ABSTRACT
Decision making about socio-scientific issues (SSI), such as the applications of genetic engineering and gene therapy, is an important aspect of modern science education worldwide. The objective of this study was to explore how 17- to 18-year-old high school students make decisions about treatment of cystic fibrosis by means of gene therapy. A qualitative approach was employed to investigate the patterns of informal reasoning and how small-group discussions can affect them. Written tests and semi-structured interviews were designed to examine the students' reasoning in response to a fictional gene therapy scenario. The results indicated that the students most frequently relied on rationalistic forms of reasoning when they worked to resolve the socio-scientific dilemma. Our findings also provided evidence that there were considerable changes in the students ' decisions and reasoning patterns before and after the group activity. These results highlight the need to ensure that science classrooms are environments in which emotions and intuition in addition to reason-based reasoning are valued.