Teacher Characteristics and Student Achievements in TIMSS. Findings Gained from Applying the "First-Difference" Method to TIMSS-2007 Data

The advantage of Trends in International Mathematics and Science Study is that not only does it perform a direct cognitive assessment of students concerning these students' teachers, but also their education, work experience and the instructional strategies used in their classes. In order to estimate teachers’ characteristics effects on a student’s achievements and overcome the limits of the TIMSS' correlational design, we have employed the first-difference method. Teachers’ characteristics effects have also been measured with the usual regression method. The effects discovered varied from one subject field to another, and there has been a difference between the results gained by using the firstdifference method and OLS regression analysis model. The first-difference method has revealed a negative effect of reproductive tasks and group work in math class, whereas comprehension tasks and tasks for developing meta-cognitive skills have shown a positive effect. On the contrary, reproductive tasks for science classes have had a positive effect while comprehension tasks and tasks for developing meta-cognitive skills have had either none or negative effects. Apart from this, a teacher's experience has had a significant effect on natural science subjects as opposed to mathematics. The possible interpretations of these results are discussed in this paper.