Teaching effectively - Achieving successfully

In my thesis I am focusing on the major influences that a teacher has on the students and over lessons. Furthermore, I am writing about the methods, which with a student can be motivated. And finally, the good or harm that can be done by considering or ignoring the above mentioned. In order to find out the extent of a teacher's effects, on the one hand I was observing lessons of 13-15- year-old students. On the other hand, they were asked to fill in a questionnaire. My experiences in both cases have proved that the better a teacher takes into consideration his/her effects; the more is a student likely to study. Thus, the conclusion is that a student's achievement should be the teacher's responsibility as the teacher has a major impact on him/her, by influencing the student in many ways.