Acids-bases threshold concepts: a case of first-year students’ high failure and dropout rate

Kampamba, Royda C
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Many higher institutions of learning are concerned about freshmen failure and dropout in science programmes. University dropout affects the society, university and the individual student. It is a loss of skilled manpower; brain drain and a waste of government resources. Statics have revealed that chemistry has a higher failure and drop-out rate than other sciences in institutions of learning. In the context of students’ challenges in learning chemistry, this study investigated threshold concepts of acids-bases reactions because it is a topic that students in the researcher’s institution claimed was a challenge. Acids-bases chemistry is also one of the Threshold Concepts (TCs) of chemistry and is connected to many chemical reactions in chemistry and other science topics. This study investigated the first-year students’ experiences in learning TCs of acids-bases, first-year educators’ experiences in teaching TCs of acids-bases, causes of high failure and drop-out rates and how they can be ameliorated in the researcher’s institution. Informed and guided by the pragmatism paradigm, this study employed qualitative methodological approaches to study chemistry freshmen failure and drop-out rates. The participants were purposely sampled and included five first-year chemistry educators and five classes of first-year students (47) of the sampled educators. Qualitative data were derived from educators’ questionnaires, interviews, less on observations and post-lesson conversations. Interview questions were not the same as they emanated from an individual educator’s response to a questionnaire and from less on observations. In addition, data were collected from students’ focus group discussions. Thematic analysis was used to analyse qualitative data. The main findings of the study revealed that students’ learning and studying strategies and their prior knowledge of acids-bases conflicted with the university’s teaching strategies hence creating challenges. On the other hand, challenges led some students to construct their own meaning and to generate collaborative learning, for example, learning from more knowledgeable others (Zone of Proximal Development (ZPD)), studying late into the night with colleagues and watching online chemistry tutorials. The findings also revealed that the educators’ challenges emanated from students’ weak prior knowledge, hands-on and mind-on learning and too many students in a class. Students’ preconceived ideas that chemistry is difficult and their inconsistency in attending lessons also contributed to educators’ challenges. The challenges were alleviated by a handbook comprising out-lines and tasks on the first-year chemistry course. Furthermore, it was reported that the university’s assessment and progression policy was too demanding on students. Every academic year, students are examined in six courses. Students regard the 50% pass mark in all courses to proceed to the second year as too high. Recommendations are made for educators to employ student-centred pedagogical practices and formulate TCs of acids-bases module as a foundation course
A thesis submitted to the Wits School of Chemistry, Faculty of Science, University of the Witwatersrand, in fulfilment of the requirements of the degree of Doctor of Philosophy, 2021