Teachers’ and pupils’ scientific dialogue in learning about invisible thermal phenomena

ABSTRACT

In science education research, there is a growing body of studies focusing on the role of multiple representations in pupils’ learning. This study is based on a social semiotic perspective and in the analysis, there is a special focus on how the content is conveyed and how relations are created through interaction between teachers/pupils and the infrared camera and between teachers and pupils. We report the results from a pilot study involving one teacher’s work with thermal phenomena in grade 6. A class of 45 primary pupils, divided in 4 groups. Overall, we describe findings from three lessons involving experiments situated in pupils’ everyday experiences of thermal phenomena. In the analysis, we focus on two groups of pupils (N = 25) and data are generated from three lessons by video and audio recordings. With the help of the infrared camera, the pupils manage to represent heat as a process. The infrared camera provides a visual interface for a shared point of reference and is an important semiotic resource for stimulating verbal communication between pupils and between pupils and teachers.

KEYWORDS:

• Language in classroom
• physics education
• elementary/primary school

Introduction

In science education research, there is a growing body of studies focusing on the role of multiple representations in pupils’ learning (Tang et al., 2014) and increasingly affordable visualisation technology presents opportunities for pupils to learn science concepts by making the invisible visible.

There have been an extensive number of studies about pupils’ and teachers’ conceptions of the physical concept of temperature and where the focus should be, when it comes to teaching and learning this concept, during the last three decades (e.g. de Berg, 2008). For instance, it has been reported that pupils tend to have an everyday conceptualisation in which heat and temperature are different names for the same phenomenon (Almahdi, 2011; Wiser & Amin, 2001). In their study of heat, Wiser and Amin (2001) look at language integration between everyday language and formal scientific language to gain a higher level of understanding. They stress the fact that a word like ‘heat' appearing in both languages results in the need for an explicit awareness in science education and practice, by discussing the differences between the two languages. In addition, it has also been recognised that pupils have difficulties adopting and understanding the fundamental idea of heat transfer by conduction (Haglund, Jeppsson, & Schönborn, 2016). Erickson (Erickson & Tiberghien, 1985) studied children’s (4–13 years) understanding of heat and temperature, and found that children are aware of heat transfer from a hot object to a cold object. Pupils do have difficulties understanding that objects in a room have the same temperature, because they do not take into consideration that the objects interact with the environment, for example, the air in the system. Erickson also emphasizes that, if pupils were able to see the transfer of energy, this problem would be more uncommon. Furthermore, the children have difficulties distinguishing between the concepts of heat and temperature. Tiberghien (Erickson & Tiberghien, 1985) emphasises that not all pupils (10–14 years) are aware that the temperature rises for all substances when heated – instead, pupils think it depends on the matter.

By the use of infrared cameras (IR cameras), it is now possible to visualise physical phenomena such as friction, electricity and thermal physics. IR cameras help pupils to discover physical phenomena that they otherwise have to accept as true (Vollmer et al., 2001). Visualising heat and thermal conductivity by the use of IR camera has been shown to have a positive impact on pupils’ understanding of these concepts (Haglund et al., 2014, 2015; Xie & Hazzard, 2011). Xie and Hazzard (2011) emphasise that the IR camera demystifies heat transport and makes the concepts ‘speak for themselves'. Cabello et al. (2006) have shown that the use of IR cameras facilitates pupils’ understanding, and tends to make them become more motivated in the subject. Haglund et al. (2014) have developed and implemented laboratory work in physics for primary and secondary schools, and their findings indicate that the IR camera has a positive effect by guiding the focus of pupils’ attention to the intended studied object. In their case, they have focused on heat conductivity and heat transfer at primary and secondary school levels. In addition, Haglund et al. (2015) have also shown that the IR camera also serves as a pedagogical instrument in subjects like biology and chemistry. As argued by Jeppsson et al. (2017), the IR camera may serve as a shared point of attention (Schoultz et al., 2001) in pupils’ dialogue when talking about invisible phenomena such as heat conduction and heat transfer. Even if the IR camera has been shown to have many advantages in relation to stimulating pupils’ dialogue when learning about central ideas of thermal concepts, research has also shown that pupils sometimes may misinterpret the visualisation image and may be confused when the IR camera calibrates towards the surroundings. According to Schönborn et al. (2014), pupils need to have some prior understanding of the concepts of heat and temperature so they can interpret the visualisation of the IR camera. Along the lines of Jeppsson et al. (2017) reasoning about seeing the IR camera as a shared point of attention, Samuelsson et al. (2017) have shown that students’ work with IR cameras may stimulate a playful approach for students to learn about thermal concepts such as visualising the chemical reaction when table salt is sprinkled over ice. Samuelsson et al. (2017) also point to the fact that the IR camera itself invites students to extend the experiment and start to pose their own questions, such as ‘What would happen if we did this in a different way?'. As we see, prior research has shown that the IR camera invites students to start talking science. However, in our study, we are interested in the dialogue per se and not so much on the affordance of the IR camera itself.

Many scholars have highlighted the importance of meta-discussion in relation to pupils’ meaning-making in science (Lemke, 1998; Tang et al., 2011). Tang et al. (2011) highlight that verbal spoken language between pupils, and between pupils and teachers, play an important role for meaning-making of abstract symbols and scientific concepts. How teachers use verbal language in their conversations with pupils, and how open questions are used by teachers, are important aspects regarding pupils’ learning trajectories from everyday language use towards disciplinary knowledge within a subject (Nygård Larsson, 2018). Nygård Larsson (2018) found that teachers build their lessons on pupils’ context-based expression, and then guide the pupils’ ideas and experiences toward a more disciplinary scientific language. The pupils’ context-based expression usually consisted of verbs, while the teacher’s scientific expression was a nominalisation of these verbs. Bergh Nestlog (2012, 2019) emphasises teaching and the link between the content that is conveyed, how the content is conveyed and how relationships to the content are created between artefacts, teachers and pupils, and between pupils and pupils, in order to facilitate a meaning-making process for pupils. In her analysis, she developed the model of variables of practice discourse (Figure 1), which focuses on how and why meaning making may occur during teaching, based on the discourse.

Figure 1. Variables of practice discourse (cf. Bergh Nestlog, 2012).

The model is based on the three practice variables, practice voices, practice form and practice field, and by using systemic functional linguistics (SFL) in the analysis, she focuses on the mobility of pupils’ and teachers’ orientation among and between the three above-mentioned functions. By studying the practice field, you focus on the content of the teaching. Within the variable practice voices, the participants and the interactions between them are in focus. The last variable, practice form, highlights how the subject (practice field) is communicated by the practice voices.

Theoretical background

The theoretical perspective in this paper stems from social semiotics (Jewitt, 2009; Kress, 2010) and the framework of systemic functional linguistics, SFL (Halliday & Matthiessen, 2004). Every time we express ourselves, we say something about the world, or rather our experience of the world. At the same time, we use language to participate in various types of social activities, which means that with the help of language we control our relationships with the person or people we communicate with. In addition, we organise the information we provide. Our expression about the world says something about how we interpret and understand the world around us. This leads to the conclusion that our meaning-making is based on the social actions we take part in. Social semiotics focus on communications in social groups where different semiotic resources are used. Studies adopting a social semiotic perspective have a strong emphasis on the context in the analysis (Danielsson & Selander, 2014; Jewitt, 2009). The focus in social semiotic analysis is on how people use the involved semiotic resources in a situated social context. Semiotic resources are the actions, materials and artefacts we use in our communications, which are used to communicate a particular purpose. In relation to our study, we regard the IR camera as a semiotic resource.

One of the main areas in SFL is to focus on meaning-making, and the central ideas in SFL seek to understand how people communicate by a variety of means in particular social settings with a range of semiotic resources. In the current study, the interaction between the pupils, the teacher and the IR camera, is described from this perspective, through which representations are considered in terms of the interpersonal, ideational and textual metafunction (Halliday, 1978; Halliday & Matthiessen, 2004). The interpersonal metafunction answers questions such as who is taking part in the situation, and focuses on the relationships between the people and what kind of exchanges happen in the conversations (Knain, 2015). In this study, the interpersonal metafunction is extended to include the relationship between pupils and the IR camera image. In the analysis, we describe the role of the teacher in relation to conversation in terms of primary speech function (Knain, 2015). This type of speech function includes the following types of functions: a claim, a question, an offer or an exhortation by the teacher in the conversations (Holmberg, 2006; Knain, 2015). Depending on the outcome of the conversations, the teacher either affirms or rejects pupils’ responses. The pupils’ ideas of what is going on in the experiment constitute the pupils’ meaning-making in relation to ideational metafunction. This metafunction corresponds to the question of what content is conveyed (Jewitt et al., 2016; Knain, 2015). Through the ideational metafunction we describe the teacher’s and pupils’ meaning of heat conduction and insulation, in relation to science teaching practice at the primary level. The textual metafunction is related to how meaning is organised within a particular context (Jewitt et al., 2016; Knain, 2015). Within our study we analyse how pupils’ focus shifts during their overarching theme work with heat conduction and insulation, and we are particularly interested in the link between the ideational and interpersonal metafunction in relation to the pupils’ meaning-making of the involved thermal concepts.

Grounded on the three metafunctions, we focus on six variables of practice discourse (Bergh Nestlog, 2012, 2019) in our analysis as a way to explain the relationships between artefact (IR camera), teacher and pupils in their meaning-making process. The model is an adaptation of SFL in order to describe classroom discourse. By using the six variables of the school discourse in the analysis, we want to illuminate how and why the subject becomes part of the pupils' understanding in the practical implementation in the context. Related to the three metafunctions, described above, interpersonal metafunction is associated with practice voices, ideational metafunction refers to practice field, and the three sub-categories (subject voices, subject content and subject textuality) and textual metafunction relate to practice form. Focusing on the six variables gives a broader picture of the teaching based on the content and the interaction with the participants and Bergh Nestlog’s (2012) model within the SFL framework provides opportunities and tools for analysing the variables within a classroom discourse.

Aim and research questions

The aim of this study is to investigate how the IR camera supports teachers’ and pupils’ scientific communication in learning about heat conduction and insulation. Hence, this study is guided by the following research questions:

• What characterises communication in science teaching targeting the concepts of heat conduction and insulation?

• In what way is meaning-making offered by the teacher to the pupils in their work with heat conduction and insulation?

Method

This study is part of a larger project, and this particular data set involves one teacher’s work with thermal phenomena in Grade 6 (12-13 years) with 45 pupils, divided into two classes or four groups. During teaching-led lessons the pupils were divided into two classes (A and B), and in laboratory work the pupils were divided into four groups (A1, A2, B1 and B2). Class A includes groups A1 and A2, and class B includes groups B1 and B2 In the results section we have given pupils and the teacher fictive names.

Before the teacher introduced the pupils to the topic of heat conduction and insulation, the teacher participated in a workshop together with the first author of this paper. The purpose of the workshop was to let the teacher get acquainted with the IR camera and its functions. In addition, based on previous research involving IR cameras, thermal phenomena and school science practice (e.g. Haglund et al., 2014; Haglund, Jeppsson, Melander, et al., 2016), this workshop also gave the opportunity for the teacher and the researcher to discuss educational challenges and implications. However, based on this workshop, the teacher chose to use the following six experiments: how ice melts while in contact with various materials such as paper and a china plate; conductivity through paper and copper strips; heat radiation on black and white paper; frictions of an eraser on a table and dropping a ball on a floor; how to conserve heat in a thermos; and the insulating properties of a quilted jacket.

Based on the workshop, the teacher made a plan for three separate lessons for the pupils (see Table 1).

Table 1. Overview for lessons, participating pupils and method of data collection.

Activity	Group	Data collection
Workshop	Researcher and teacher	Audio recording
Lesson 1	45 pupils in four groups	Video and audio recording (four groups)
Lesson 2	45 pupils in four groups	Video and audio recording (four groups)
Lesson 3	45 pupils in two classes	Video and audio recording (one class)

During the first lesson, the pupils constructed a thermos. For the thermos construction experiment, the pupils used a 0.5 L PET bottle, and based on their ideas they could use materials such as styrofoam, textiles, tape, cotton wool and tinfoil in order to insulate the thermos. During Lesson 2 (laboratory work), the pupils worked with the six selected experiments, using the IR camera. All the experiments involved a predict, observe and explain (POE) approach as a method (White, 1992). The third lesson was a teacher-led lesson with a summary discussion and conclusions of the experiments. From Lesson 3, there was only a recording from one class, which affected which data were used from Lesson 2. Overall, in this study, we describe findings from A1 and A2 (25 pupils). We have collected our data by use of video and audio recordings from Lesson 2 and Lesson 3. During these lessons the teacher and pupils used and/or discussed their results based on the IR camera.

Between Lesson 1 and Lesson 2 the teacher handed out laboratory guides to the pupils, and the pupils wrote down their own predictions in relation to the experiments. This particular occasion was not video-recorded.

In all the involved experiments the pupil used a FlirOne IR camera. This particular IR camera is attached to an iPad and is cheaper than other IR cameras.

Data collection and analysis

The empirical data that served as the basis for the analysis reported in this paper was collected as part of a larger project with a focus on teachers’ professional development. The data in focus for this study consists of field notes and video and audio recordings from Lesson 2 and Lesson 3. A verbatim transcript of the video and audio recordings from Lesson 2 and Lesson 3 was written in MAXQDA software to support the subsequent SFL qualitative data analysis (see below). The analysis was performed based on the Swedish transcript by the first author. Examples provided to illustrate the results have been translated into English.

Chi’s (1997) procedure for analysing qualitative data served as a guide in our analysis. Both lessons were analysed as a whole. First, the transcript for each lesson was divided up into episodes that reflected the interpersonal, ideational and textual metafunction. This allowed for coherent stretches of reasoning to serve as the basis for analysis of the particular role played by different metafunctions. Thereafter, the first round of the analysis was discussed with other researchers with a special research interest in social semiotics. Finally, the method and analysis were presented and discussed at different seminars at our department and at different national science education conferences. In the subsequent paragraph, we elaborate on the different metafunctions in relation to variables of practice discourse in order to carry out an in-depth analysis.

In this second phase of the analysis we focused on practice voices, practice field and practice form, which all correspond to the different metafunctions (Figure 1 and Table 2). In the dialogue between the teacher, pupils, texts and IR camera, we focus on practice voices and analyse the role of the teacher in terms of primary speech function of offer, command, statement and questions (Holmberg, 2006; Knain, 2015). By focusing on the primary speech functions, it becomes clearer how dynamic the dialogue is between teachers and pupils. Turning our focus to the content involved in the laboratory exercises, we centre our analysis on the practice field and its related sub-categories. Our distinction between practice voices and subject voices is that practice voices focus on the social interaction and dialogue among the teacher, pupils, texts and IR camera, whereas subject voices are the ones that guide the content of the dialogue. (For an in-depth reading on metafunctions and the relationship with variables of practice discourse, see Bergh Nestlog (2012).) Finally, we focus on the interaction between interpersonal metafunction and ideational metafunction corresponding to how the contents are negotiated in the dialogue, which is corresponding to the practice field, i.e. the precondition for meaning-making, which also is the affordance of the different modes. Here we look at coherence and cohesion, which is based on how the different parts of the lessons are connected to each other and how the meaning is tied together by conjunctions and references (Bergh Nestlog, 2012; Knain, 2015).

Table 2. Overview of analysis.

Variables of practice discourse	Analysis	Categories	Metafunction
Practice voice	Speech function	Offer Command Statement Question	Interpersonal
Practice field	Subject content Subject voices Subject textuality	What Who How	Ideational
Practice form	Coherence Cohesion	Conjunction Reference	Textual

Results

Below we present our findings based on the variables of practice discourse, practice voices, practice field and practice form. IR screenshots and transcribed excerpts are provided to illustrate the results.

Practice voices

The practice voice category describes the interaction between the teacher and pupils, between pupils, and between pupils using the IR camera. During the lesson, the teacher (Patricia) used open questions, as seen in the two different excerpts below, to start a discussion about a heat transfer when the pupils discussed how ice melts while in contact with various materials.

Excerpt 1:

Patricia asking open questions

Patricia:

When you put your fingers on these two (teacher pointing to different materials), what did you experience? How did it feel?

Excerpt 2:

Patricia asking open questions

Patricia:

What was your hypothesis? What thoughts did you have?

In contrast, to open questions, the teacher also made use of closed questions as a way to help the pupils to put their laboratory experiences from the experiments into words.

Excerpt 3:

Patricia asking closed questions

Patricia:

Was there any difference when you touched them?

Excerpt 4:

Patricia asking closed questions

Patricia:

Which of the ice cubes did you think would melt first?

During the laboratory work, the teacher sometimes used statements together with an open question. In this way, the combination of an open question and a statement also served as a quick way for the teacher to evaluate whether the pupils had grasped the expected learning goal from the laboratory experiment.

Excerpt 5:

Patricia using statement together with an open question

Patricia:

If we say it like this: They are equal … they have the same temperature. How is it possible that one of the objects feels colder?

(Silence for 4 seconds)

Eskil:

They do not have the same temperature.

Patricia:

They have (example of a clear statement) the same temperature, I say!

In the laboratory manual, the teacher used commands in written form. These kinds of written expressions work as instructions for the pupils during their work with different laboratory exercises. Excerpt 5 reveals how the teacher also used verbal commands when she wanted the pupils to do an experiment.

Excerpt 6:

Patricia using commands

Patricia:

Are there any of you who have not done this with the metal and paper? It is important that you do this (command)! It explains a lot.

Ester:

We have not done it [the experiment].

Patricia:

Come here and look (command), Ester and Josephine.

Patricia starts off by asking a question. However, the question is changed into a command (first command) and is motivated by the next sentence, which emphasises the importance of doing the experiment. The first command is addressed to all pupils, while the second command focuses on pupils who say that they have not done the experiment.

In the category of practice voices, we clearly see a dialogue between the teacher and the pupils where open and closed questions are combined with both statements and commands. In Excerpts 1–4 above, we have not included the pupils’ comments. The focus is instead on how the teacher uses language in the dialogue with the students. In addition to the excerpt above, the pupils interacted with the IR camera during their laboratory work. In Figure 2, the left image is before the experiment, the middle image is during the experiment and the right image is after the pupil has taken away their fingers. A copper strip is to the left in each image.

Figure 2. Left image: Copper and paper strips before putting fingers on them. Middle image: Copper and paper strips when the pupil has put their fingers on them. Right image: Copper and paper strips when the pupil has taken away their fingers.

In this regard, we saw that the IR camera image offered the pupils instant feedback and a visual explanation of what was happening in terms of heat conduction in the experiment (see also Figure 3 and Excerpt 13). The teacher also used the instant IR camera images to address new questions to the pupils about what was happening in the experiment. During the experiment with the two stripes, Patricia and two pupils looked at the image of the IR camera and they discussed what happened when one of the pupils had her fingers on the two different stripes.

Excerpt 7:

The image of IR camera offers instant feedback

Patricia:

Which conducts heat best [of the different stripes]?

Astrid:

The metal

Patricia:

Do you notice [on the image of the IR camera] that this one gets hotter? She [the pupil] give away heat from her body to that one.

By explicitly focusing on the interaction in our analysis of practice voices, we see that questions, statements, commands and offers are involved in the science dialogue. Depending on the choice of speech function, it gives different responses from the students.

Figure 3. Left image: A thermos made by pupils. The yellow stripes are tape and the blue/purple parts are covered with tinfoil. Middle image: A pupil writes the letter H on a desk with an eraser. Right image: Heat radiation on white and black paper. White paper is to the left in the image.

Practice field

Turning the focus towards the subject content involved in the experiments, we now describe our analysis within the category of the practice field. At the beginning of Lesson 2, the pupils started their work by becoming acquainted with the IR camera and its functions. In addition, the pupils almost immediately started to discuss and interpret the IR camera image with each other, and without any interference from the teacher, they related different colours to the temperature scale. The colours of the image are the subject content the pupils needed to understand for the interpretation of the image. The subject content in all six experiments involved heat transfer in terms of radiation and conduction. In addition to heat transfer, two of the experiments (frictions of an eraser on table and dropping a ball on a floor) had a subject content focused on energy (dissipative phenomena of friction). In the experiment ‘How to conserve heat in a thermos', the aim was for the pupils to experience insulation and heat reflection. In the first lesson, the pupils made a thermos using different materials. Some of the thermoses were covered by tinfoil, which created an unexpected IR camera image. Due to the emissivity of tinfoil, it looked like the thermos had a much lower temperature compared to areas that were not covered in tinfoil (see the blue areas on the left image in Figure 3). In the discussion with the pupils during the experiment, the teachers told them that uncoloured metal, such as our example of tinfoil, reflects heat and makes the IR camera image incorrect (see excerpt Table 4).

In the third lesson, the teacher discussed the six experiments together with two of the groups. This type of dialogue is characterised by a clear content focus and the teacher encouraged the pupils to use scientific language in their explanations of the experiments. This type of dialogue is exemplified below, in the excerpts where Frans explains heat transfer from the finger through the china plate to the ice cube, and Ethan and Miriam put their experiences of reflection and absorption from the experiment with heat radiation on black and white paper into words (right image in Figure 3).

Excerpt 8:

Dialogue with content focus

Frans:

I wrote that it [the ice cube] melts faster on the china plate

Patricia:

Mmm. Can you also give an explanation for it? If you think about it. You can say it orally.

Frans:

Because of the heat. That is, the heat on the finger. If you put it there [the finger], it [the china plate] removes the heat from your finger, so it feels colder, but you warm up the ice cube.

Excerpt 9:

Dialogue with content focus

Ethan:

The black paper. It attracts the light [visualised by becoming more yellow than the white paper in the IR camera image], while the white paper puts it away.

Patricia:

Very good, Ethan. If we say it once more and then use some scientific words. What is it called when black paper attracts the sunlight? What is it called, Miriam?

Miriam:

Absorb.

Patricia:

It absorbs. And what is it called when the white … When it bounces out again? Ian [the teacher wants Ian’s attention].

Ian:

Reflects.

As seen in the dialogue between Ethan, the teacher and Miriam, the teacher prompted an answer expressed in scientific terms. Without the visual support from the IR camera image and the interaction with the IR camera, it would have been difficult for Ethan and Miriam to directly experience heat absorption and temperature differences between black and white paper.

Since interpreting the different colours in the image from the IR camera is central for pupils to grasp the subject content of heat and temperature, our next excerpt is an example where the teacher stresses the importance of focusing on the difference between the colours in the IR camera image and the colours’ relationships to temperature.

Excerpt 10:

Relationships between colours and temperature

Arial:

The metal was the warmest, because metal conducted heat better than the paper.

Patricia:

Yes. What was the colour on the IR camera image when it was hot? Which colour, Maria?

Maria:

Yellow.

Patricia:

If it gets warmer. Then it was, Anthony?

Anthony:

White.

We will come back to the reasoning about the relationship of colours (depicted in the IR camera image) and subject voices at the end of this section.

Due to the IR camera’s potential for visualising invisible phenomena, such as heat reflection of shiny metal (Figure 3, left image), it is possible for the teacher to discuss many concepts with the pupils orally. In the excerpt below, we see how the teacher explains the basic idea of a thermos.

Excerpt 11:

Construction of a thermos

Patricia:

Vacuum means that you do not have any air at all. And think like this … Here we have metal and then we have metal [sketching the inner and outer casing of a thermos on the whiteboard]. And here we have nothing [pointing between the inner and outer casing of the thermos on the sketch]. Then … The heat must go … push on molecules. You know. We’ve talked about this before. That I push on a molecule that pushes on a [another] molecule. If there is nothing that can conduct [heat] here [pointing between the inner and outer casing of the thermos on the sketch]. then it [heat] stays there [pointing to the inside of the thermos on the sketch]. Besides this, metal also … has something that is called … that it reflects heat too … stays there [pointing to the inside of the thermos on the sketch]. So the metal is a good heat conductor, although it also reflects the heat. This is a bit mysterious, because you have learned that the metal actually brings out the heat. But in a thermos, then it [heat] remains.

During the explanation of the thermos, the teacher also started to discuss that the metal reflected heat, which was something that the pupils had experienced with the IR camera during the laboratory work. The subject voices are the teacher, pupils and the laboratory manual, but also the IR camera image which conveys subject content to the pupils with the different colours.

When we look at how the subject voices and the subject content are bound together, we focus on the subject’s textuality. Before the colours (as seen on the IR camera image) can be a part of the subject voices and help the pupils to interpret what is happening in the experiment, the pupils have to understand the meaning of the different colours from the projected IR camera image. Before the pupils started to do the experiments, the teacher asked them questions about how to observe temperature with the IR camera.

Excerpt 12:

Relationships between colours and temperature

Patricia:

Do you know what colour … What do you think … What do you see if it [the thermos] leaks? If the heat comes out? Do you know?

By using questions in the dialogue, the teacher helped the pupils to connect the subject content (heat and temperature) with subject voices as colours in the IR camera image.

When the teacher explained the construction of a thermos, during Lesson 3, she sketched a schematic diagram on the whiteboard (Excerpt 11). This diagram helped to link the subject voices with the subject content.

Practice form

In our analysis of the practice form, we look at coherence and cohesion, which means that we study how the different parts of the lessons are connected to each other, and how the sentences in the dialogue are tied together.

In the analysis we see that the topics change during the lessons. At the beginning of Lesson 2, the topic is how the IR camera works and how to take a picture. After a while, when the pupils have learned how the IR camera works, the topic changes, and the focus is on the IR camera image and the meaning of the colours. During the experiments, the focus remains on the images from the IR camera. However, the topic has now changed to heat and temperature and the pupils actually focus on physics. We see that the coherence between the topics is high, which means that there is a link between the IR camera’s function, the IR camera image, and heat and temperature. The IR camera images mediate the subject content.

Lesson 2 is characterised by a pupil-active approach. Instead of having teacher-led instruction, the pupils learn how to use the camera independently. After a short while, when they have understood how to use the IR camera and how it works, the focus changes to the experiments and the results of the experiments. The teacher’s choice of experiments for Lesson 2 is such that the pupils can do them without much involvement from the teacher. During the experiments, the pupils start to carry out their own investigations, such as checking if a person has a fever or writing with ice on the china plate. In the next excerpt, Elvis is doing the experiment with ice on a china plate. When he looks at the IR camera image, he pushes the ice with his pencil and finds that purple stripes appear on the china plate. Also, Eskil looks at the image and tries to write with the ice cube.

Excerpt 13:

Writing with ice on a china plate

Elvis:

It’s really cool. There are purple stripes [on the china plate]. Eskil, look! Look at the camera.

Eskil:

You can write again. May I write?

Elvis:

Wait, I’ll write something. I want to write something … I’ll write … 

The writing on the china plate was not a part of the laboratory manual; instead, the image and the simple treatment of the IR camera may have invited the pupils to conduct their own investigations. The pupil-active approach, both the teacher’s choice of experiment and the work with the IR camera, support the dialogue about the subject content.

During the lessons, the teacher and the pupils did not use any books. The dialogue between the teacher and the pupils is a communication built on the pupils’ experiences from their work with the IR camera. In these instances, the teacher utilises the pupils’ expressions in their conversations and transfers these into a scientific dialogue in the classroom. Before this dialogue, Patricia, Astrid and Asta used the IR camera to see what happens with the heat when Asta put her fingers on paper and copper strips. In the dialogue, Asta connects the result of the experiment with the strips to the experiment with the plates. Patricia uses Astrid’s expression and communicates it into a scientific dialogue.

Excerpt 14:

Communication based on pupils’ experiences

Asta:

That’s why this … Then this should be warmer [connecting to the experiment with the plates by pointing on the plates].

Patricia:

This [a china plate]. If you hold it, this feels cooler, but I promise that they are the same temperature [a china plate and a paper plate].

Asta:

Mmm … 

Patricia:

What do you think you have done with your body heat? What do you think it [the body] has done when you have held this [the china plate]?

Astrid:

It emits. [meaning, spreads it out]

Patricia:

It emits. When I send my heat to it [the china plate], my finger will feel a little colder because I have given away some heat. And this is the reason why this [the china plate] feels colder. Because it conducts heat better. And the metal conducts heat better.

Pupil:

mm

Patricia:

And then it is like this, that this [the china plate] transport heat better than the paper plate.

Astrid:

Then you should eat ice cream on a paper plate.

Patricia:

What did you say?

Astrid:

You should eat ice cream on a paper plate.

Patricia:

Good thinking. Right on the money. I like that [answer and conclusion].

The dialogue, where the teacher uses pupils’ expressions, interconnects the practice voices (use of questions and statement) and the practice field (subject content). In the dialogues, the sentences are often attached to each other, and subject content starts from the known for the pupils and goes to new knowledge. As in the excerpt above, there is coherence in the dialogue, but also cohesion. In the last reply, the teacher used conjunctions and references – ‘and’, ‘because’, ‘this’ and ‘it’ – to tie the pupils’ expressions to the scientific explanation (Table 3). The first parts of the sentences are often the known and the second parts are new information. There is also a connection from the second part of a sentence to the first part of the next sentence.

Table 3. High cohesion in excerpt.

First part	Second part
When I send my heat to it [the china plate],	my finger will feel a little colder because I have given away some heat.
And this is the reason why this [the china plate]	feels colder.
Because it	conducts heat better.
And the metal	conducts heat better.

Conjunctions (bold) and references in sentences (italics).

In the last sentence, new information is given at the beginning of the sentence instead of at the end.

In the next excerpt, the teacher leaves out important information for the pupils, and this makes the coherence low between the sentences. When the teacher uses the words ‘reflect’ and ‘detect metal’, she does not explain what is reflected or that the IR camera can detect painted metal. Also, the cohesion between the sentences is low, because the first sentence does not lead to the second sentence. The word ‘it’ has different meanings in the sentences and this can mislead the pupils’ meaning-making of the concepts (Table 4).

Table 4. Low coherence in excerpt.

First part	Second part
You see, then the metal	will reflect also.
The metal will	mislead us.
It [the thermos]	does not have to leak there.
You know, it [the IR camera]	cannot detect the metal.
It	is more like this, actually.

Also, during the teacher-led lesson, the teacher only said that the metal reflected rays and that the IR camera did not work in this situation.

Excerpt 15:

Low coherence

Patricia:

Those who had tinfoil on the outside [of the thermos]. It was difficult to check yours. Because the rays reflect and then the IR camera does not work properly.

In the dialogues, the teacher used analogies to help the pupils’ meaning-making. The sentences in the analogy in the next excerpt have a common theme with a focus on the china plate, and this makes the coherence in this analogy high. The reference ‘it’ is used in almost every sentence and refers to the china plate. However, in the sentence ‘So, it gives it to the ice’, the reference ‘it’ refers first to the china plate and then to heat.

Excerpt 16:

Using analogy in dialogue

Teacher:

Yes and then it [the china plate] takes … It conducts the heat better. So, it steals the heat from me. Do you understand? And now it takes. So, it gives it to the ice. It’s so kind. It gives the heat.

In the explanation of heat conduction, this analogy makes the china plate become more human, performing an active action.

Discussion

We have in the result used the model of ‘variables of practice discourse' to analyse what characterises the communication and how the contents are negotiated during the lessons. The model guided our focus in relation to the pupils’ dialogues based on the subject content and how the meaning-making is offered to the pupils. In the discussion we revisit our research questions based on the results and previous research. We also discuss educational implications and how the IR camera can support teaching about heat and temperature.

What characterises communication in science teaching targeting the concepts of heat conduction and insulation?

Based on the SFL and variables of practice discourse, we see that the practice field and practice voices are tied together by the practice form. Analysing the speech functions, we reflect on the responses in the dialogues, and how they affect pupils’ meaning-making (Holmberg, 2006; Knain, 2015). The teacher used the primary speech function of offer, command, statement and questions in the communication with the pupils. The teacher often used open questions to the pupils, and this leads to the pupils becoming involved in the discussions. These dialogues started from pupils’ linguistic expression and what was known by the pupils (e.g. Excerpts 8 & 9). This result of using open questions is correlated to what Nygård Larsson (2018) and Tang et al. (2014) found in their studies, emphasising verbal spoken language in pupils’ meaning-making. When the teacher uses offer and statement (e.g. Excerpts 8 & 14), the pupil can accept or question it. These statements are also followed by a question from the teacher, which invites the pupils to the dialogue and support their meaning-making. The significance of the colours on the IR camera images caused few problems for the pupils, and instead of discussions about the meaning of images we found that the images also offered the pupils discussions with a focus on the subject content. Because of the changing colours on the IR camera images during an experiment, this provided an opportunity for the pupils to see the instantaneous change that takes place in the experiments (see Figure 2 and 3). Without the IR camera, this would have been difficult for the pupils to detect. These instantaneous changes in the IR camera image were also the focus of the teacher’s dialogue with the pupils.

Our findings indicate that pupils manage to represent heat as a process and that the IR camera serves as a shared point of attention (Schoultz et al., 2001) in both visual and verbal communication. The language the pupils and the teacher use indicates that the discourse around heat and temperature is dynamic. In the dialogues, the teacher uses pupils’ expressions and experiences of heat and temperature in the explanations of the experiment. For example, the teacher uses analogies based on the pupils’ experiences in their meaning-making process. In addition, as a way to make meaning of the involved physical concepts, heat and temperature, the teacher explicitly makes use of different kinds of resources and semiotic modes, both in combination with and without the IR camera. The IR camera as a semiotic resource provides a visual support for thermal conductivity and heat flow, and the images seem to facilitate discussions where dialogue, and the subject voices, are in focus. This, together with the practice form, creates an opportunity for the pupils’ meaning-making.

In what way is meaning-making offered to the pupils in their work with heat conduction and insulation?

The results of this study indicate that the IR camera image helps the pupils to observe and understand concepts connected to heat and temperature, and this is in alignment with previous research (e.g. A, B, C and D). The images, together with the dialogues, seem to help the pupils in their meaning-making. In the dialogues, the teacher and the pupils talked about temperature as different colours, based on what they saw in the IR camera image. The instant feedback and visual explanation, together with the pupils’ expressions of what they saw, were the starting point in the dialogues. Based on what the pupils saw on the image and their interpretations, the teacher used these to help pupils in their meaning-making and encouraged them to use scientific language.

In dialogues the teacher used open questions to start a discussion about, for instance, heat transfer. Based on the result of coherence and cohesion, we found that pupils’ work with the IR camera, together with the dialogues with the teacher, helps pupils to understand concepts of heat and temperature. The images help pupils to see how heat transport is different in different materials, that heat is transferred from a hot to a cold object, and also how insulation can prevent this. The visualisation made by the IR camera, also initiated discussions about why a china plate feels colder than a paper plate. This result indicates that the interpretation and understanding of the science content are stimulated both by the images and the dialogues, and not only by the images (Erickson & Tiberghien, 1985). The images of the IR camera seem to demystify heat transport for the pupils, and the visualisation is a shared point for their discussions (Haglund et al., 2014, 2015; Jeppsson et al., 2017; Xie & Hazzard, 2011).

The work with the IR camera and pupils’ experiences of the experiment ‘How to conserve heat in a thermos’ allows teachers and pupils to notice how a real thermos is constructed, and why they have a shiny inside. However, our findings indicate that the pupils’ meaning-making of how shiny metal reflects heat and heat radiation has failed, due to the low coherence and cohesion in the teacher’s explanation. The content, heat radiation and heat reflection, has a high level of abstraction, and the pupils’ prior understanding may have been low. This can lead to the pupils simply accepting the information from the teacher as truth, with little understanding of the content. To interpret the visualisation of heat radiation and heat reflection, the pupils probably had to have prior understanding of the content, and this result is in line with previous research (Schönborn et al., 2014).

Educational implications

In this study we have looked at what happens in the communication and meaning making when an IR camera is used teaching heat and temperature. The results illuminate the role of technology-enhanced visualisation in science education and how it can stimulate communication in the science classroom, which could help practitioners to facilitate learning of complex phenomena. The work with the IR camera and the illustrative images seems to facilitate a communication based on pupils’ direct contact with the perceived phenomena. Hence, the interaction with the IR camera may be used either as a starting point in classroom dialogue or as a unique visualisation tool in its own right in laboratory work. In the study, we see that the experiment ‘How ice melts while in contact with various materials such as paper and china plates’ is confusing when it comes to temperature, because the china plate feels colder than the paper plate. Using an IR camera for pupils in Grade 6 of primary school seems to have a positive impact on the work with heat and temperature, and on pupils’ understanding of heat and temperature. The pupils did not have a problem using the IR camera and interpreting the IR camera image. The IR camera image also seems to invite the pupils to carry out their own investigations, which makes them active during the second lesson. The instantaneous changes of the IR camera images encouraged the pupils to check if a person had a fever, to write with ice, or to see what happened when they looked at a window.

In this study, we have seen what characterises communication in science teaching, when an IR camera is used in lessons. If an IR camera is to become a useful semiotic resource, the teacher needs to see the didactic advantages it offers. An investigation of how teachers express the didactic advantages and disadvantages of working with an IR camera would be an important research field.

Acknowledgements

We would like to add an acknowledgement: We would like to thank the participants in the study. Further, Linnaeus University for their financial support to this research project and we are grateful for useful comments and suggestions from our colleagues. In addition, we much appreciated the helpful comments on this manuscript and suggestions for complementary references from three anonymous reviewers.

Disclosure statement

No potential conflict of interest was reported by the authors.