Thandi was observed teaching the topic: ‗Atoms and Compounds‘. While she was teaching, she used both everyday words as science concepts and everyday words in science context. Of the words used I noted the everyday words used in science context. Table 5.3.2.1 shows the everyday words in science context used by Thandi during her observed lessons.
Table 5.3.2.1 Summary of everyday words used in science teaching during Thandi‟s lessons
Everyday words in science
Pure Matter Properties
Scale Chain Levels
Reading Reaction Conductor
States Lattice Charge
Balancing Regular Phases
Action Held Model
Transformation Method Occupy
Moment Inert
Out of the identified list of everyday words used by Thandi during her physical science lessons, five everyday words have been selected to show how these words were used in the context of the observed classroom lessons and whether these words were explicitly, implicitly or not interpreted according to context of use. Table 5.3.2.2 shows the five selected everyday words during Thandi‘s physical science teaching.
What transpire from Table 5.3.2.2 is that the teacher assumes meanings of everyday words used in science context to be obvious to the learners, without paying attention to other contextual use of the same word and how it differs or relate with science contextual meanings?
121 Table 5.3.2.2. Contextual use of some everyday words in science teaching during Thandi‟s lessons
Mediation
EWS
Teacher excerpts
Explicit mediation
Matter What do you understand by matter? Learners responded in a group and
they were inaudible to be captured.
Teacher: Anything that can be able to occupy a space and has mass, when you see that thing is matter from the previous knowledge, from grade 7.
Non-mediation Reaction When they say hydrogen react with any element, when you write that hydrogen symbol, it must have 2, it‘s a golden rule.
Non-mediation Phases
Then matter has got its classifications, phases, Thabo (not learner‟s real
name) can you give one phase of matter, maybe just to remind you there
are three phases of matter….(no response) lets assist Thabo. Yes solid is one phase of matter, solid. Thabo can you give us an example of a solid, its fine take time I will come back to you, eg. Diatomic or binary, DI, its not die but di and bi BI, what does this two means…? Bi, di… what does this mean (silence). Di means (learners finished and said ONE) di means one (teacher probing further)… learners showing mixed answers, whether 1 or
2… two (the teacher says). Mono means one, then binary, di means two,
for example, eg we‘ve got seven binary molecules or binary atoms.
Zama (not learner‘s real name) can you give us three phases of matter, the three phases of matter that you studied in grade 7, grade 8, you can call them phases or states there are three. Zama!
Zama: metals, semi-metals and non-metals (the teacher was saying these
after the learner)
Teacher: Metals, semi-metals and non-metals, three phases of matter, it‘s a try akere (isn‘t) and what I like with that he gave science answers not give us ehhhhh technology answers or maths answers. Phases of matter…(the teacher pointing at another learner without clearly telling
learners whether the first answer given by Zama is correct or wrong for the question she is asking)
Non-mediation Model How can we represent these compounds, we‘ve been talking about
compounds, compounds, compounds can be represented in two ways, we can use ehhhm ehhhm a method which is called a ball-and-stick model, …..silence….what do we call this model? The teacher responding together
with learners: a ball-and-stick model. The other one is space filling model.
Implicit mediation
Transformation
Learner: we can classify water into solid when it turns to ice, and when
water is boiled the vapour…(incomplete) and when you smell, melts
Teacher: its transformation, when you take the same water which you said it is liquid you put it in a refrigerator, in the deep freezer, it freezes, it changes from liquid to solid. And when you want to reverse the ice to liquid what do we call the process we did it in the first term? Precious!
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5.3.2.1. Thandi’s usage of the word ‘Reaction’
The word reaction has varying meanings according to its contextual use and it is necessary that the meanings are made known according to a specific context where the word is used. Stevenson and Waite (2011) explain reaction as something that you do, say, or think as a result of something that has happened (situational context); it refers reaction to a change in people‘s attitudes or behaviour caused by disapproval of the attitudes of the past; it refers reaction to a response by the body, usually a bad one, to a drug and chemical substances (biology context); and also refers reaction to the ability to move quickly in response to something, especially if in danger. In the chemistry strand of physical science, reaction often refers to a chemical change produced by two or more substances acting on each other (chemical reactions or nuclear reactions) while in physics strand of physical science, reaction refers to a force shown by something in response to another force, which is of equal strength and acts in the opposite direction (Stevenson & Waite, 2011). During the classroom teacher talk, reaction was used as follows: “When they say hydrogen react with any element, when you write that hydrogen symbol,
it must have 2, it‟s a golden rule”.
The teacher used react (verb) instead of reaction (noun denoting a chemical process) and its meaning was not explicitly explained to the learners. When further probed if there was anything she wanted her learners to know about reactions and about what she meant by reactions during her lessons, Thandi said:
Not necessarily, but when we talk about reactions with my learners maybe taking one element reacting it with another, it will give us or yield a certain product but we have others which cannot yield any, when Sphamandla I can‟t even give you the correct answer, but what I normally use is that when I react elements of this group, then that one they will give me this. That particular product, maybe from there you balance but maybe sharing it with learners, so that I can come to an understanding…
Firstly, the teacher clearly state that there was nothing she wanted her learners to know specifically about reactions, because she seems not to know what reaction means in the context of science and this is mentioned in this response ―… I can‟t even give you the correct answer…” of what reaction means in science context. This is distressing because the meanings of reaction changes across and within physical science contexts, because in physics reaction is a technical term but in chemistry reaction is an EWS used to describe what happens when two or more substances are mixed (Oyoo & Semeon, 2015). Furthermore, Oyoo (2012) concurs that when
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words such as reaction are used within the science context they embodies certain concepts that are important to the processes of teaching and learning specific chemistry content within physical science. So lack of understanding and explicit explanation of reaction could be a barrier into learners learning of science concepts embodied in reactions. In addition, the teacher seems to associate the word reaction to products, even though there is no clear indication of how the two were compared.
Lastly, due to teacher pronunciation and the fast teaching pace, some words were not clearly articulated or were said swiftly. For example, when referring to reaction the teacher (Thandi) spoke of ‗action‘ instead of ‗reaction‘ as follows: “…molecular electrons are shared between the
non-metals while in ionic they are solid that results from action of metals and non‖. The word
action is what was captured during the teacher‘s classroom teaching, and if captured properly it can mislead the learners in understanding reactions since action and reaction have different meanings and implications in learning science.
5.3.2.2. Thandi’s usage of the word ‘Phases’
In one classroom observation, Thandi used the word ‗phases‘ to refer to themes of matter, but initially the word phases seems to have been used similarly with classifications. This can be seen for example during Thandi‘s lesson when she said:
Then matter has got its classifications, phases, Thabo (not learner‟s real name) can you give one phase of matter, maybe just to remind you there are three phases of matter….(no response) lets assist Thabo. Yes solid is one phase of matter, solid. Thabo can you give us an example of a solid, its fine take time I will come back to you.
The word ‗phases‘ seems to have not been explained according to its context of use and this might have implications on learners learning of the physical science content. The word phase when said quickly, as was done during teaching, might be mistaken to its homophonic word ‗face‘, especially when this word (phase) is not written down or it is the first time the teacher talks about it in class. Interestingly however is how the teacher explained the following words (homonyms) yet the word phases (which sound like faces) was not fully engaged with.
eg. Diatomic or binary, DI (pronounced as die), its not die but di and bi BI, what does this two means…? Bi, di… what does this mean (silence). Di means..? Mono means one, then binary, di means two, for example, eg we‟ve got seven binary molecules or binary atoms.
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Thandi chooses which words to explain during teaching and more often those words associated with what science knows are the ones enjoying explicit interpretations during most of her lessons. Lack of teacher‘s explicit interpretation of the word ‗phases‘ might not lead to holistic and effective learners learning of the content, because the word have different contextual meanings which learners might come into class with. The everyday meanings of the word phase differ according to the context of the word usage. For example, Stevenson and Waite (2011) refer to phase (noun) as a stage in a process of change or development; phase (verb) refers to arranging to do something gradually in stages over a period of time. These everyday contextual meanings are important to be kept in the teacher‘s mind during the teaching of ‗phases‘ of matter.