Comprobación de las limitaciones de la concepción

Theme 4 of research sub-question 2: Teachers drew on learner experiences by using resources, examples and language familiar to learners as useful tools to facilitate conceptual understanding.

Incorporation of learners’ socio-cultural practices, experiences and beliefs in some NS topics encouraged teachers to create partnerships with community members and facilities such as clinics and resources that provided learners with access to knowledge and experiences that extend and complement learning experiences in a science classroom. This theme is addressed in the lessons that were observed during laboratory work to construct a model of a cell using readily available resources and sections of the respiratory system and blood circulatory system. Some of the information on the use of learners’ experiences and learners’ home languages was drawn from interviews done after the lessons.

4.3.5.1 Laboratory work to construct a model of a cell using readily available resources

During laboratory work, teachers designed activities that were appropriate for their group of learners by using resources readily available in the home. As mentioned in 3.4.2, the schools were all non-fee paying schools and hence depended on government support in terms of resources. Consequently resources were very scarce. For instance, in an activity from the learners’ textbook which required learners to use gelatine to make models of a general structure of a cell, Thuli and Nhlamulo tasked learners to prepare models using resources that were readily available in the home and surroundings as seen in Figure 4.5 below.

This particular laboratory activity required learners to use chemicals like gelatine and devices such as refrigerators which were not available in their laboratories. The learners were not disadvantaged; instead, they used seeds, plant leaves, buttons, wool, needles, mealie-meal, different types of sweets and cardboard boxes which are all items found at home. As a result, learners could manipulate the materials easily because of familiarity. In this way, the teachers provided opportunities for experiential learning through hands on activities despite the poor economic status of their schools and learners.

Figure 4.5: Examples of models of general structure of a cell constructed by learners

Models of animal cell made using maize seeds, buttons and cotton thread

Models of animal cell made using plant leaves, grass and electric conductors

4.3.5.2 Use of an analogy to teach blood circulatory system

In a lesson on blood circulation, Nhlamulo asked learners about their socio-cultural practices or beliefs that are associated with blood and its movement in the body. Many learners pointed out that they had witnessed the slaughtering of animals such as goats for rituals and the blood used to cleanse any evil spirits in the home and family. Nhlamulo questioned how blood can perform such a function. One learner said: ‘Sir, blood is stored in the heart and the heart is full of love.’ Other learners laughed but some believed him and added that smearing blood around the home is like spreading love which repels evil. It shows how learners try to explain their cultural practices using common sense. This was complicated by a learner who pointed out that a ‘sangoma’, meaning a traditional healer, once smeared blood on his older family members in order to scare witches away and others said that it was meant to give them strength. These learners viewed blood as a sacred substance, due to their socio-cultural practices and beliefs.

Nhlamulo asked those learners how blood can transport oxygen which is required by all body tissues if it is stored in the heart. In reaching out to learners, Nhlamulo drew on learners’ everyday experience when he used an analogy to explain the movement of oxygenated and deoxygenated blood in the human blood. Analogies help learners relate the scientific concepts learnt to familiar and relevant experiences and knowledge, which enables them to explain and understand the concepts. This is what the teacher said:

Nhlamulo: You see we have roads, streets and paths where we walk and drive our cars, the same applies in the circulatory system, the veins and arteries are the roads and streets. We have roads where cars move in one direction and the others move in another direction. The same applies to deoxygenated and oxygenated blood which moves in different blood vessels.

These were some of the learners remarks: ‘Ooh that’s it’ ‘Yes that makes it clear’ to show that the analogy had made it easier for them to understand the circulatory system. Nhlamulo jokingly said: ‘Though blood is such a magical substance as indicated by some of your experiences, it is still a medium of transport in our bodies.’ It shows that certain concepts are abstract for learners to conceptualise, so using examples familiar to them enhances learner understanding. Analogies could also dispel some of the socio-cultural beliefs

learners hold which can impede the acquisition of proper scientific concepts. The analogy used drew on an experience that most learners are familiar with, the roads and stream of vehicles travelling on the same road in different directions and carrying different people and goods.

However, it should be noted that this analogy helps learners when the sole purpose is just to demonstrate the element of direction of flow of blood and the need for blood vessels. It also demonstrates that as blood circulates it carries different components just like there are cars, buses and even motorcycles moving along the same highway. However, learners may end up thinking that oxygenated and deoxygenated blood carry the same substances just like the roads have generally similar vehicles. Learners may also think that blood movement stops at certain points in the vessels like what happens with cars at robots. Nothing is also said about the need for a pumping mechanism that makes the movement continuous and in this case, the place of the heart in the circulation system.

In order to make sure that the learners correctly connect the circulatory system to the system of vehicles on the road Nhlamulo asked learners to identify features in the road system that correspond with those in the circulatory system. The learners shared information in pairs. One pair asked: ‘Sir what does the driver in the cars represent?’ Nhlamulo threw the question back to the class and one learner answered: ‘It is the heart.’ This meant that there were many hearts in the human body, a misconception which some learners would carry away unless it was addressed. Failure by teachers to appropriately lead learners to analyse the analogy and concept may result in learners misunderstanding the concept being taught. Through discussions, the teacher and the learners later agreed that the driver in each vehicle is like the force in each blood vessel which causes movement of the vehicle and goods, in the same way that there is force that propels blood throughout the blood vessels. It was important for the teacher to explain to the learners that an analogy helps to understand some aspects of the concept but not all.

4.3.5.3 Use of learners’ home languages in science teaching and assessment

Table 3.2 shows how the three schools were designated by the DOE according to the African languages taught in the schools as IsiXhosa, Sipedi and Sesotho School, IsiZulu,

IsiXhosa and Sesotho School and Setswana, Sesotho and IsiZulu School. Though Thuli is Sepedi, Peter IsiZulu and Nhlamulo Tsonga (Table 3.1), they had learnt to speak their learners’ languages over the years. In one school, learners of the same ethnic group were placed in the same class and this made it easier to code switch from English to one African language than to all three for the purposes of explaining a science concept when teaching. Code switching is ‘the use of more than one language in a single speech act’ (Setati, 1998: 34). Teachers were observed explaining scientific concepts in both English and the learners’ home languages. Teachers’ repetition of the scientific concepts in both languages enables learners to understand the scientific concepts better (Lim & Presmeg, 2011).

According to the teachers, code switching was very important. For instance, Nhlamulo asserted, ‘It helps me in explaining using their home languages since most of the learners do not understand much English’. The researcher observed learners freely communicating in their home languages during group discussions. However, when giving feedback to the class or answering the teacher’s questions, learners were encouraged to use English even though they could not speak the language well. In a post-lesson interview, the teachers pointed out that it was a classroom rule which was meant to help the learners practise communicating in English as it is the medium of instruction and assessment.

In interviews done after the lessons, teachers acknowledged facing challenges in explaining concepts in learners’ home languages as some scientific terms are not readily available in those languages. Examples mentioned included processes like melting and smelting which can be translated by the same word ‘ukhuncibilika’ in Zulu and Xhosa. The words ‘define’ and ‘explain’ can both be replaced by one word ‘chaza’ in Zulu. In such situations, the teachers resorted to using examples in learners’ everyday experience to bring out the meaning. Below is an example where one teacher mentioned to differentiate melting from smelting:

Nhlamulo: I would ask them what happens with the ice they buy from the school tuck shop when they put it in their mouths. As for smelting, there are several people who weld around making burglar bars. I would ask them how those

The research findings show that inasmuch as the teachers had mastered speaking the learners’ different home languages, there remain certain scientific words and processes that could not be described or explained in any language other than in English without distorting the meaning. This is evidence of the limitations of vernacular languages in science teaching. One teacher lamented the language barrier in his classes when he said:

Nhlamulo: I remember last year, despite discussing in class that the purpose of reproduction is to make sure the species does not become extinct, some learners were adamant that it’s meant to grow their surnames, meaning having more members of the family.

In the teacher’s view, learners were unresponsive to what he had taught them about reproduction in humans. An analysis of learners’ responses reveals that the learners encountered difficulty in using scientific terms. The teacher also confirmed that the learners meant that reproduction results in the increase in species. If the teacher had clearly explained to the learners the similarities between what the learners believed and the scientific reason the learners might have adopted a scientific way of explaining the importance of reproduction. Therefore teachers should conceptualise learners’ experiences and reasoning and then guide them to positively explain the scientific concepts.

In one of the lessons, the researcher observed one of the teachers, Peter, administering a test. Of interest was a micrograph of an animal cell (Figure 4.6) where learners needed to provide labels for the parts numbered 1-5.

Several learners raised their hands and one learner asked in her home language whether they were supposed to draw the cell. The teacher elaborated what the question required in English and then he asked them to read the instructions carefully. He again translated the question in Sesotho as it was the language of all learners in that class. It turned out that the other learners also wanted to ask the same question. It can be deduced that the learners did not realise the importance of reading and understanding the questions and the instructions carefully before attempting to answer.

Another reason could be that these learners did not understand the question due to poor understanding of the English language, which is the medium of testing. This is different from the teaching and learning process where the teacher could explain the concepts in the vernacular language where possible. In a test the teacher cannot go question by question translating them into the learners’ home language. This could be a challenge to the teachers and learners during examinations as there is no room for any other language and this can result in poor performance. There is a discrepancy between what happens in class and the testing in terms of language. It can therefore be concluded that, inasmuch as code switching helps learners to understand the concepts, the problem arises in situations like tests or examinations. One of the teachers pointed out that to avoid such situations, she makes it a point that her learners should always try to answer the questions in English during the lessons.

4.3.5.4 Teaching contraceptives using community members and resources

In the interviews done before lessons, teachers were asked if there were any community members, structures or facilities that they could use as resources to teach science. The results showed that teachers used the community in various ways and sometimes they were not aware that they were involving the community. For instance, asking learners to get information from their parents was one common way of involving the community in the teaching of science. Thuli mentioned that at one point she gave learners a project on contraception where they were required to choose one source of contraception and research on how it works and its side effects. In other words, they were supposed to get as much information as possible from different sources.

The teacher had to write a letter to some of the community members such as nurses at a local clinic so that the learners could be assisted, as initially the nurses had declined to provide the information. This also applies to a few learners who approached other community members to discuss the traditional methods of contraception. The teacher pointed out that not much information was given to the learners by the adults who knew the methods. Community members take children as their own; hence they wanted to ascertain from the teacher that it was part of a school science project as they were worried that the learners were already sexually active. This is an African traditional tendency by adults to consider every child as one’s own and be willing to offer protection. Possibly there could be some element of patent rights issues as well where the traditional knowledge bearers needed the teacher’s acknowledgement of their knowledge.

When Thuli asked learners about the information learners got from their parents regarding the project on methods of contraception, learners revealed that it was not possible to discuss such matters with their parents.

When asked about the same question on whether he uses community members in his teaching, Peter said: ‘No I have not heard of them and if they are there, they have never come forward to offer any assistance.’ From such a response, one can infer a sense of unwillingness on the part of the teacher as he is the one who should initiate community involvement and not the other way round. The teacher, however, mentioned that there was a local Bible college which not only focused on Bible matters but also on developing the community in total through the provision of extra science classes to learners. The college had also established a community public library. Peter and Thuli mentioned that the local university campus offered extra science classes and practical laboratory work every Friday afternoon and Saturday morning to the learners in the locality, though the unfortunate part was that most of the learners could not afford the fees that the university charged.

The results presented in the section show that teachers drew on learner experiences by using resources, examples and language familiar to learners as useful tools in their teaching in an effort to facilitate conceptual understanding. Teachers’ PCK was apparent as they managed to devise and deploy the pedagogical resources appropriate to teaching such concepts and

also to draw upon general pedagogical theories and take into consideration the constraints imposed by their teaching context (Park & Oliver, 2007).