| The purpose of this study was to explore how to enhance students' critical thinking in an introductory undergraduate science course. As a design experiment, this study aimed to design, develop, implement, and refine learning activities, and investigate how the learning activities worked in fostering students' critical thinking in a large size classroom context.;In this study, critical thinking in science was framed with six categories, 1) identifying decisions, 2) evaluating decisions, 3) providing own decision, 4) argument and justification for own decision, 5) presenting supporting data/evidence, and 6) integrating other perspectives, as the result of literature review. To enhance critical thinking, three design principles, 1) authentic task, 2) question prompts, and 3) peer interaction, were associated with the learning activities for two consecutive years.;The research context was within a large general science course and the learning activities for a module were designed, implemented and refined for two years. Specially, changes in design strategies were made in the two design principles, question prompts and peer interaction, after the 1st implementation. With regard to the use of question prompts, the students of the 2nd year were provided with procedural and elaborative question prompts, while those of the 1st year only received procedural question prompts embedded in the Group and Community Discussion Charts. Second, instead of being engaged six times in two types of discussions, group and community discussions, the students of the 2nd year were required to take part in a community discussion twice and to prepare for the discussion by learning about and understanding important aspects of dealing with the hurricane situation. For individual preparation, elaborative question prompts were embedded in the Individual Worksheet.;Quantitative and qualitative research methods were taken to investigate how the two different designs of the 1st and 2nd years worked for enhancing critical thinking in a large-size classroom. Data came from the students' written documents during and after the learning activities.;The result from the descriptive and comparative analysis on the written documents for two years indicated that there were changes in patterns of reasoning between the two years. It was evident that the groups engaged in decision-making for communities of the 2nd year showed more concrete and shaped reasoning than those of the 1st year.;The result of the t-test indicated that there was a significant difference in critical thinking demonstrated in individual reports between the students of the 1st and the 2nd years. The students of the 2nd year demonstrated better levels of critical thinking than those of the 1st year. Specially, among the six categories of critical thinking, the students of the 2nd year demonstrated better levels in three categories, 1) providing one's own decision, 2) argumentation and justification for one's own decision, and 3) integrating other perspectives, than those of the 1st year.;By the multiple-case study method, four themes were found to explain what made students demonstrated higher levels of critical thinking: 1) understanding of one's assigned role, 2) linking roles to make decisions, 3) answers to the question prompts, and 4) use of data and source, were raised in explaining the different pattern between the students with higher and lower levels of critical thinking. Also, a trend was visible across artifacts for higher performing students in both years. |
