Browsing by Author "Samarasekere, P.W."

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An Initial Study on Understanding the Effect of Question Surface Features on Students' Responses
(In: Proceedings of the International Postgraduate Research Conference 2017 (IPRC – 2017), Faculty of Graduate Studies, University of Kelaniya, Sri Lanka., 2017) Rupasinghe, T.P.; Samarasekere, P.W.; Wijesinghe, S.
Assessment is one of the key feedback mechanisms in measuring the effectiveness of the teaching and learning process of science education. One of the challenges in evaluating through the assessments is that students often focus on surface features of the questions such as the length, vocabulary, or the phrasing, rather than on underlying scientific principles of the question. According to educational theories, the wording of the questions has a substantial impact on the students’ performance during the science examinations. However, in the current science education context, there is only a limited number of research studies available which provides an insight into the relationship between students’ performance and the question features. The objective of the current study is to investigate the effect of the surface features of the questions on students’ performance. Herein, we have investigated how wording of an examination question could affect students’ performance. The study was conducted as a part of the Chemistry for Technology course (sample size =86) at the Faculty of Computing and Technology, University of Kelaniya, Sri Lanka. At the final examination, two different types of constructed-response questions were given to students. One was a Direct question which included solving a question using a basic chemistry concept and simple arithmetic calculations. Second version (Wordy question); included the same data as in the Direct version but with a related scenario. In the Wordy question, students had to go through several sentences to pick relevant data to solve the problem. It is expected that, the scenario given in the Wordy version could lead to a deeper understanding of the question and thereby result in better students’ performance. Marks obtained for the two versions were averaged and compared to investigate whether there is any significance of the wording towards the performance of students. Average mark for the Wordy question yielded to be 43% while that of the Direct question was 63%. Moreover, the attempt rate (no of student who had attempted) was significantly low as 39% for the Wordy version of the question. According to the performance of the students it was clear that the students meet a considerable difficulty in the understanding the Wordy questions. It can be concluded that the use of items such as syntactically complex sentences in examinations could decrease the performance of the students. Moreover, significantly lower attempt rate observed in the case of the Wordy questions suggests that the students tend to skip lengthy questions even without trying to identify the basic scientific principle lying behind. Hence it can be concluded that the surface features such as the length, type of words can play a key role in students’ performance at the examinations. Currently, further studies are being conducted to gain more insight into this.
Inquiry Based Learning Approach in Introductory Level Science Education.
(In: Proceedings of the International Postgraduate Research Conference 2017 (IPRC – 2017), Faculty of Graduate Studies, University of Kelaniya, Sri Lanka., 2017) Rupasinghe, T.P.; Samarasekere, P.W.; Wijesinghe, S.
In today‘s world, science education has been shifted from the traditional ―Passive Learning‖ to the ―Active Learning‖ approach. Although traditional teaching is effective in disseminating large body of content to a large number of students, it often fails to stimulate students‘ enthusiasm, confidence, and motivation, and thereby fails to enhance critical thinking and problem solving skills. The result is a mismatch in job market demand and supply as the graduates are lacking in appropriate skills and competencies needed in the job market, leading to increased unemployment among the graduates. In order to promote meaningful science education through concepts of Active Learning, number of different teaching pedagogies have been introduced, such as Problem Based Learning (PBL), Activity Based Learning (ABL) and Inquiry Based Learning (IBL). Current study focuses on the implementation of an Inquiry Based instructional design to enhance chemistry laboratory skills of undergraduates. Typically, chemistry laboratory classes utilize a ―cook book‖ approach where students follow the directions in an experimental procedure. Although this approach is effective in teaching a new laboratory technique, it highly limits the level of learning as it doesn‘t provide a comprehensive understanding of the real world applications of the experiment. In the current IBL approach, each laboratory class was composed of four components, (i) Case Study session (ii) Pre-lab Assignment (iii) Laboratory session and (iv) a Post-lab activity. Case study session was an interactive group activity where a comprehensive real world problem/scenario related to each laboratory topic was discussed prior to the laboratory session. Students were asked to think critically on the scenario, and design an experiment to solve the problem. An inclusive learning environment was created in the classroom where each group had to present their solution and provide feedback to peers. Pre-lab assignment was designed to facilitate and assess students‘ subject knowledge and logical thinking, while the post-lab activity was designed to provide a deeper understanding by emphasizing the theoretical background. Assessment of this novel IBL approach consisted of student surveys, feedbacks, and comparison of students‘ grades. Significantly higher student satisfaction and performance was observed in the study signifying the positive impact of active learning towards the success of students‘ learning.
Microbial Remediation Technologies for Mining Waste Management
(Springer, Singapore, 2024) Samarasekere, P.W.
Mining activities have significantly contributed to pollution and environmental degradation, generating vast amounts of waste that pose substantial risks to ecosystems. Conventional remediation methods often fail to address the complex nature of pollutants in mining wastes. Alternative approaches, such as microbial remediation, have emerged as promising solutions for sustainable remediation of contaminated sites. This chapter provides a detailed overview of microbial remediation technologies specifically tailored to mining and industrial waste. It explores the diversity of microorganisms capable of degrading various pollutants commonly found in these waste, including heavy metals, organic pollutants, and toxic chemicals. Additionally, it examines factors that affect microbial activity and the optimization of remediation processes. Furthermore, it highlights the advantages, limitations, and applicability of microbial remediation techniques for different types of mining and industrial waste. The chapter also discusses the challenges and considerations regarding the real-world implementation of microbial remediation. Additionally, it reviews the synergistic effects of combining different antimicrobial approaches to enhance overall efficacy and efficiency. Overall, this chapter presents a valuable resource for interested parties seeking to understand and apply microbial remediation technologies for mining and industrial waste. By harnessing the power of microbes, these techniques offer promising prospects for restoring contaminated sites, reducing environmental impacts, and promoting sustainable development.