedPaP-eRs should then bring this CoRe to life and shed new light on the complexnature of PCK both for teachers and educational researchers. This we see as one wayof helping to create opportunities to better understand, and hence value, the specialistknowledge and skills of teachers and to make the tacit explicit for all audiences.

We realise that the use of PaP-eRs as insights into elements of PCK has moved aconsiderable distance from case methodology as it is generally used. However, ourproposed approach through the use of PaP-eRs still contains many of the qualitiesthat first inspired this investigation so that portrayal of PCK might be possible. Wecontend that PaP-eRs then need to:1. capture the rich detail of classrooms so that they ring true with teachers and

engage them in thinking through a real situation;2. act as stimuli for reader thought and discussion and explicitly link to the CoRe;3. illustrate some of the CoRe, and/or be the way in to reading a PaP-eR – grappling

with the questions it raises may be the way a reader comes to consider certainaspects of the content in the first place, or comes to reconceptualise and extendtheir understanding of the content;

4. illuminate dimensions of teacher thought in concert with classroom action, par-ticularly so in relation to the thoughts and actions that combine in teaching par-ticular content to particular students so that students’ learning is enhanced.

Professional Development Using CoRe and PaP-eRs

Roth (1998) argues that the subtleties of quality teaching may defy analysis, yetthrough our research we have come to see the need to work to illuminate practice sothat it can be viewed, analysed and understood by others.

In working with experienced science teachers, our methodology for capturingand portraying PCK has developed through constant feedback and experimentation.Teachers have been involved so far both individually, and as groups helping to de-velop the CoRe. In both forums the benefits of such discussions have been alluded toby participants. As we have pursued our research agenda we have come to understandthat the science teachers we have worked with have in fact recognised importantinsights into their own practice and experienced a genuine sense of professional de-velopment. This professional development has been evident in the manner in whichthey have negotiated a language of practice through which to share their knowledgeof teaching as well as the subtleties of their constructions and understandings of par-ticular science content knowledge (see Mulhall et al. (2000), for further discussionof these methods).

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We see a collection of PaP-eRs attached to a CoRe as having two main purposes:1. to demonstrate the complexity and value of such developed teacher knowledge;

and,2. to be useful to the profession as a tool to help both practising and beginning

teachers develop their PCK of particular content.As a professional development tool PaP-eRs might be helpful if used in ways

similar to cases. These accounts should help promote discussion amongst groups ofteachers, or could be used as illustrations in a resource for individual teachers, whilethe CoRe provides a linked framework for exploring the knowledge base that thePaP-eRs bring to life. It is envisaged that this framework should help teachers toarticulate, analyse and explore their own PCK of particular content, identifying ordeveloping aspects of that knowledge that could help them overcome obstacles inhelping students to understand particular concepts embedded in the science content.

For example, a teacher approaching a unit of work that they will be teaching forthe first time might find such a representation helpful in developing and refining theircontent knowledge of that specific topic so that their PCK is similarly enhanced. Ora science faculty within a school might use this resource when reviewing the units intheir year 8 curriculum. The PaP-eRs could provide a stimulus for discussion, whilethe central framework might be used to structure their review.

We intend that PaP-eR collections should provide a resource for the profession,both as representations of PCK of particular content, and as a way for others toexplore, develop and document areas of PCK themselves.

Conclusion

Through our research into PCK we have been confronted by many difficulties as-sociated with attempting to make the tacit knowledge of experienced science teachersexplicit for ourselves and others. One such important issue that has emerged is clearlyrelated to cases as a construct and a method for capturing and portraying teachers’knowledge.

As teachers and researchers experienced in writing and using cases in professionaldevelopment activities, we are conscious of the value of cases. Our understanding oftheir structure and use, and the importance of the particular meaning and understand-ing that accompanies the use of the term cases, inevitably meant that we did not wantto contribute to cases becoming another term that meant different things to differentpeople (as has happened with so many other important educational ideas).

We came to believe that cases were unable to carry the weight of all that is neededin a portrayal of PCK because of the reasons outlined in this paper. Recognisingthe complexity of the relationship between the PCK and the portrayal(s) that wewere attempting to construct, meant that cases simply could not carry all that wasnecessary and still be cases. Hence our differentiation between the use of a CoReand the development of PaP-eRs – for us, this was a breakthrough in being ableto better illustrate the inherent difficulties in defining and capturing PCK, without

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reducing it to a mechanistic, technical rational documentation of teaching, learningand content. We trust that the explication of our argument illustrates that using acollection of PaP-eRs connected to a codification of the knowledge surrounding theteaching of particular content can overcome this problem. Shifting the weight of thisknowledge away from the individual classroom windows at the same time allows usto make it explicit in a more manageable, and hence more useful, form.

Finally, the value of this approach is perhaps also enmeshed in an understandingof validity. As Guba (1981) highlights, allowing the reader to decide the extent towhich what is read is relevant to their particular contexts is an important featureof naturalistic inquiry. We trust that our forms of representation (portrayed throughthe use of a CoRe and PaP-eRs) offers sufficient context for the reader to developan understanding of the complex nature of the teaching and learning tied to thatparticular content. If so, then the notion that one standard exemplar of PCK can beused as a yardstick of PCK in action clearly becomes untenable and illustrates whyso much of the literature talks about PCK but does not illustrate concrete examplesof PCK. It is also why we believe that a case approach has not worked as suchcomplexity can not be carried through a single all encompassing case.

Note

1. This also illustrates why one can not pin-point particular PCK items in waysthat teacher-testers might like, for the interplay and relationships are too complex tobe held still to individually capture and measure.

Correspondence: John Loughran, Faculty of Education, Monash University,Wellington Rd, Clayton, 3168, AustraliaE-mail: John.Loughran@Education.monash.edu.au

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