An investigation into microbiology students’ understanding of microbes

Abstract

The research aimed to investigate students' understanding of microbes. Data on understanding of microbiology concepts were collected from biotechnology students during their formal 4-month microbiology course. Written tests and semi-structured interviews were used for data collection. For 2005 cohort, 120 students participated in semester 1 pretests while 112 students participated in semester 2 pretests. Seven and 8 students from semester 1 and 2 respectively took part in the post interviews. Classroom pretest was conducted two weeks after the microbiology course commenced while post intervention interviews (post interviews) were held a week before the semester ends. For 2007 cohort, 15 students were involved in the pre and post interviews. To probe students' thinking towards understanding the nature of microbes, interview questions were devised to answer 4 sub-research questions on student ideas on terminology, living characteristics, classification and occurrence of microbes. It hoped that results gathered will provide basic considerations for future teachings in microbiology to enhance student understanding on the concepts learnt during their early phase of learning life sciences. Students generally had the idea that microbes were harmless even they knew bacteria and virus could be pathogenic to humans. Such thinking was derived from their own personal experience of not falling ill despite being exposed to the microbial organisms and having microbes in their bodies. These microbes were thought to be ubiquitous and its occurrences mainly in the aerial environment and intestinal tract. The idea of a microbe as a small living organism requiring the microscope for viewing was prevalent amongst the students. Use of dimension of organisms was unreliable and prevented them from understanding the microbiology concepts, students had most difficulty in understanding the term 'microbe' and that would have contributed to their poor conceptual understanding of microbial classification. There was no improvement on students’ understanding of microbes for 2005 cohort. Understanding microbial classification and microbial growth improved slightly for 2007 cohort, but there were no students with sound understanding on growth as a living characteristic for microbes. For the respiration concept, students knew organisms needed air to live but failed to associate the purpose of nutrients for energy release necessary for microbial reproduction, growth and movement. In reproduction, students were able to describe binary fission but were unable to explain its association with chromosomes for inheritance purposes. Limited scientific knowledge caused poor understanding when learning about virus particularly in the biological processes for viral nutrition and reproduction. Their attempt to explain ideas with limited scientific knowledge gave rise to the utilisation of anthropomorphic expressions. Case study involving 6 students of the 2007 cohort showed that there was little development on ideas for concept of classification of microbes at the end of the microbiology course. The course did not help them gained an understanding that microbes were single celled organisms capable of functioning independently. Concepts of microbial growth and living characteristics of virus were most difficult to understand and learn, students were not aware of the microbes' ability to undergo cell division rapidly. Misconceptions were also uncovered in the investigation and until these were corrected, students would continue to experience difficulty when learning microbiology. The concept model for understanding the nature of microbes was proposed with the recommendation that students should first respond with ideas on living characteristics before proceeding to classify the organisms. With adequate scientific knowledge, the concept model could enhance a better appreciation and understanding on the complex nature of microbes.