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Asia-Pacific Forum
on Science Learning and Teaching, Volume 9, Issue 2, Article 8
(Dec., 2008)
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A total of 85 pre-service elementary school teachers, enrolled in ESN322 class, were involved in the study. ESN322, Science Instruction II, class had four 50-minute sessions per week. One of the ESN322 classes was assigned as an experimental group and the other as a control group. For this study, two sessions of the classes were used for 10 weeks during spring 2005. The post-test only control group design was used. During the research, both of the groups had the same learning objectives and were instructed by the same instructor. As opposed to the control group, there were 3 research assistants in the experimental group. The topics for the classes were composed of genetic engineering and global warming. The topics related to genetic engineering were gene cloning, the human genome project, genetic ethics, genetic products, agriculture and the topics related to global warming were effects of global warming on a sea ecosystem, the relationship of global warming with climate changes, the effects of global warming on human health and the relationship of global warming with agriculture.
In the first week of the research, the instructor asked students to form groups, each including four to five students. Each group was asked to pick a topic for their project, develop, design and present it.
Groups in the control group were responsible for giving a lecture to their classmates about their findings every week. In lecture process, the depth and quality of the information was evaluated by the instructor and their classmates.
Groups in the experimental group were responsible for the construction of necessary information and products based on the PBL approach. Hence, as the instructor provided these students with preliminary descriptions of problem-solving process and applications of PBL, she then asked them to prepare their problem sentences about their topics for the next week. In the second week of the study, the instructor and the research assistants gave feedback to the students’ problem sentences. After the instructor had shown a sample of a scenario, the students wrote their own scenarios related to their own topics. They also contacted the instructor and the research assistants for their scenarios during that week. In the third week, they constructed sub problems for their scenarios and shared their tasks. They did research for the solution of their problems during the following two weeks. The sixth week of the study mainly included brainstorming in which they tried to produce various types of solutions to their sub problems. In the seventh week, deciding on the best solution, students determined what kind of products they would prepare. Almost half of the products were constructed for the eighth week. All of the groups made their presentations in the ninth week of the study.
After this instruction period the PSSI was administered to both experimental and control group students, and an open-ended questionnaire was distributed to experimental group students. Moreover, interviews were conducted with 6 of the experimental group students.
