Effect of argumentation based instruction on improvement of high school students? science process skills and critical thinking ability

This research was conducted in order to determine the change in students' scientific process skills, critical thinking skills and conceptual understanding, in case the teaching approach based on scientific argumentation is implemented in the teaching of the subjects of ?Reaction Rate?, ?Chemical Equilibrium?, ?Solubility Product?, ?Acids and Bases? units in the ?11th grade Chemistry Lesson Teaching Programme? to determine the difference of this group of students from the other student group whose members learned the above mentioned subjects through the conventional teaching approach. In addition, each pre- concept test and last-concept test was evaluated in terms of scientific process skills and critical thinking skills levels used in these tests.The research was conducted in two grade levels of a high school in the city of Çankırı. Classes were carried out with the teaching approach based on scientific argumentation in the experiment group (N=17) and with the conventional teaching approach in the control group (N=17). Applications lasted 29 weeks. Scientific process skills scale, critical thinking skills scale and the concept test for each unit was separately applied on the experiment and control group. The experiment group students were given written argumentation activities during argumentation tasks, and these activities were firstly carried out individually and then in groups of three-four people.According to the analysis results of SPSS (BSBÖ) and WGCTS (WGEDSÖ) there occurs a meaningful difference in favor of the experiment group (p=0,000), compared to the control group, between the last test point averages of scientific process and critical thinking. According to the analysis results of performance tests, again, statistically there occurs a meaningful difference in favor of the experiment group in all chapters except for ?Reaction Rate? chapter in terms of scientific process skills (p=0,109); in all the chapters except for ?Chemical Equilibrium? chapter in terms of critical thinking skills (p=0,063) and in all the chapters except for ?Chemical Equilibrium? chapter in terms of conceptual understanding (p=0,063).According to the analysis results of performance tests, in terms of chapters, compared to the control group, a meaningful difference has been found about scientific process sub skills of ?Reaction Rate? and ?Chemical Equilibrium? chapters; however, a statistically meaningful difference hasn?t been encountered in ?Solubility Product? and ?Acids and Bases? chapters. Moreover there is a meaningful difference in favor of the experiment group, compared to the control group, in terms of scientific process sub skills in total. Examining the quality of students? answers to the performance test questions, it can be seen that, argumentation-centered instruction method based on constructivist approach contributes much more to the sub-skills such as students? ?determining, changing the variables and keeping them constant?, ?to be able to define the numerical data mathematically and orally-and to be able to interpret and generalize them? and ?to be able to establish reason-result based relations while interpreting data? than the other sub-scientific process sub skills.Furthermore, it is clear that there isn?t any meaningful difference statistically between the experiment and control group students? sub skills about critical thinking when they are compared in terms of critical thinking sub skills they have gained at the very end and considering all the chapters. But when students? answers are examined in terms of quality, it can be seen that the experiment group students? all critical thinking sub skills have developed much more than the control group and this development can be seen in ?interpreting? sub-skill the most.