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Evaluating the impact of demonstrations in the teaching and learning of chemistry
Author
Mohamed Azman Mohamed Selamat
Supervisor
Subramaniam, R. (Ramanathan)
Abstract
This study is an attempt to add on to the scant knowledge of how demonstrations can be used in a chemistry lesson. The study was carried out in a government-funded school in Singapore. Studies involving the use of demonstrations as an effective approach have not been able to clearly make a stand on their impact on students‟ learning. Some of the findings were highly critical of the use of demonstrations while others encourage the use of demonstrations. In this study the use of the demonstrations is revisited.
In order to determine the effectiveness of the demonstration lessons, two evaluative instruments were developed to assess its impact on students‟, both cognitively and affectively. The cognitive assessment uses a four-tier multiple choice questions (4TMC) instrument, which is a new tool to be used for this kind of study as it is intended to address a weakness of the two-tier multiple choice questions (2TMC). The additional tiers to the 2TMC are used to measure the confidence ratings of the students to the answers they gave for each of the first two tiers, which consist of a tier that measures the students‟ content knowledge and another tier which assesses the students‟ explanatory knowledge.
A pre test/ post test approach was used to measure the students‟ understanding. The gains in the scores were used to determine if there was a significant difference between the treatment and the control groups. The instrument was administered to 148 upper secondary students who take Chemistry as one of the Science subjects offered at the General Certificate of Education at the Ordinary Level. The chosen topic on acid-base reactions is a popular and important topic in the GCE „O‟ Level examinations.
It was found that the effect of the treatment was not significantly different from the effect of traditional teaching in the Answer tier. As for the Reason tier, there was a significant difference observed for the treatment group due to the demonstrations. There was also significant effect of the treatment on both the males and females in the treatment group.
The utilization of confidence ratings has allowed us to observe effects not detected by traditional tests. This has led to the insight that traditional teaching may have caused the students to develop undesirable or wrong concepts in the understanding of the topic. The treatment has been able to keep the confidence of those who obtained wrong answers low. Looking at the analysis of the gains in confidence ratings for the reason tier, it was observed that for the control group, the increase in confidence of the students in getting the wrong answer has increased significantly as compared to that of the treatment group. Thus also holds when both tiers are considered together as well.
The use of demonstrations was also seen to reduce the effect of misconceptions. In fact, for the A and B tiers, it seems to even benefit students from the treatment goup as it helps them to have a better understanding of questions which stems from higher order thinking skills.
The use of confidence ratings in identifying alternative concepts (ACs) has also led to the finding that through traditional teaching, instruction may lead to ACs. Due to the exploratory and reflective nature of the demonstration lesson, it seems to be able to reduce the effect of ACs. Through use of confidence bias (CB) it has been possible to determine which group had actually been more positively influenced by the intervention. Form the data obtained the treatment group showed a significant improvement in the students‟ understanding after the intervention.
The survey findings are also very encouraging. The students found the lesson engaging as the questions asked during the demonstrations challenged them. They also found that the lesson was a refreshing change from the traditional teaching method.
In order to determine the effectiveness of the demonstration lessons, two evaluative instruments were developed to assess its impact on students‟, both cognitively and affectively. The cognitive assessment uses a four-tier multiple choice questions (4TMC) instrument, which is a new tool to be used for this kind of study as it is intended to address a weakness of the two-tier multiple choice questions (2TMC). The additional tiers to the 2TMC are used to measure the confidence ratings of the students to the answers they gave for each of the first two tiers, which consist of a tier that measures the students‟ content knowledge and another tier which assesses the students‟ explanatory knowledge.
A pre test/ post test approach was used to measure the students‟ understanding. The gains in the scores were used to determine if there was a significant difference between the treatment and the control groups. The instrument was administered to 148 upper secondary students who take Chemistry as one of the Science subjects offered at the General Certificate of Education at the Ordinary Level. The chosen topic on acid-base reactions is a popular and important topic in the GCE „O‟ Level examinations.
It was found that the effect of the treatment was not significantly different from the effect of traditional teaching in the Answer tier. As for the Reason tier, there was a significant difference observed for the treatment group due to the demonstrations. There was also significant effect of the treatment on both the males and females in the treatment group.
The utilization of confidence ratings has allowed us to observe effects not detected by traditional tests. This has led to the insight that traditional teaching may have caused the students to develop undesirable or wrong concepts in the understanding of the topic. The treatment has been able to keep the confidence of those who obtained wrong answers low. Looking at the analysis of the gains in confidence ratings for the reason tier, it was observed that for the control group, the increase in confidence of the students in getting the wrong answer has increased significantly as compared to that of the treatment group. Thus also holds when both tiers are considered together as well.
The use of demonstrations was also seen to reduce the effect of misconceptions. In fact, for the A and B tiers, it seems to even benefit students from the treatment goup as it helps them to have a better understanding of questions which stems from higher order thinking skills.
The use of confidence ratings in identifying alternative concepts (ACs) has also led to the finding that through traditional teaching, instruction may lead to ACs. Due to the exploratory and reflective nature of the demonstration lesson, it seems to be able to reduce the effect of ACs. Through use of confidence bias (CB) it has been possible to determine which group had actually been more positively influenced by the intervention. Form the data obtained the treatment group showed a significant improvement in the students‟ understanding after the intervention.
The survey findings are also very encouraging. The students found the lesson engaging as the questions asked during the demonstrations challenged them. They also found that the lesson was a refreshing change from the traditional teaching method.
Date Issued
2011
Call Number
QD40 Moh
Date Submitted
2011