Investigation of variables describing science literacy of PISA 2015 Turkey sample with CHAID analysis

The aim of this research is to determine the variables that analyze science literacy in the responses of Turkish students to the PISA 2015 student questionnaire. This research has been conducted in relational screening model. In the PISA 2015 application, close to 540,000 students representing a universe of about 29 million students in 72 countries were included in the study. The universe of Turkey has 1.324.089 students in the range of 15 years 3 months to 16 years 2 months, while the achievable universe of Turkey, which can participate in the application, has 925.366 students. Population of the study covers all Turkish students who are between 15 years and 3 months old and 16 years and 2 months old. Research sample of Turkey consists from 5895 students who are chosen by stratified sampling method from this universe. Variables, which define Turkish students' science literacy were determined with items which were selected in the PISA student questionnaire. The sample of this study consists of 3052 students remaining after the data containing the lost value is extracted. In this study, one of the data mining decision trees algorithms, Automatic Chi-Square Interaction Detection (CHAID) method was used for data analysis. The results of this study indicated that the best defining variable of Turkish students' science literacy is to "the number of books in the home". Other variables that explain science literacy of Turkish students have also been studied in detail.It was observed that educational software at home, number of computers in the home, whether there is a computer using for school work at home and parental support, that are subscales of variables about student's personality, family and home, are effective to define variable of Turkish students' science literacy. In additon to these, the students' expected occupational status, that is subscale of student's personal life, is effective to define variable of Turkish students' science literacy. The number of science courses in a week at school and time for science learning, that are subscales of variables about school time and time for learning, are effective to define variable of Turkish students' science literacy. Inquiry-based science teaching and learning practices which is a subscale of science learning in school variable, is also effective effective to define variable of Turkish students' science literacy. Moreover, environmental awareness, environmental optimism, science self-efficacy and epistemological beliefs about science which are subscales of science tendency, is also effective effective to define variable of Turkish students' science literacy. In this study, the values of earnings were analyzed to determine the most effective node in separating successful and unsuccessful students. Thus, the node consisting of students with science self-efficacy, who have more than 200 books in home and attend more than 40 courses in a week at school, was determined the most effective node. The node consisting of students with parental support that encourage them to be confident, who have more than 200 books in home and attend 40 courses in a week at school, was determined the second most effective node. The node consisting of students spending more than 150 minutes for learning science lesson, who have 101-200 books in home and never be allowed to design their own experiments, was determined the third most effective node in separating successful and unsuccessful students. Besides, the node consisting of students having environmental optimism, who have less than 10 books in home and have not environmental awareness, determined the fewest effective node in separating successful and unsuccessful students.