Effectiveness of socio scientific issues based instruction on pre-service teachers' critical thinking skills

The significant goals of science education is conveying scientific knowledge to the individuals, teaching them to think critically, and making them scientifically literate person. Apart from these aims, in the 21st century of modern society, individuals encountered so many scientific issues which have relevances with societal concerns (SSI) in order for solving them, and making decisions about them by thinking critically. Therefore, this study was motivated by two questions firstly (1) how to improve critical thinking skills of these individuals? , and (2) does it effective to use SSI-based instruction for improving critical thinking skills? In order to investigate these questions, the study examined the impacts of SSI-based instruction on pre-service science teachers' critical thinking skills and dispositions. And, it was generally hypothesized that there will be significant difference in the pretest and the posttest scores on a measure of critical thinking skills and dispositions between SSI-based instruction participants and non-participating pre-service teachers. This dissertation aimed at two purposes as follows; (1) to investigate how ssı-based instruction improves critical thinking skills of pre-service teachers in environmental course at global warming unit, (2) to determine differences of increasement in critical thinking skills and dispositions between the treatment and the comparison groups of pre-service teachers. The literature on the SSI and SSI-based instruction focused most exclusively on science content knowledge, scince learning, motivation for science learning, epistemological development in science, attitudes towards science, informal reasoning, reasoning skills, and reflective judgment. This study bridges the literature gap between science content knowledge, science learning and sub-dimensions of reasoning skills, reflective judgment as using SSI-based instruction and critical thinking. Synthesizing the conceptual framework of SSI and SSI-based instruction with the theoritical framework of critical thinking, nature of science, and science literacy; the study was conducted pretest-posttest control group quasi-experimental study to investigate critical thinking skills and dispositions of pre-service science students in the teacher education program for six weeks in the autumn semester. The sample of the study was determined by convenient and purposive sampling and it was comprised of 90 pre-service science students in the science teacher education program at the public university in the north of Turkey. The experimental group in which SSI based instruction was implemented, consists of 45 pre-service teachers, and there were 45 pre-service teachers in the control group. Data was gathered quantitatively with the help of Turkish version of the Ennis-Weir Critical Thinking Essay Test (E-WCTET) and the California Critical Thinking Disposition Inventory (CCTDI). Aybek (2006) adapted this measurement tool in Turkish by applying it at faculty of education to 87 students as a pre and post test to both experiment and control groups. The researcher measured internal consistency coefficient values of pre and post-test .85 and .88 respectively. In this study, the researcher measured internal consistency coefficients of pre-test and post-test .79 and .83 respectively. CCTDI was adapted to Turkish by Kokdemir (2003). The researcher found the reliability value of the scale as 0.88. In this study, the internal consistency coefficients of the subscales varies from .60 to .85. The total cronbach alpha was found as .83. In this study, the analysis of covariance (ANCOVA) was used to determine the impacts of SSI based instruction on the critical thinking skills and dispositions of pre-service teachers in experiment and control groups. SSI based instruction was the independent variable, E-WCTET and CCTDI were dependent variables, and the scores of the pretests were described as 'covariate' variable. Moreover, the research was used Cohen's d in order to investigate the magnitude effect size of intervention on the pre-service teachers' critical thinking skills and dispositions. Findings of the study revealed that there is no significant difference between the treatment and the control group's critical thinking scores. However, the post-test scores of the treatment group was increased. Also, results indicated that there is a significant difference between the treatment and the control group's critical thinking dispositions scores. Results were discussed by taking the context of the SSI-based instruction, the consistent, and non-consistent literature into considerations. The reasons of increasement in the critical thinking post-test scores were attached to the context of SSI-based instruction. And, the researcher underlined the strong correlation between critical thinking skills and dispositions. As a conclusion, the study claimed that enhancing the critical thinking dispositions of the pre-service teachers leads us to enhance critical thinking skills of them.