Conceptions of Germs: Expert to Novice Understandings of Microorganisms

Abstract

This study describes 5th, 8th, and 11th-grade students', teachers', and medical professionals' conceptions of microorganisms. Participants constructed drawings of 2 different types of "germs" and participated in a semi-structured interview designed to elicit understandings of microbe morphology, characteristics, and types. The findings showed students, teachers and medical professionals possess different understandings of bacteria and viruses. These understandings ranged from the novice (elementary, middle, and high school students and teachers) to more expert conceptions (high school teachers and medical professionals). Participants held incomplete knowledge for: (a) microbe characteristics, (b) where microbes are found, (c) differences that exist between bacteria and viruses, and (d) the role of microbes in the environment. The youngest students drew heavily upon personal experiences and media representations for sources of their knowledge rather than formal instruction. Students tended to view microbes as a human problem rather than seeing microorganisms as an independent member of the ecosystem. Teachers' explanations concepts of microbes varied in explicitness based on the grade level they taught while medical professionals based their understandings on technical, formal knowledge.