What are Grade 11 Physical Science learners’ conceptions and experiences of the topic light before and after an ASEI-PDSI teaching intervention was implemented
As reflected in the findings from the questionnaires, there was indication that most learners perceived topic light as an important topic. They indicated that it is important for them to learn about light in school with the view that light plays important roles in their daily life. The findings o f the questionnaire further revealed that learners had a positive attitude and willingness towards the topic
Based on their prior knowledge, learners indicated the necessities o f learning topic light in relation to their daily life experiences. It is regarded by Mukawambo (2012) as important to integrate and recognise learners’ prior everyday knowledge and experiences in engaging learners into new situation. The findings from questionnaires revealed that learners’ interests o f the topic light are influenced by their prior knowledge. M eyer (2004) appreciates what learners already know and develops learning experiences that provide them with opportunities to use their knowledge to accommodate new skills and scientific knowledge for better understanding.
Furthermore, the learners’ responses from the questionnaire indicated that they were able to link the science concepts to natural phenomenon. This was an indication that learners used their prior knowledge to link classroom science to natural phenomenon. Although learners’ responses from questionnaires had shown that they recognised the importance and uses o f light in everyday life, the pre-test results were clear that learners had little scientific experiences o f the topic light. The results from the pre-test learners scores indicated that only 13.6% o f learners reached 50% and above.
Research sub-question 2:
How does an ASEI-PDSI teaching approach influence Grade 11 Physical Science learners’ conceptual understanding of the topic light?
After the ASEI teaching approach intervention, learners’ conceptual understanding related to the topic light improved significantly. This is reflected in Table 9, as post-test results show an increase by 27% shifted from 35% in the pre-test to 62% in the post-test. These findings support Rotich and Mutisya (2013), who confirm that ASEI-PDSI is a possible development in science as it gives learners an opportunity to explore and satisfy their curiosity. In the post-test, most learners chose the correct answers in most questions and their explanations o f their answers indicated sense-making o f the topic
light.
The ASEI teaching approach created a positive shift in terms o f learners’ sense making and knowledge construction. This was reflected in learners’ responses during the lessons when they were expected to make several observations and respond to several questions.
Research sub-question 3:
What factors enable or constrain Grade 11 Physical Science learners to make sense of the topic light?
The findings o f this study revealed that practical activities and an inclusion o f learners’ prior knowledge are some o f the factors that enabled learners’ sense making o f the topic light. ASEI-PDSI
is a teaching approach whereby learners are actively involved in practical activities during the lesson. In the context o f this study, the practical activities enabled learners to confirm the outcome o f their observations and they were also able to correct their misconceptions.
Before the practical activities, learners were always asked to make their predictions o f what could happen and later they confirmed their observations empirically. It was evident after each practical activity lesson that most learners managed to draw mind maps showing the correct scientific concepts that emerged from each lesson. In addition to the practical activities, the findings o f this study revealed that learners’ prior knowledge enabled them to make sense o f the topic light. During the ASEI teaching, for instance, learners’ prior knowledge was used as a starting point as well as throughout the lesson. It was based on their prior knowledge that the teacher built on the whole lesson as proposed by Kasanda et al. (2005),who emphasize the need to use learners’ existing knowledge/skills and include learners’ everyday experiences in order to introduce a topic.
As a result, the findings revealed that learners were able to link classroom science to natural phenomenon such as lunar eclipse, solar eclipse and rainbow. There was also evidence that learners used their prior knowledge to correctly explain how the reflection o f light is used in various industries such as fishing, mining, construction and transport.
Although prior knowledge was identified as enabling sense making, the research findings also revealed that prior knowledge on the other hand constrained sense making o f the topic light. Learners had several misconceptions about light which were influenced by their prior everyday knowledge. For example, learners had misconceptions that only shiny objects such as a mirror and silver plate are able to reflect, while objects such as wood cannot reflect light. Learners also believed that shadows and images are scientifically similar.
The research findings also revealed that the LoLT is another factor that constrained learners’ sense making o f the topic light. In the context o f this study the LoLT was English as second language. There were wrong spellings o f scientific words in some learners’ responses in the pre-test. Such spelling mistakes were influenced by learners’ English proficiency as they did not recognise that their spelling o f concepts made the whole sentences to be senseless in such a way that they could not be understood scientifically.